Mechanical fuel pump oil leak

[LeonBlank]

Good morning!

1963 F100 223 L6

Long story short.
Removed electronic fuel pump installed mechanical pump....new tank....new lines, new filter.

New fuel pump from O'Reilly lasted under 40 miles and refused to push fuel.
Second pump from NAPA runs great but pushes oil from weep hole something fierce.

At idle I have good PCV flow proven at top of valve cover. Could I have pressure at 2-3,000 rpm?

I have 2,000 miles on a complete rebuild.

Thoughts? Besides sticking in a toothpick

 

[DON]

Can’t plug the hole, it’s a vent hole for when the diaphragm moves. Try again with another. Some will tell you to go back to electric

 

[LeonBlank]

This would be my third one. Now this one on the drive home the pivot pin walked out.
Dang it i was trying to have it as close to original as possible. Looks like im digging out the removed electric pump.

They just don't make stuff like they used to

 

[DON]

You could reinstall the electric, plug the hole, leave some tubing— it would look like original

 

[LeonBlank]

You could reinstall the electric, plug the hole, leave some tubing— it would look like original

Thats how the original owner had it lol

 

[drag-200stang]

Thats how the original owner had it lol

He was a learned and smart man. I tried the mechanical and gave it up 50 years ago, never again.
Electric= faster starts, when it sits for a while, especially when you run out of gas.

 

[LeonBlank]

He was a learned and smart man. I tried the mechanical and gave it up 50 years ago, never again.
Electric= faster starts, when it sits for a while, especially when you run out of gas.

"Rolling my eyes" " I know I know" just hoped to get it more original umder the hood. When I first dod the mechanical pump I loved it. Quiet and fired right up. It gets driven every few days so empty carb was not common.
Same reason I argued with my wife that I wanted to fix the am radio instead of the retro sound she wanted me to get.

 

[DON]

Same reason I argued with my wife that I wanted to fix the am radio instead of the retro sound she wanted me to get.

Look on eBay, you can find better quality units that will fit in the original hole. Retro sound stuff is cheap quality, have been disappointed with my unit

 

[chad]

carter st/strip is a mod on our archive.

Classic Inlines

I’ve hada delphi 15 yrs that’s fine...

 

[manglass]

Unless you need the booster for vacuum wipers, a Carter M3553 should fill the bill and last longer than the drive home.

Lou Manglass

 

[chad]

i think that IS the Street / Strip mentioned in post #9.
U will hafta save the arm off the other, pull the pin, use it on this ‘carter’.
Again, C write up in Archive~

 

[LeonBlank]

For experiment sake.... I plugged the weep hole as the 3rd pump sprayed oil onto the oil filter. At high RPM oil seeps from the pivot pin location as well as the diaphragm area. I am going to clean up, tighten the screws and see what happens on the drive home. I will order the Carter M3553 if I still have the issue and go from there. I have confirmed vacuum at the top of the valve cover so I know I don't have blow by crankcase pressure.

Thank you.

Some lunch break testing. At high RPM looks like the seal on the pump shaft allows oil to get to the diaphragm. When the diaphragm goes up it forces the oil out pf the weep hole or the diaphragm gasket which is easier path than back up the shaft seal.

 

[chad]

the carter flows a lill higher (see part of name “strip”) thn my delphi (3 - 7 psi) . Dont 4get to save the arm off correct prt # mechanical FP.

Classic Inlines - Carter Fuel Pump Modification

 

[LeonBlank]

The carter i have ordered has the same short arm my current pump has. Should be good there.

 

[Adriatic Machine]

Following! I’ve got the same issue. I couldn’t figure out where the oil was coming from until I wrapped the pump in foil and cleaned the area. Now it’s just dripping down on the control arm. I’ve had good results with Carter products so I’ll likely order the M3553 as mentioned above.

 

[LeonBlank]

New pump should be in the end of the week. I will report back with all results.

If this fails...that will be my last trial before going back to a electric pump.

 

[LeonBlank]

I have updates.

I have installed the Carter pump M3553. I purchased it from the jungle website for under $50 which is nice. Gave it a shake down run last night and looks good so far.
I took apart the NAPA pump (B0086P) I found a seal that was torn. Sure looks like this is damaged at the point of assembly. The seal faces down (like a funnel) the rip allows hot oil to leak past and as soon as the diaphragm pushes up at high RPM (2,500+) it pushes against the seal closing it off and forcing oil out the weep hole......or if you plugged it with a toothpick it forces it out the diaphragm seal. That rip is formed when the seal is pushed over the shaft top as its flat, wide, and has a horrible bur on the back side of the stamping. The seal moves up and down that shaft when running but only on the smooth portion and should not cause that to rip as it's soaking in oil.

I am going to order a new NAPA pump and inspect to see how a brand new one looks for science. I have been through 4-5 pumps on one tank of gas so I am pretty sure my findings.

I will post those findings next week sometime.

-Andrew

 

[Adriatic Machine]

Awesome detective work, or scientist? Forensic mechanic? I’ll be going with the Carter

 

[LeonBlank]

I found that all the things I struggle with, I google and find pages and pages of threads with the exact situation but not 1 resolution post or how they actually fixed it. I try my hardest to provide a detailed answer for future searchers!