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Mechanical Fuel pump Replacement

Plummit

Well Known Member
In the process of replacing my LW15473 engine-driven fuel pump with cooling shroud. Any recommendation on a gasket sealant to use? I would like the gasket to remain in place on the pump as it's a Witch with a capital "B" to get the pump, shroud, bolts and gasket all in there while insuring the pin stays up at the same time....

-Marc
 
EZ Turn Fuel Lube is an excellent gasket conditioner and really sticky!
A little goes a long long way. Buy a tube and you will probably have it for life.
Always trust Paul but was introduced to EZ Turn many years ago so that’s what I use. Done several fuel pumps with it, no issues.
“I put that _hit on everything” ;)
 
LOL

“I put that _hit on everything” ;)

That cracked me up!
+1
I use it primarily as a gasket release agent for the future removal of the component.
Saves the effort of removing an old, stubborn baked-on gasket.
 
Got 'er done this week. Used Permatex #2 to stick the gasket to the pump. After wasting an hour trying to get the drive pin lassoed with some lacing string, I was able to just install the pump! Didn't use anything to hold the pin up, just made sure the pin wasn't being pushed down by the eccentric and installed the pump.

-Marc
 
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I just did this same replacement on my bird.... how in the world do you get the safety wire back on? I haven't cracked that nut yet.
 
I just did this same replacement on my bird.... how in the world do you get the safety wire back on? I haven't cracked that nut yet.

Good question! Mine didn't have safety wire, and neither did a late model Cessna 172 with an IO-360 fuel-injected L2A which appeared to have the same pump.

-Marc
 
I just did this same replacement on my bird.... how in the world do you get the safety wire back on? I haven't cracked that nut yet.

A) Take the left Mag. Yup, you CAN get the safety wire on without doing that, but you might actually save time overall by removing and replacing (and re-timing) the mag….

B) Use a Safe-T-Cable ! :)
 
Marc,

Come over to my hanger at Eagle Alley, I have the DMC Safety Cable that Paul is talking about. Quick job on the fuel pump.
 
I had to Google that one .... $450 dollars...

YIKES

I might have to start drawing something I I can 3d print lol....

A) Take the left Mag. Yup, you CAN get the safety wire on without doing that, but you might actually save time overall by removing and replacing (and re-timing) the mag….

B) Use a Safe-T-Cable ! :)
 
Marc,

Come over to my hanger at Eagle Alley, I have the DMC Safety Cable that Paul is talking about. Quick job on the fuel pump.

Thanks Scott, I'll keep that in mind if I have problems getting wire on those 2 bolts. I did my prop with .041 so I feel pretty experienced now! :)

-Marc
 
That’s cheating, real mechanics don’t use fancy tools or wear gloves (no gloves when applying pro seal either) :eek:

So I can send you my Dynavibe Classic and you’ll send me your incredibly cool prop balancer in trade? ;)
 
3-D Printed Part - Steve Melton Where Are You?

Here's a "gadget" I made to solve the problem of holding up the fuel pump "rod" when installing a new fuel pump - mostly when the engine is in place & access is restricted. Although mine is made of out steel and silver brazed together, it would seem to be a perfect project for the 3-D printing world. You may not use it very many times in your capacity as "Maintenance Officer", but sometimes once is enough to make you a believer! It would seem that the printing process would get the unit cost down to a reasonable level?

The way is works is, the tool looks like an upside down cross, with a yoke at the top that "captures" the elastic retaining band (or whatever you choose). The "cross arms" on the handle position the tool on the fuel pump mounting face so the tips of the yoke are in line with the center of the fuel pump rod when the cross arms contact the mounting face. Put the retaining band on the tool as shown (a big enough "loop" to ensure going past the fuel pump rod), and insert the tool far enough below the end of the rod to insure "capture". Once the tool is inserted and the cross arms contact the mounting face, slide the tool up until it contacts the upper limit of the opening in the mounting face. Then, "draw" back the retaining band until you feel it putting pressure on the rod. If you are using an elastic band (I do), you can stretch it enough to find something above it to attach it to, to insure enough tension on the band so that when the rod is pushed up, by reaching your finger into the mounting cavity, the rod will remain "retracted". Then it is simply a matter of installing the pump & gasket with the 2 1/4-20 NC socket screws provided. Once the socket screws are in place, and you are assured the fuel pump arm and rod are fixed in their correct orientation, simply cut the retaining band and pull it free.

Before I forget - the gray box/rod shown is an exact simulation of the fuel pump mounting face & rod on the accessory case.

I know there people out there that swear by putting a dab of heavy grease on the rod to hold it in place - but unless you've done that your whole (maintenance) life and have developed a proficiency for doing so, it is not that easy - especially in the close confines of an installed engine. Ask me how I know!

If anyone out there wants to "mess" with this as a 3-D printer project, I'll be glad to send you the particulars of my prototype.

YMMV - but this does work!

HFS
 

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I did mine with common string.... it has just enough drag to keep the rod from sliding down, but slides easily out between the gasket and the flange.

BUT, it was a PITA to get the string around the rod. You have a great tool here. I would have gladly paid a reasonable amount for it.

You should contact the fuel pump people and see if they would want include it with their pump...$$
 
Gonna piggyback on this thread as I too have a fuel pump to install, only my engine is off the plane right now. How exactly is that pin supposed to be oriented? Does it just need to be on top of the arm?

Is it typical to use sealant on the paper gasket and/or bolts? Before this thread I was fully prepared to just bolt it on and go.
 
If anyone out there wants to "mess" with this as a 3-D printer project, I'll be glad to send you the particulars of my prototype.

If you send me the key dimensions, I might get bored enough to model it up in Sketchup and print one off. Maybe take a picture of it laying on a piece of graph paper with a ruler?

Is the string elastic, rubber band, or just string?

I have used the heavy grease trick, and stabbed it in before the pin slowly fell down. Not fun, took multiple attempts and more grease than you think…
 
Gonna piggyback on this thread as I too have a fuel pump to install, only my engine is off the plane right now. How exactly is that pin supposed to be oriented? Does it just need to be on top of the arm?

Is it typical to use sealant on the paper gasket and/or bolts? Before this thread I was fully prepared to just bolt it on and go.

With the old pump removed and the surface cleaned on the case, reach in with your finger and push up on the rod. Rotate the motor by hand until the rod is as far up as possible. That is where you need it to be held as you install the new pump.

Some string can be placed around the rod. I used a loop of string and a small bungie cord hooked to the string to hold the rod. Once the pump is close to seating, just cut the string and pull it out.

I used a little Permatex to hold the gasket in place. And put some on the bolt threads... the case is drilled through and you can get an oil leak out of the threads. Start the bolt on the right first, just enough to hold the pump parallel. The left side will be a little lower. Rotate the pump cw and start the left bolt. At this point, the rod will be pushing on the pump arm. Push on the pump and it should rebound. Don't force the pump in place. If the mounting surfaces are not kept parallel, the rod can be pushed aside by the arm.

A T handle allen wrench works great, just run the bolts in evenly. https://youtu.be/1FxIZdDxKKM I had no problem using the non ball end.
 
+1 on gasman's instructions :)

Having had the great pleasure of replacing my pump on a certain field in UT a few months ago, I can vouch on the method as described. And wished Vlad or John would have had had a Safe-T-cable, mine was at home ;)
 
Yes, the pin just sits on top of the arm.

I had my left mag off the plane at the time I reinstalled my fuel pump. You can reach in thru the mag hole and hold the pin up with your finger, then easily slide the fuel pump on and install the bolts. And as Paul said, it’s much easier to safety wire the pump with the mag off.

Gonna piggyback on this thread as I too have a fuel pump to install, only my engine is off the plane right now. How exactly is that pin supposed to be oriented? Does it just need to be on top of the arm?

Is it typical to use sealant on the paper gasket and/or bolts? Before this thread I was fully prepared to just bolt it on and go.
 
I thought about pulling the mag but in the end, it worked out OK. I really believe that you don't need to hold the pin up while installing the pump. You should rotate the engine around until the pin is at the highest point as you don't want pressure downwards on it when you slide the pump in.

The RV-10 is a whole different order of difficulty as the oil cooler is mounted to the firewall - right in the way!

-Marc
 
Did your pin stay in the up position?

I’ve installed several fuel pumps, and have always rotated the engine until the pin is at its highest point. Even then (at least in my case), the pin doesn’t stay in that position, it drops down the shaft. I’ve always had to hold it up to slide the pump in.

I thought about pulling the mag but in the end, it worked out OK. I really believe that you don't need to hold the pin up while installing the pump. You should rotate the engine around until the pin is at the highest point as you don't want pressure downwards on it when you slide the pump in.

-Marc
 
My engine driven fuel pump went out on the ferry flight home after I bought it a few years ago. The A&P at the remote, tiny Iowa airport where I had stopped for fuel came in on a Sunday afternoon to replace it. He ultimately had to use safety wire to hold the pump lever down. After positioning it and getting a couple of turns on all the bolts, he then cut the wire after making sure the arm was underneath the pin. It was frustrating, difficult, tight-quarters work. I’ve been a surgeon for 40 years. I was impressed with his patience and his equanimity.
 
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Getting the pin to stay in position was the easiest part of the job. I pushed it up, and it mostly stayed in place while I moved the pump into position.... really no effort. I did have the mag off while doing this, and it's very easy to hold the pin in place through the mag hole if necessary. all with my (ungloved) fingers. I suspect that if the pin were so loose that it wouldn't stay up long enough, a tiny amount of heavy grease on the shaft would make it stick long enough for the task at hand.
 
Did your pin stay in the up position?

I’ve installed several fuel pumps, and have always rotated the engine until the pin is at its highest point Even then (at least in my case), the pin doesn’t stay in that position, it drops down the shaft. I’ve always had to hold it up to slide the pump in.

And my pin wouldn't stay up either. It would start sliding down almost immediately. Finally I just tried installing the pump and it dropped right in. There is not a lot of movement in that pin, and I feel that if you just install the fuel pump with the lever at a little downward angle you will be fine. At least that's how my Barrett IO540 worked. YMMV

-Marc
 
I did mine with common string.... it has just enough drag to keep the rod from sliding down, but slides easily out between the gasket and the flange.

BUT, it was a PITA to get the string around the rod. You have a great tool here. I would have gladly paid a reasonable amount for it.

You should contact the fuel pump people and see if they would want include it with their pump...$$

I use the waxed tie cord, typically used for wire bundles. The waxed nature makes it a bit stiff and formable enabling wrapping the cord around the pin. It is also flat and very strong, ensuring easy removal and never a doubt of leaving pieces inside the engine.
 
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