Today's Message Index:
----------------------
1. 02:15 PM - Engine driven fuel Pump replacement tips (Tim Olson)
2. 02:34 PM - Re: Engine driven fuel Pump replacement tips (Phil Perry)
3. 02:50 PM - Re: Engine driven fuel Pump replacement tips (Lenard Iszak)
4. 03:10 PM - Re: Engine driven fuel Pump replacement tips (Kelly McMullen)
5. 03:35 PM - Re: Engine driven fuel Pump replacement tips (Lyle Peterson)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Engine driven fuel Pump replacement tips |
Hi all, this was sent to me by Dan Masys to be posted as he is having
issues posting.
With about 1200 hrs and 13 years since new, my factory-new IO-540 D4A5
is beginning to show signs of not being so factory-new any more. In the
past month or so, fuel pressures have been drifting down to as low as
10-12 psi on extended climbs to altitudes above 10,000 MSL and although
the engine has never stumbled, I figured it would be prudent to swap out
the engine driven pump before anything dramatic happened.
Turns out replacing the pump on the back of the accessory case is quite
a bit trickier than it should be, given that it is just held on by a
couple of specialized allen head capscrew/bolts. After several of
thrashing and cussing, I figured I'd better Google the topic and see
what the story is. I found the difficulty replacing the Lycoming pump
has been experienced by lots of RV builders, and there is a fair amount
of creative disinformation out there -- workarounds that RVers took to
grind down or shorten bolts, weird installation techniques, etc. But I
did find the correct method, and when using it, the installation was
pretty much a breeze.
Since this is all fresh in my mind, I thought I would pay it forward
with a little tutorial on the subject as it relates to the RV-10. Here
goes:
The issues
1. This is a big deal. There is at least one NTSB report of a fatal
RV-7 crash caused by incorrect replacement installation of the engine
driven fuel pump.
2. There are more ways to do it wrong than to do it right. The
instructions that came with the Tempest replacement pump I got from
Spruce show you the incorrect positionings to avoid, and tell you that
the pushrod that presses from above onto the pump's actuator arm has to
be in full up position, but they don't tell you how to do either of
those things.
3. Although the RV-10 has lots more space between the engine and the
firewall than most RV's, for this procedure all kinds of things are
going to be in your way: spark plug cable bundles, SCAT tubing for oil
cooler, wiring to magnetos and/or electronic ignition.
4. The major gotcha is that the lever arm of the fuel pump has to be
positioned under the end of the vertical pushrod that drives it before
bolting anything in place, but the special bolts can't be inserted in
the fuel pump flange if you do that first -- they hit the body of the
pump and can't be lined up with the threaded holes in the case.
The solutions to the above issues
1. Start with the right set of tools. You will need a small ladder to
get up and over the engine (probably the same one you use to change the
oil filter.) You also need a set of stubby combination wrenches, a 5/16
allen wrench with a ball/swivel style head and about a 4 inch long shaft
or so. A 5/16 inch standard length combination wrench can be used to
turn the allen wrench from the side for tightening and loosening the
special bolts.
2. Once you have removed the old pump with its hoses disconnected but
fittings still attached, put it aside on a workbench.
3. Remove one spark plug from all six cylinders -- bottom plugs are
easiest.
4. Key point: in order to determine whether the engine driven pushrod is
in its maximum up position, you have to put your hand into the fuel pump
mounting hole and *put your finger on the bottom of the pushrod.* Push
it up as far as it will go. Then, while holding it up, rotate the prop
with the other hand at least two full turns so you can determine where
'top dead center' is on the pushrod. When you are satisfied that you
know where the full up position is, leave the prop in that position and
don't move it again until the new pump is in. Now take your finger off
the pushrod. You will notice it immediately slides back down to its
lowest position (!!) even though the cam driving it is in its highest
position. (This is why you can't use an inspection mirror to determine
the position of the pushrod.)
Some RVers apparently have gone to great lengths to try to get the shaft
to stay up so the pump arm can be inserted, but it turns out this is not
necessary. Just let it fall to its lowest position.
5. On the bench, swap the B nut fittings from the old pump to the new
one. I found that I had to leave off the overflow fitting during
initial installation due to interference with spark plug wire bundles
and oil cooler SCAT tubing.
6. Place the new gasket on the mounting flange of the new pump. You
might need a little dab of fuel lube to hold it in place even though it
is a dry gasket seal. Insert the two mounting bolts fully before
starting the attach procedure (they won't fit later if not inserted now.)
7. Key point: While holding the pump with its actuator arm pointed into
the engine case, engage the bolt holes for the two mounting bolts, but
only advance the bolts *one turn* or at most two. This is the
difference between success and failure. With the bolts engaged only one
turn, you will be able to tilt the fuel pump actuator down so that it
slips underneath that pesky pushrod which fell to its lowest position.
If you tighten the bolts any more than that, the actuator arm will hit
the side of the pushrod and you will not be able to seat the pump.
8. You will know you are successful if the pump flange slides forward
easily on the bolts and mates to the mounting surface of the engine
accessory case with no resistance whatsoever. Anything else is no bueno
-- pull the pump out and start again. (The fatal RV crash occurred
because the builder cranked the bolts down in spite of interference and
bent the pushrod shaft.)
9. Once the pump flange sits flat against the engine, hold the pump in
place with one hand and tighten the bolts on both sides with the 5/16
inch allen wrench with the other.
10. Safety wire the special bolts to each other. (Also a bit of an
adventure, but this one is left as an exercise for the student. ;-) ).
11. Reconnect in inflow, outflow and overflow lines to the pump.
Replace lower spark plugs (new gaskets, of course), and oil filter.
Start engine and do a leak test and fuel pressure test.
Hope this helps if you should find yourself needing to replace the
engine driven pump on your Lycoming. Remember, if you are having to
force anything, the new pump is not in its correct position. Happy flying.
Dan Masys
RV-10 N104LD
Tech counselor, EAA chapter 1541
----------------------------------------------------
In addition to Dan's comments, I would add this: As Dan notes, the
holes are oblong and it appears designed to tilt the pump as you install
it under the pushrod. That said, what I have had good luck with is
this: I have used fine safety wire, or you could use dental floss, to
run a couple of twists around that push rod, and then pull the thread
out and tie it to the engine case or engine mount snugly. That will hold
the push rod up. If you follow Dan's guidance, it shouldn't be
necessary to hold the rod up, but myself I would prefer to have as much
gap there as possible to ensure the rod gets in proper position on top
of the lever. Just make sure whatever you use is removed completely
before you fully seat the pump.
Hopefully Dan's post comes in handy for some of you.
Tim
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Engine driven fuel Pump replacement tips |
That's a good technique. I replaced two of them and it never was easy.
Next time I will have to try and tilt the pump a bit and see if that does
the trick.
I have always used the safety wire method too and it has worked reasonably
well. I've also heard of people jamming a tooth pick alongside the
actuator to hold it up; then snapping off the toothpick. The tip of the
tooth pick later passed through the system (supposedly). I'm not a fan of
that method.
Thanks for another alternative.
Phil
On Sun, Mar 15, 2020 at 4:20 PM Tim Olson <Tim@myrv10.com> wrote:
> Hi all, this was sent to me by Dan Masys to be posted as he is having
> issues posting.
>
> With about 1200 hrs and 13 years since new, my factory-new IO-540 D4A5 is
> beginning to show signs of not being so factory-new any more. In the pas
t
> month or so, fuel pressures have been drifting down to as low as 10-12 ps
i
> on extended climbs to altitudes above 10,000 MSL and although the engine
> has never stumbled, I figured it would be prudent to swap out the engine
> driven pump before anything dramatic happened.
>
> Turns out replacing the pump on the back of the accessory case is quite a
> bit trickier than it should be, given that it is just held on by a couple
> of specialized allen head capscrew/bolts. After several of thrashing and
> cussing, I figured I'd better Google the topic and see what the story is.
> I found the difficulty replacing the Lycoming pump has been experienced b
y
> lots of RV builders, and there is a fair amount of creative disinformatio
n
> out there -- workarounds that RVers took to grind down or shorten bolts,
> weird installation techniques, etc. But I did find the correct method, a
nd
> when using it, the installation was pretty much a breeze.
>
> Since this is all fresh in my mind, I thought I would pay it forward with
> a little tutorial on the subject as it relates to the RV-10. Here goes:
>
> The issues
>
> 1. This is a big deal. There is at least one NTSB report of a fatal RV-7
> crash caused by incorrect replacement installation of the engine driven
> fuel pump.
>
> 2. There are more ways to do it wrong than to do it right. The
> instructions that came with the Tempest replacement pump I got from Spruc
e
> show you the incorrect positionings to avoid, and tell you that the pushr
od
> that presses from above onto the pump's actuator arm has to be in full up
> position, but they don't tell you how to do either of those things.
>
> 3. Although the RV-10 has lots more space between the engine and the
> firewall than most RV's, for this procedure all kinds of things are going
> to be in your way: spark plug cable bundles, SCAT tubing for oil cooler,
> wiring to magnetos and/or electronic ignition.
>
> 4. The major gotcha is that the lever arm of the fuel pump has to be
> positioned under the end of the vertical pushrod that drives it before
> bolting anything in place, but the special bolts can't be inserted in the
> fuel pump flange if you do that first -- they hit the body of the pump an
d
> can't be lined up with the threaded holes in the case.
>
> The solutions to the above issues
>
> 1. Start with the right set of tools. You will need a small ladder to ge
t
> up and over the engine (probably the same one you use to change the oil
> filter.) You also need a set of stubby combination wrenches, a 5/16 alle
n
> wrench with a ball/swivel style head and about a 4 inch long shaft or so.
> A 5/16 inch standard length combination wrench can be used to turn the
> allen wrench from the side for tightening and loosening the special bolts
.
>
> 2. Once you have removed the old pump with its hoses disconnected but
> fittings still attached, put it aside on a workbench.
>
> 3. Remove one spark plug from all six cylinders -- bottom plugs are
> easiest.
>
> 4. Key point: in order to determine whether the engine driven pushrod is
> in its maximum up position, you have to put your hand into the fuel pump
> mounting hole and *put your finger on the bottom of the pushrod.* Push i
t
> up as far as it will go. Then, while holding it up, rotate the prop with
> the other hand at least two full turns so you can determine where 'top de
ad
> center' is on the pushrod. When you are satisfied that you know where th
e
> full up position is, leave the prop in that position and don't move it
> again until the new pump is in. Now take your finger off the pushrod. Y
ou
> will notice it immediately slides back down to its lowest position (!!)
> even though the cam driving it is in its highest position. (This is why
> you can't use an inspection mirror to determine the position of the
> pushrod.)
>
> Some RVers apparently have gone to great lengths to try to get the shaft
> to stay up so the pump arm can be inserted, but it turns out this is not
> necessary. Just let it fall to its lowest position.
>
> 5. On the bench, swap the B nut fittings from the old pump to the new
> one. I found that I had to leave off the overflow fitting during initial
> installation due to interference with spark plug wire bundles and oil
> cooler SCAT tubing.
>
> 6. Place the new gasket on the mounting flange of the new pump. You migh
t
> need a little dab of fuel lube to hold it in place even though it is a dr
y
> gasket seal. Insert the two mounting bolts fully before starting the atta
ch
> procedure (they won't fit later if not inserted now.)
>
> 7. Key point: While holding the pump with its actuator arm pointed into
> the engine case, engage the bolt holes for the two mounting bolts, but on
ly
> advance the bolts *one turn* or at most two. This is the difference
> between success and failure. With the bolts engaged only one turn, you
> will be able to tilt the fuel pump actuator down so that it slips
> underneath that pesky pushrod which fell to its lowest position. If you
> tighten the bolts any more than that, the actuator arm will hit the side
of
> the pushrod and you will not be able to seat the pump.
>
> 8. You will know you are successful if the pump flange slides forward
> easily on the bolts and mates to the mounting surface of the engine
> accessory case with no resistance whatsoever. Anything else is no bueno
--
> pull the pump out and start again. (The fatal RV crash occurred because
> the builder cranked the bolts down in spite of interference and bent the
> pushrod shaft.)
>
> 9. Once the pump flange sits flat against the engine, hold the pump in
> place with one hand and tighten the bolts on both sides with the 5/16 inc
h
> allen wrench with the other.
>
> 10. Safety wire the special bolts to each other. (Also a bit of an
> adventure, but this one is left as an exercise for the student. ;-) ).
>
> 11. Reconnect in inflow, outflow and overflow lines to the pump. Replace
> lower spark plugs (new gaskets, of course), and oil filter. Start engine
> and do a leak test and fuel pressure test.
>
> Hope this helps if you should find yourself needing to replace the engine
> driven pump on your Lycoming. Remember, if you are having to force
> anything, the new pump is not in its correct position. Happy flying.
>
> Dan Masys
> RV-10 N104LD
> Tech counselor, EAA chapter 1541
>
> ----------------------------------------------------
>
> In addition to Dan's comments, I would add this: As Dan notes, the holes
> are oblong and it appears designed to tilt the pump as you install it und
er
> the pushrod. That said, what I have had good luck with is this: I have
> used fine safety wire, or you could use dental floss, to run a couple of
> twists around that push rod, and then pull the thread out and tie it to t
he
> engine case or engine mount snugly. That will hold the push rod up. If y
ou
> follow Dan's guidance, it shouldn't be necessary to hold the rod up, but
> myself I would prefer to have as much gap there as possible to ensure the
> rod gets in proper position on top of the lever. Just make sure whatever
> you use is removed completely before you fully seat the pump.
>
> Hopefully Dan's post comes in handy for some of you.
> Tim
>
>
--
*Phil Perry, *EAA Lifetime #834284
President, EAA Chapter 59 - Waco, Texas
EAA=94*The Spirit of Aviation*
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Engine driven fuel Pump replacement tips |
I used lacing tape, it=99s nice and grippy. One turn around the actuat
or pin and then tied it to the engine mount. Once the pump is in place untie
the tape and it comes right out.
Lenny
> On Mar 15, 2020, at 5:41 PM, Phil Perry <philperry9@gmail.com> wrote:
>
> =EF=BB
> That's a good technique. I replaced two of them and it never was easy. N
ext time I will have to try and tilt the pump a bit and see if that does the
trick.
>
> I have always used the safety wire method too and it has worked reasonably
well. I've also heard of people jamming a tooth pick alongside the actuato
r to hold it up; then snapping off the toothpick. The tip of the tooth pic
k later passed through the system (supposedly). I'm not a fan of that metho
d.
>
> Thanks for another alternative.
>
> Phil
>
>
>
>
>> On Sun, Mar 15, 2020 at 4:20 PM Tim Olson <Tim@myrv10.com> wrote:
>> Hi all, this was sent to me by Dan Masys to be posted as he is having iss
ues posting.
>>
>> With about 1200 hrs and 13 years since new, my factory-new IO-540 D4A5 is
beginning to show signs of not being so factory-new any more. In the past m
onth or so, fuel pressures have been drifting down to as low as 10-12 psi on
extended climbs to altitudes above 10,000 MSL and although the engine has n
ever stumbled, I figured it would be prudent to swap out the engine driven p
ump before anything dramatic happened.
>>
>> Turns out replacing the pump on the back of the accessory case is quite a
bit trickier than it should be, given that it is just held on by a couple o
f specialized allen head capscrew/bolts. After several of thrashing and cus
sing, I figured I'd better Google the topic and see what the story is. I fo
und the difficulty replacing the Lycoming pump has been experienced by lots o
f RV builders, and there is a fair amount of creative disinformation out the
re -- workarounds that RVers took to grind down or shorten bolts, weird inst
allation techniques, etc. But I did find the correct method, and when using
it, the installation was pretty much a breeze.
>>
>> Since this is all fresh in my mind, I thought I would pay it forward with
a little tutorial on the subject as it relates to the RV-10. Here goes:
>>
>> The issues
>>
>> 1. This is a big deal. There is at least one NTSB report of a fatal RV-7
crash caused by incorrect replacement installation of the engine driven fue
l pump.
>>
>> 2. There are more ways to do it wrong than to do it right. The instructi
ons that came with the Tempest replacement pump I got from Spruce show you t
he incorrect positionings to avoid, and tell you that the pushrod that press
es from above onto the pump's actuator arm has to be in full up position, bu
t they don't tell you how to do either of those things.
>>
>> 3. Although the RV-10 has lots more space between the engine and the fire
wall than most RV's, for this procedure all kinds of things are going to be i
n your way: spark plug cable bundles, SCAT tubing for oil cooler, wiring to m
agnetos and/or electronic ignition.
>>
>> 4. The major gotcha is that the lever arm of the fuel pump has to be pos
itioned under the end of the vertical pushrod that drives it before bolting a
nything in place, but the special bolts can't be inserted in the fuel pump f
lange if you do that first -- they hit the body of the pump and can't be lin
ed up with the threaded holes in the case.
>>
>> The solutions to the above issues
>>
>> 1. Start with the right set of tools. You will need a small ladder to ge
t up and over the engine (probably the same one you use to change the oil fi
lter.) You also need a set of stubby combination wrenches, a 5/16 allen wre
nch with a ball/swivel style head and about a 4 inch long shaft or so. A 5/
16 inch standard length combination wrench can be used to turn the allen wre
nch from the side for tightening and loosening the special bolts.
>>
>> 2. Once you have removed the old pump with its hoses disconnected but fit
tings still attached, put it aside on a workbench.
>>
>> 3. Remove one spark plug from all six cylinders -- bottom plugs are easie
st.
>>
>> 4. Key point: in order to determine whether the engine driven pushrod is i
n its maximum up position, you have to put your hand into the fuel pump moun
ting hole and *put your finger on the bottom of the pushrod.* Push it up as
far as it will go. Then, while holding it up, rotate the prop with the oth
er hand at least two full turns so you can determine where 'top dead center'
is on the pushrod. When you are satisfied that you know where the full up p
osition is, leave the prop in that position and don't move it again until th
e new pump is in. Now take your finger off the pushrod. You will notice it
immediately slides back down to its lowest position (!!) even though the ca
m driving it is in its highest position. (This is why you can't use an insp
ection mirror to determine the position of the pushrod.)
>>
>> Some RVers apparently have gone to great lengths to try to get the shaft t
o stay up so the pump arm can be inserted, but it turns out this is not nece
ssary. Just let it fall to its lowest position.
>>
>> 5. On the bench, swap the B nut fittings from the old pump to the new one
. I found that I had to leave off the overflow fitting during initial insta
llation due to interference with spark plug wire bundles and oil cooler SCAT
tubing.
>>
>> 6. Place the new gasket on the mounting flange of the new pump. You migh
t need a little dab of fuel lube to hold it in place even though it is a dry
gasket seal. Insert the two mounting bolts fully before starting the attach
procedure (they won't fit later if not inserted now.)
>>
>> 7. Key point: While holding the pump with its actuator arm pointed into t
he engine case, engage the bolt holes for the two mounting bolts, but only a
dvance the bolts *one turn* or at most two. This is the difference between s
uccess and failure. With the bolts engaged only one turn, you will be able t
o tilt the fuel pump actuator down so that it slips underneath that pesky pu
shrod which fell to its lowest position. If you tighten the bolts any more t
han that, the actuator arm will hit the side of the pushrod and you will not
be able to seat the pump.
>>
>> 8. You will know you are successful if the pump flange slides forward ea
sily on the bolts and mates to the mounting surface of the engine accessory c
ase with no resistance whatsoever. Anything else is no bueno -- pull the pu
mp out and start again. (The fatal RV crash occurred because the builder cr
anked the bolts down in spite of interference and bent the pushrod shaft.)
>>
>> 9. Once the pump flange sits flat against the engine, hold the pump in pl
ace with one hand and tighten the bolts on both sides with the 5/16 inch all
en wrench with the other.
>>
>> 10. Safety wire the special bolts to each other. (Also a bit of an adven
ture, but this one is left as an exercise for the student. ;-) ).
>>
>> 11. Reconnect in inflow, outflow and overflow lines to the pump. Replace
lower spark plugs (new gaskets, of course), and oil filter. Start engine a
nd do a leak test and fuel pressure test.
>>
>> Hope this helps if you should find yourself needing to replace the engine
driven pump on your Lycoming. Remember, if you are having to force anythin
g, the new pump is not in its correct position. Happy flying.
>>
>> Dan Masys
>> RV-10 N104LD
>> Tech counselor, EAA chapter 1541
>>
>> ----------------------------------------------------
>>
>> In addition to Dan's comments, I would add this: As Dan notes, the holes
are oblong and it appears designed to tilt the pump as you install it under
the pushrod. That said, what I have had good luck with is this: I have use
d fine safety wire, or you could use dental floss, to run a couple of twists
around that push rod, and then pull the thread out and tie it to the engine
case or engine mount snugly. That will hold the push rod up. If you follow
Dan's guidance, it shouldn't be necessary to hold the rod up, but myself I w
ould prefer to have as much gap there as possible to ensure the rod gets in p
roper position on top of the lever. Just make sure whatever you use is remov
ed completely before you fully seat the pump.
>>
>> Hopefully Dan's post comes in handy for some of you.
>> Tim
>>
>
>
> --
> Phil Perry, EAA Lifetime #834284
> President, EAA Chapter 59 - Waco, Texas
> EAA=94The Spirit of Aviation
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Engine driven fuel Pump replacement tips |
Good write up. One tool tip that will give more clearance is to beg,
borrow, buy or steal the correct size allen socket. Much easier to use than
an L shaped allen wrench. Thankfully my RV hasn't needed one yet, but I did
have to change one on my previous Mooney. That was lots of fun as well.
Kelly
Sent from my TRS-80 Model 100
On Sun, Mar 15, 2020 at 2:38 PM Phil Perry <philperry9@gmail.com> wrote:
> That's a good technique. I replaced two of them and it never was easy.
> Next time I will have to try and tilt the pump a bit and see if that does
> the trick.
>
> I have always used the safety wire method too and it has worked reasonabl
y
> well. I've also heard of people jamming a tooth pick alongside the
> actuator to hold it up; then snapping off the toothpick. The tip of the
> tooth pick later passed through the system (supposedly). I'm not a fan o
f
> that method.
>
> Thanks for another alternative.
>
> Phil
>
>
> On Sun, Mar 15, 2020 at 4:20 PM Tim Olson <Tim@myrv10.com> wrote:
>
>> Hi all, this was sent to me by Dan Masys to be posted as he is having
>> issues posting.
>>
>> With about 1200 hrs and 13 years since new, my factory-new IO-540 D4A5 i
s
>> beginning to show signs of not being so factory-new any more. In the pa
st
>> month or so, fuel pressures have been drifting down to as low as 10-12 p
si
>> on extended climbs to altitudes above 10,000 MSL and although the engine
>> has never stumbled, I figured it would be prudent to swap out the engine
>> driven pump before anything dramatic happened.
>>
>> Turns out replacing the pump on the back of the accessory case is quite
a
>> bit trickier than it should be, given that it is just held on by a coupl
e
>> of specialized allen head capscrew/bolts. After several of thrashing an
d
>> cussing, I figured I'd better Google the topic and see what the story is
.
>> I found the difficulty replacing the Lycoming pump has been experienced
by
>> lots of RV builders, and there is a fair amount of creative disinformati
on
>> out there -- workarounds that RVers took to grind down or shorten bolts,
>> weird installation techniques, etc. But I did find the correct method,
and
>> when using it, the installation was pretty much a breeze.
>>
>> Since this is all fresh in my mind, I thought I would pay it forward wit
h
>> a little tutorial on the subject as it relates to the RV-10. Here goes:
>>
>> The issues
>>
>> 1. This is a big deal. There is at least one NTSB report of a fatal RV-
7
>> crash caused by incorrect replacement installation of the engine driven
>> fuel pump.
>>
>> 2. There are more ways to do it wrong than to do it right. The
>> instructions that came with the Tempest replacement pump I got from Spru
ce
>> show you the incorrect positionings to avoid, and tell you that the push
rod
>> that presses from above onto the pump's actuator arm has to be in full u
p
>> position, but they don't tell you how to do either of those things.
>>
>> 3. Although the RV-10 has lots more space between the engine and the
>> firewall than most RV's, for this procedure all kinds of things are goin
g
>> to be in your way: spark plug cable bundles, SCAT tubing for oil cooler,
>> wiring to magnetos and/or electronic ignition.
>>
>> 4. The major gotcha is that the lever arm of the fuel pump has to be
>> positioned under the end of the vertical pushrod that drives it before
>> bolting anything in place, but the special bolts can't be inserted in th
e
>> fuel pump flange if you do that first -- they hit the body of the pump a
nd
>> can't be lined up with the threaded holes in the case.
>>
>> The solutions to the above issues
>>
>> 1. Start with the right set of tools. You will need a small ladder to
>> get up and over the engine (probably the same one you use to change the
oil
>> filter.) You also need a set of stubby combination wrenches, a 5/16 all
en
>> wrench with a ball/swivel style head and about a 4 inch long shaft or so
.
>> A 5/16 inch standard length combination wrench can be used to turn the
>> allen wrench from the side for tightening and loosening the special bolt
s.
>>
>> 2. Once you have removed the old pump with its hoses disconnected but
>> fittings still attached, put it aside on a workbench.
>>
>> 3. Remove one spark plug from all six cylinders -- bottom plugs are
>> easiest.
>>
>> 4. Key point: in order to determine whether the engine driven pushrod is
>> in its maximum up position, you have to put your hand into the fuel pump
>> mounting hole and *put your finger on the bottom of the pushrod.* Push
it
>> up as far as it will go. Then, while holding it up, rotate the prop wit
h
>> the other hand at least two full turns so you can determine where 'top d
ead
>> center' is on the pushrod. When you are satisfied that you know where t
he
>> full up position is, leave the prop in that position and don't move it
>> again until the new pump is in. Now take your finger off the pushrod.
You
>> will notice it immediately slides back down to its lowest position (!!)
>> even though the cam driving it is in its highest position. (This is why
>> you can't use an inspection mirror to determine the position of the
>> pushrod.)
>>
>> Some RVers apparently have gone to great lengths to try to get the shaft
>> to stay up so the pump arm can be inserted, but it turns out this is not
>> necessary. Just let it fall to its lowest position.
>>
>> 5. On the bench, swap the B nut fittings from the old pump to the new
>> one. I found that I had to leave off the overflow fitting during initia
l
>> installation due to interference with spark plug wire bundles and oil
>> cooler SCAT tubing.
>>
>> 6. Place the new gasket on the mounting flange of the new pump. You
>> might need a little dab of fuel lube to hold it in place even though it
is
>> a dry gasket seal. Insert the two mounting bolts fully before starting t
he
>> attach procedure (they won't fit later if not inserted now.)
>>
>> 7. Key point: While holding the pump with its actuator arm pointed into
>> the engine case, engage the bolt holes for the two mounting bolts, but o
nly
>> advance the bolts *one turn* or at most two. This is the difference
>> between success and failure. With the bolts engaged only one turn, you
>> will be able to tilt the fuel pump actuator down so that it slips
>> underneath that pesky pushrod which fell to its lowest position. If you
>> tighten the bolts any more than that, the actuator arm will hit the side
of
>> the pushrod and you will not be able to seat the pump.
>>
>> 8. You will know you are successful if the pump flange slides forward
>> easily on the bolts and mates to the mounting surface of the engine
>> accessory case with no resistance whatsoever. Anything else is no bueno
--
>> pull the pump out and start again. (The fatal RV crash occurred because
>> the builder cranked the bolts down in spite of interference and bent the
>> pushrod shaft.)
>>
>> 9. Once the pump flange sits flat against the engine, hold the pump in
>> place with one hand and tighten the bolts on both sides with the 5/16 in
ch
>> allen wrench with the other.
>>
>> 10. Safety wire the special bolts to each other. (Also a bit of an
>> adventure, but this one is left as an exercise for the student. ;-) ).
>>
>> 11. Reconnect in inflow, outflow and overflow lines to the pump. Replac
e
>> lower spark plugs (new gaskets, of course), and oil filter. Start engin
e
>> and do a leak test and fuel pressure test.
>>
>> Hope this helps if you should find yourself needing to replace the engin
e
>> driven pump on your Lycoming. Remember, if you are having to force
>> anything, the new pump is not in its correct position. Happy flying.
>>
>> Dan Masys
>> RV-10 N104LD
>> Tech counselor, EAA chapter 1541
>>
>> ----------------------------------------------------
>>
>> In addition to Dan's comments, I would add this: As Dan notes, the hole
s
>> are oblong and it appears designed to tilt the pump as you install it un
der
>> the pushrod. That said, what I have had good luck with is this: I have
>> used fine safety wire, or you could use dental floss, to run a couple of
>> twists around that push rod, and then pull the thread out and tie it to
the
>> engine case or engine mount snugly. That will hold the push rod up. If
you
>> follow Dan's guidance, it shouldn't be necessary to hold the rod up, but
>> myself I would prefer to have as much gap there as possible to ensure th
e
>> rod gets in proper position on top of the lever. Just make sure whatever
>> you use is removed completely before you fully seat the pump.
>>
>> Hopefully Dan's post comes in handy for some of you.
>> Tim
>>
>>
>
> --
>
> *Phil Perry, *EAA Lifetime #834284
>
> President, EAA Chapter 59 - Waco, Texas
>
> EAA=94*The Spirit of Aviation*
>
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Engine driven fuel Pump replacement tips |
Chevrolet V8s have the same problem with the push rod. It will fall out
if not held in some way. What I use is a bit of grease on the push
rod. Other materials may seem more suitable in an airplane engine.
What ever you're comfortable with.
On 3/15/2020 5:07 PM, Kelly McMullen wrote:
> Good write up. One tool tip that will give more clearance is to beg,
> borrow, buy or steal the correct size allen socket. Much easier to use
> than an L shaped allen wrench. Thankfully my RV hasn't needed one yet,
> but I did have to change one on my previous Mooney. That was lots of
> fun as well.
> Kelly
> Sent from myTRS-80 Model 100
>
>
> On Sun, Mar 15, 2020 at 2:38 PM Phil Perry <philperry9@gmail.com
> <mailto:philperry9@gmail.com>> wrote:
>
> That's a good technique. I replacedtwo of them and it never was
> easy. Next time I will have to try and tilt the pump a bit and
> see if that does the trick.
>
> I have always used the safety wire method too and it has worked
> reasonably well. I've also heard of people jamming a tooth pick
> alongside the actuator to hold it up; then snapping off the
> toothpick. The tip of the tooth pick later passed through the
> system (supposedly). I'm not a fan of that method.
>
> Thanks for another alternative.
>
> Phil
>
>
> On Sun, Mar 15, 2020 at 4:20 PM Tim Olson <Tim@myrv10.com
> <mailto:Tim@myrv10.com>> wrote:
>
> Hi all, this was sent to me by Dan Masys to be posted as he is
> having issues posting.
>
> With about 1200 hrs and 13 years since new, my factory-new
> IO-540 D4A5 is beginning to show signs of not being so
> factory-new any more. In the past month or so, fuel pressures
> have been drifting down to as low as 10-12 psi on extended
> climbs to altitudes above 10,000 MSL and although the engine
> has never stumbled, I figured it would be prudent to swap out
> the engine driven pump before anything dramatic happened.
>
> Turns out replacing the pump on the back of the accessory case
> is quite a bit trickier than it should be, given that it is
> just held on by a couple of specialized allen head
> capscrew/bolts. After several of thrashing and cussing, I
> figured I'd better Google the topic and see what the story
> is. I found the difficulty replacing the Lycoming pump has
> been experienced by lots of RV builders, and there is a fair
> amount of creative disinformation out there -- workarounds
> that RVers took to grind down or shorten bolts, weird
> installation techniques, etc. But I did find the correct
> method, and when using it, the installation was pretty much a
> breeze.
>
> Since this is all fresh in my mind, I thought I would pay it
> forward with a little tutorial on the subject as it relates to
> the RV-10. Here goes:
>
> The issues
>
> 1. This is a big deal. There is at least one NTSB report of a
> fatal RV-7 crash caused by incorrect replacement installation
> of the engine driven fuel pump.
>
> 2. There are more ways to do it wrong than to do it right.
> The instructions that came with the Tempest replacement pump I
> got from Spruce show you the incorrect positionings to avoid,
> and tell you that the pushrod that presses from above onto the
> pump's actuator arm has to be in full up position, but they
> don't tell you how to do either of those things.
>
> 3. Although the RV-10 has lots more space between the engine
> and the firewall than most RV's, for this procedure all kinds
> of things are going to be in your way: spark plug cable
> bundles, SCAT tubing for oil cooler, wiring to magnetos and/or
> electronic ignition.
>
> 4. The major gotcha is that the lever arm of the fuel pump
> has to be positioned under the end of the vertical pushrod
> that drives it before bolting anything in place, but the
> special bolts can't be inserted in the fuel pump flange if you
> do that first -- they hit the body of the pump and can't be
> lined up with the threaded holes in the case.
>
> The solutions to the above issues
>
> 1. Start with the right set of tools. You will need a small
> ladder to get up and over the engine (probably the same one
> you use to change the oil filter.) You also need a set of
> stubby combination wrenches, a 5/16 allen wrench with a
> ball/swivel style head and about a 4 inch long shaft or so. A
> 5/16 inch standard length combination wrench can be used to
> turn the allen wrench from the side for tightening and
> loosening the special bolts.
>
> 2. Once you have removed the old pump with its hoses
> disconnected but fittings still attached, put it aside on a
> workbench.
>
> 3. Remove one spark plug from all six cylinders -- bottom
> plugs are easiest.
>
> 4. Key point: in order to determine whether the engine driven
> pushrod is in its maximum up position, you have to put your
> hand into the fuel pump mounting hole and *put your finger on
> the bottom of the pushrod.* Push it up as far as it will go.
> Then, while holding it up, rotate the prop with the other hand
> at least two full turns so you can determine where 'top dead
> center' is on the pushrod. When you are satisfied that you
> know where the full up position is, leave the prop in that
> position and don't move it again until the new pump is in.
> Now take your finger off the pushrod. You will notice it
> immediately slides back down to its lowest position (!!) even
> though the cam driving it is in its highest position. (This is
> why you can't use an inspection mirror to determine the
> position of the pushrod.)
>
> Some RVers apparently have gone to great lengths to try to get
> the shaft to stay up so the pump arm can be inserted, but it
> turns out this is not necessary. Just let it fall to its
> lowest position.
>
> 5. On the bench, swap the B nut fittings from the old pump to
> the new one. I found that I had to leave off the overflow
> fitting during initial installation due to interference with
> spark plug wire bundles and oil cooler SCAT tubing.
>
> 6. Place the new gasket on the mounting flange of the new
> pump. You might need a little dab of fuel lube to hold it in
> place even though it is a dry gasket seal. Insert the two
> mounting bolts fully before starting the attach procedure
> (they won't fit later if not inserted now.)
>
> 7. Key point: While holding the pump with its actuator arm
> pointed into the engine case, engage the bolt holes for the
> two mounting bolts, but only advance the bolts *one turn* or
> at most two. This is the difference between success and
> failure. With the bolts engaged only one turn, you will be
> able to tilt the fuel pump actuator down so that it slips
> underneath that pesky pushrod which fell to its lowest
> position. If you tighten the bolts any more than that, the
> actuator arm will hit the side of the pushrod and you will not
> be able to seat the pump.
>
> 8. You will know you are successful if the pump flange slides
> forward easily on the bolts and mates to the mounting surface
> of the engine accessory case with no resistance whatsoever.
> Anything else is no bueno -- pull the pump out and start
> again. (The fatal RV crash occurred because the builder
> cranked the bolts down in spite of interference and bent the
> pushrod shaft.)
>
> 9. Once the pump flange sits flat against the engine, hold the
> pump in place with one hand and tighten the bolts on both
> sides with the 5/16 inch allen wrench with the other.
>
> 10. Safety wire the special bolts to each other. (Also a bit
> of an adventure, but this one is left as an exercise for the
> student. ;-) ).
>
> 11. Reconnect in inflow, outflow and overflow lines to the
> pump. Replace lower spark plugs (new gaskets, of course), and
> oil filter. Start engine and do a leak test and fuel pressure
> test.
>
> Hope this helps if you should find yourself needing to replace
> the engine driven pump on your Lycoming. Remember, if you are
> having to force anything, the new pump is not in its correct
> position. Happy flying.
>
> Dan Masys
> RV-10 N104LD
> Tech counselor, EAA chapter 1541
>
> ----------------------------------------------------
>
> In addition to Dan's comments, I would add this: As Dan
> notes, the holes are oblong and it appears designed to tilt
> the pump as you install it under the pushrod. That said, what
> I have had good luck with is this: I have used fine safety
> wire, or you could use dental floss, to run a couple of twists
> around that push rod, and then pull the thread out and tie it
> to the engine case or engine mount snugly. That will hold the
> push rod up. If you follow Dan's guidance, it shouldn't be
> necessary to hold the rod up, but myself I would prefer to
> have as much gap there as possible to ensure the rod gets in
> proper position on top of the lever. Just make sure whatever
> you use is removed completely before you fully seat the pump.
>
> Hopefully Dan's post comes in handy for some of you.
> Tim
>
>
> --
>
> */Phil Perry, /*EAA Lifetime #834284
>
> President, EAA Chapter 59 - Waco, Texas
>
> EAA/The Spirit of Aviation/
>
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|