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-   -   Replacing Engine Fuel Pump (https://vansairforce.net/community/showthread.php?t=15148)

Hartstoc 02-18-2019 12:29 PM

Quote:

Originally Posted by AlexPeterson (Post 104637)
Is it just me, or are these engine mounted fuel pumps a real PITA to install? I have rotated the engine until the plunger is as far up as it goes. I can get the pump in all the way, as long as it is tilted a little bit. So far, so good. The problem arises when I try to get the socket head cap screw started. Because of interference between the screw head and the pump casting, I'm not able to get it properly aligned for starting the threads. The only way to get alignment of the screw is to pull back the fuel pump a little, which causes the lever to pop up above the plunger. AARRGG.

Any tricks would be appreciated. I have glued the gasket to the pump, so that "trick" is already used.

Thanks!

Mine was mounted with cap screws with allen-wrench socket- heads, and they are drilled for safety wire. I?ve permanently removed my engine driven pump so no longer need them and would be happy to mail them to you unless you have solved the problem by now. Just have to make sure I can get shorter bolts that will work to secure the cover I?m bolting onto the mount pad.- Otis

scsmith 07-15-2020 08:28 PM

This is a great thread - we need to keep it alive for those that come after us.

I still have not won this battle yet. I went out and tried the grease trick with the stickiest grease I could find. No joy. Doesn't help that it is 95F here. Maybe if it were colder.

Anyway, the waxed string/safety wire trick is brilliant. I will do that tomorrow.

It would make life much easier to shorten the screws, BUT the amount of thread engagement into the case would be potentially inadequate. It might be fine to take 3/16" off the screws, but it might not. I won't do it.

Knowing that you can see in through the left mag hole is encouraging. It means I have to re-time my Light Speed hall sensor afterward, but that is a small price to pay to be SURE the lever is properly engaged on the plunger.

N184DA 07-15-2020 08:43 PM

Having that left mag removed also allows you to route the string through the mag access, rather than slipping it between the pump and flange.

The way I did it was to basically tie the string off at one of the engine mount tubes, nice and tight, through the mag hole. Left it that way until the pump was in and the bolts were tight.

And you are correct, having the mag out is a small price to pay for knowing that the pump arm/pin are seated correctly.
And as an added bonus, makes the safety wire a little easier to install.

scsmith 07-15-2020 09:51 PM

Quote:

Originally Posted by N184DA (Post 1446774)
Having that left mag removed also allows you to route the string through the mag access, rather than slipping it between the pump and flange.

The way I did it was to basically tie the string off at one of the engine mount tubes, nice and tight, through the mag hole. Left it that way until the pump was in and the bolts were tight.

And you are correct, having the mag out is a small price to pay for knowing that the pump arm/pin are seated correctly.
And as an added bonus, makes the safety wire a little easier to install.

Another time when I wish the forum had a 'like' button. Thanks.

digidocs 07-16-2020 01:25 PM

I talked to Tempest about installing the pump and they claim that you can actually reach in the L mag hole and hold the plunger up with your hand (where it contacts the camshaft). Not verified, but a good source...

N184DA 07-16-2020 01:29 PM

That is true,,
But I found I needed both hands to manipulate the pump, to orient the holes,, and to start the bolts that do not align when the pump is square on the mounting flange.

scsmith 07-16-2020 05:10 PM

Quote:

Originally Posted by digidocs (Post 1446930)
I talked to Tempest about installing the pump and they claim that you can actually reach in the L mag hole and hold the plunger up with your hand (where it contacts the camshaft). Not verified, but a good source...

A great tip for those three-armed mechanics.:rolleyes:

WAustin 07-17-2020 05:43 PM

Engine Fuel Pump Replacement Hints
 
Hi All

This was sent to members of our chapter of the Sports Aircraft Association of Australia (SAAA). I didnt go through all seven pages of replies, so maybe this has already been posted.

Link is to another forum that has hints on replacing the engine driven fuel pump.

Here it is: https://www.matronics.com/forums/vie...php?t=16775207

Hope that helps someone.

Cheers

Wayne

BruceW 09-01-2020 12:22 PM

Used the safety wire trick for keeping the plunger up. Got it on the second try. Really had to tension the wire to keep the plunger up.
Great use of this forum.
Thanks to all.

gasman 09-01-2020 10:11 PM

Better off to use regular string instead of wire. String has way more drag and will hold the plunger in place with far less pressure.


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