rebuilding early fuel pump

[67azcruizr]

donor was an aftermarket (I believe the only ones available now), but is manufactured by the same as OEM. brand new these pumps should run no more than $80 probably cheaper at your local parts store


these are just some shots of the early pump broken down

 

[67azcruizr]

first thing to do was to straighten and tighten up the hand lever. the flip side of the rivet was set on the flat end of my vice. first I expanded the hole of the rivet to tighten up the I.D./O.D., then a flat punch was used to tighten up any side motion

straighten out the rod and it was nice and smooth

 

[67azcruizr]

next was to separate the inner diaphragm. I did this by filing down the rivet head, then driving out the shaft of the rivet


I'll get into tapping the original shaft for re-use later

 

[67azcruizr]

next step was to remove the check valves. the newer pump has 4 check valves, 2 of them are a snap to get out. the other 2 take a little more finesse

I drilled out the aluminum where the check valves were stamped in, then simply drove out from the opposing side. a 9mm socket worked well on 2 of them

 

[67azcruizr]

the next 3 pictures are just comparisons with the early pump along side of the later pump, both in a broken down state

both diaphragms as well as the check valves look completely interchangeable. this could give you a completely rebuilt fuel pump without the need to start manufacturing/making any parts from scratch

the only thing I've yet to have done is to take the shaft over to my buddy's house and have him mill and tap it so that I can screw the refurbished inner diaphragm back together

 

[67azcruizr]

this is just some shots of the covers and a close up of the shaft that will be getting milled and tapped

 

[IDave]

Sweet. I've had mine apart, too, but I didn't tighten up the hand lever like you did. I'll have to try that. It seems to be leaking a little oil from that rivet.

 

[destin]

Nice man

Thanks for the photos and the bit about tightening the hand primer lever!

 

[foxfab]

very cool

 

[Kief]

Well? do you have problems with the pivot shaft leaking oil?

 

[67azcruizr]

no.....................do you?

I am being serious with this question, .................. it could be other issues

 

[Kief]

I've had old pumps that worked but the shaft leaked oil due to wear.. That was a while ago, now I think I'd try to put in a larger shaft- its been a while since I've tinkered with an F motor

 

[67azcruizr]

while the idea of a hand primer is very cool, under 99% of the situations, the choke should do the job. excessive use of the hand primer would be the only reason I see the shaft/housing receiving enough wear to allow beyond normal oil seepage


my initial thought was poor PCV or alot of blowby with high mileage

 

[Kief]

while the idea of a hand primer is very cool, under 99% of the situations, the choke should do the job. excessive use of the hand primer would be the only reason I see the shaft/housing receiving enough wear to allow beyond normal oil seepage


my initial thought was poor PCV or alot of blowby with high mileage

High mileage and blowby for sure.

 

[Aussie 25]

Sean, That very good info and the pickies say it all. What size thread did you tap in the sharft?

 

[nuclearlemon]

did you ever get the shaft milled and tapped? i'm working on my spare now. here are my step by step disassembly pics. the bit i used is marked phillips #2, but made in taiwan, so that might explain why the bit fit like a glove. i've used a screw from the same set for the oil pump cover on my 80 and had the same excellent fit, so might be close to japanese specs

 

[nuclearlemon]

next set of pics . i got the plate with the diaphram to pop up by turning it counter clockwise. it came loose from one spot, and popped up a little like pic 4, then more turning got it out of the last plate in pic 5. with the exception of this lower diaphram, all of the parts are in good condition even thought it appears something is growing on the housing

 

[nuclearlemon]

pics showing the actuation of the pump lever by working the primer and of the shaft for the lower diaphram

 

[nuclearlemon]

and the valves. there is a small paper type gasket on each one . i'll post more pics after the parts have been cleaned up.

 

[67azcruizr]

I can't remember the milling/tap size, but the metal is soft.

Both Permatex and Locktite make a thread sealant that resists fuels of all sorts including high pressure hydraulics