40727 Fuel Pump

[L78steve]

I have an oil mess in the fuel pump area and cannot locate any obvious locations other than the pump itself.
The crimp seems tight,any ideas?
Its an AC 40727 with the AC cast onto the body.

[WILMASBOYL78]

If you have another pump...clean the area good..and replace and see what you get. Maybe the internals are shot...that could mean gas in the oil...do a sniff test on the dipstick.

-wilma

[L78steve]

Hi, Wilma.
No gas in the oil. I was going to simply change the pump but the AC logo on the body versions are NLA. Only 200 miles on this one but it must have been sitting around for a while.
I guess I'll pop a cheapie on there and see.

[firstgenaddict]

I know that Dave Beem had his original LS6 fuel pump restored. If I am not mistaken they put vitol pump diaphrams in them so the ethanol will not eat them away.

[HawkX66]

I have an oil mess in the fuel pump area and cannot locate any obvious locations other than the pump itself.
The crimp seems tight,any ideas?
Its an AC 40727 with the AC cast onto the body.
How is the pipe plug seal for the fuel pump pushrod access hole?

[mockingbird812]

How is the pipe plug seal for the fuel pump pushrod access hole?


Bingo! definitely on the suspicious list!

[L78steve]

Hmmm. I'll check that.

[L78steve]

Its not the plug.

[DW31S]

I hate to sound like a buffoon, but are you certain the oil isn't running down out of the valve cover? I've seen people drop oil pans, yank engines, etc. to "fix" a rear main that was never leaking at all; merely oil coming from the back of the valve cover.

[L78steve]

Positive not from anywhere obvious. Seems to be from the pump itself. But I've never seen a failure like this. Only a gas leak type failure.
Slow drive around the block nothing. Take it out on the highway and I have a mess.
I also checked the vent system,all good.

[L78steve]

I've never cut one of these pumps apart. There are the 2 little holes in the cast part above the crimp that I assume are there to allow the gas to leak out in the event of a diaphragm failure and to prevent the fuel from reaching the lube oil.

[L78steve]

Turns out it was the fuel pump leaking oil from the gasket. Oil was leaking into the fastener area due to the correct fuel pump bolts from a popular supplier were a tad too long and bottoming in the blind tapped holes.
Replaced the gasket with some anaerobic sealer and removed a bit from the bolt length and all seems fine.

[mockingbird812]

Well that is good news!:biggthumpup:

[earntaz]

Turns out it was the fuel pump leaking oil from the gasket. Oil was leaking into the fastener area due to the correct fuel pump bolts from a popular supplier were a tad too long and bottoming in the blind tapped holes.
Replaced the gasket with some anaerobic sealer and removed a bit from the bolt length and all seems fine.

Maybe small block bolts? They are longer than the BB bolt because of the adapter plate used on the SBC ... TAZ

[L78steve]

Do the small block bolts have the captive lock washer and 7/16 hex heads?

[earntaz]

I've seen them both ways. But OEM bolts have 7/16" heads and do not have captured lock-washers that I can remember ... TAZ