Hello TC members. Our 71 SS 454 has developed a really wierd oil/fuel leak at the fuel pump/mount area. If you are just driving around normal surface street speeds and staying off it; only a very small if any at all amount of what appears to be oil puddles on top of the Edelbrock fuel pump.If we are on it hard or "spirited" driving then a whole mess of what appears to be oil puddles on top and below pump and even drips off it(Fuel pump that is) after you shut it off.It must leak pretty good at higher speeds cause the fan will blow it back all over the starter and our nice clean frame. The dipstick and oil fillers are not leaking either and the engine has no other oil/coolant/fuel leaks of any kind.I have the front suspension off right now to redetail and we are going back to the NOS fuel pump and metal line at this time to cure it.
Smelling this what appears to be oil also has a gasoline smell as well just not very pronounce.
A search resulted in SBC info that mentioned a front mounting boss near the timing cover that needs to have a short bolt in it to stop oil leaks? This apply to BBC's as well? Mine dosent appear to be leaking from this area so i dont think this is it. Any ideas from the great minds out there?

I also did some research on these Edelbrock performer series pumps and it appears at first glance that these pumps have a sticking relief valve of sorts that cause some to build up pressure and burst or split the rubber fuel line at the connection point and it appears that this is what has happened here with mine(It leaks fuel where the hose clamp holds line to barbed fitting). I still however dont know where the oil is coming from. Some might be coming from that angled pipe plug directly underneath the pump maybe do to seapage? It dosen't appear to be leaking from the gasket area where the pump mates to the block. It looks like it is leaking oil from the pump itself around the sides at those gaskets. Could oil get into the pump itself and gas get back into the motor?-this sound right? As stated previously the oil will puddle on top of the pump.
http://lh3.googleusercontent.com/kdOnD_bnGois4jLDsobDLuIYlEEl2ehqqbcgQaFNnWNRuiPmaP r64UqYST5_lRUUc3uKGidAa3-TlVwY1nqWx2kWe0Bbed0xa8Mj7gk9o86AlslaoO515JtNIuTKQ WF_sg8Z__KffyLfaZ8oZaMyw5sTeY6HqsoOy-Yioq1jvOU4oflwD53AUyzkEob-mx9opB-nkw880fxX0h6P1Do (http://www.google.com/products?hl=en&q=edelbrock+fuel+pump&um=1&ie=UTF-8&ei=-NZFTIHuD4b0swO758WkAg&sa=X&oi=product_result_group&ct=image&resnum=3&ved=0CCsQzAMwAg)

I suspect the pump has failed; you've got a cracked casting or other flaw allowing oil to leak. Defective fuel pump gasket would be the #2 reason for oil leakage, but you're saying that the gasket seems OK.

I'm wondering about oil drain-back from the fuel pump pushrod-pump arm cavity of the block. Perhaps you have a plugged or partially-plugged drainback hole, and the excess oil is finding another way "out".

If the diaphragm ruptures, you can get gasoline pumped into the oil pan, and gasoline can spray out the vent. Marine pumps have the vent plumbed into the air cleaner for that reason--the Coast Guard is very allergic to gasoline fumes in the engine compartment of a boat.

I suspect the pump has failed; you've got a cracked casting or other flaw allowing oil to leak. Defective fuel pump gasket would be the #2 reason for oil leakage, but you're saying that the gasket seems OK.

I'm wondering about oil drain-back from the fuel pump pushrod-pump arm cavity of the block. Perhaps you have a plugged or partially-plugged drainback hole, and the excess oil is finding another way "out".

If the diaphragm ruptures, you can get gasoline pumped into the oil pan, and gasoline can spray out the vent. Marine pumps have the vent plumbed into the air cleaner for that reason--the Coast Guard is very allergic to gasoline fumes in the engine compartment of a boat.Thats what I'm thinking-a defective pump or one thats going bad. Its over a year old but oh well I guess "made in USA" dosent always mean better.If the diaphram ruptured would the motor still idle and run correctly even at WOT?

Marc S

Check and see if the bolt is in the front top hole in the block.

Thats what I'm thinking-a defective pump or one thats going bad. Its over a year old but oh well I guess "made in USA" dosent always mean better.If the diaphram ruptured would the motor still idle and run correctly even at WOT?

Marc S

Mine still idled pretty well with a ruptured diaphragm. As Mike noted though, in the front of the block, by the fuel pump should be two bolts. Look and see if it is coming from the area of the top bolt.

I dont know if the big block has the same bolt hole as the small block, but this fixed my weird leak.

http://www.chevelles.com/forums/showthread.php?t=318668

Check and see if the bolt is in the front top hole in the block.There are indeed the two holes but neither have a short bolt in them and neither appear to have had oil leaking form them but that in itself could be decieving.

Your saying even on a BBC there should be a real short bolt in the top one correct?

Marc S

Yes.

Yes.
Thanks, it's off to the hardware store i go.

Marc S

Get a short bolt - 1/4" to 3/8" will be fine.
You don't want to hit the pump push rod.

There are indeed the two holes but neither have a short bolt in them and neither appear to have had oil leaking form them but that in itself could be decieving.

Your saying even on a BBC there should be a real short bolt in the top one correct?

Marc S
On MY 454, the front motor mount bolt hole by the fuel pump is blind. There is no way oil can leak out like it does on a smallblock.

First Guess: Yours is the same; and installing a bolt there will do nothing positive for you. There's no trace of oil leakage by those bolt holes because...there's no oil leakage by those bolt holes.

On MY 454, the front motor mount bolt hole by the fuel pump is blind. There is no way oil can leak out like it does on a smallblock.

First Guess: Yours is the same; and installing a bolt there will do nothing positive for you. There's no trace of oil leakage by those bolt holes because...there's no oil leakage by those bolt holes.Thats what i thought. I believe the pump is going bad and leaking oil past the pump body gaskets where its sandwiched together(not where pump meets block) as well as leaking gas from where the rubber house is hose clamped to the nippled brass fitting. As stated above I sourced an LS5 pump and metal line so that should solve it hopefully cuz its not leaking gas or oil anywhere else so this has to be it.

I had a similar problem with a little oil on bottom of fuel pump and also alot all over the fuel pump and pass lower control ams and other areas on pass side when I got on it

it ended up being oil leaking from front paas side oil pan gasket a few inches back from the front, took me forever to find the problem because it would only squirt out of there when getting on it pretty good.


put it on my lift with a friend inside to rev it up it shot out like a water pistol all over under high revs. but would not leak at idle

Bill

I had a similar problem with a little oil on bottom of fuel pump and also alot all over the fuel pump and pass lower control ams and other areas on pass side when I got on it

it ended up being oil leaking from front paas side oil pan gasket a few inches back from the front, took me forever to find the problem because it would only squirt out of there when getting on it pretty good.


put it on my lift with a friend inside to rev it up it shot out like a water pistol all over under high revs. but would not leak at idle

Billthats where i looked first but you would think there would be oil residue all over form leaking/squirting out?

Marc S

Ya, I had oil all over from squirting and from blowing back while driving but mostly drips coming off of fuel pump, I could not tell it was from the oil pan untill I cleaned everything and put it up on my lift with someone inside car revving it up, then saw it plain as day squiring onto fuel pump


Bill

On my BB I had an Edelbrock fuel pump that started leaking oil. I snugged up all the screws at bottom of pump. That worked for awhile, than it started leaking again so I tightened the screws some more. That ruined the pump, it started leaking bad to where it would leave a small puddle where ever I parked. I removed the pump for inspection and saw that by tightening the screws to tight, it warped the area the screws screw into. Replaced with a Holley fuel pump and I'm happy again.

On my BB I had an Edelbrock fuel pump that started leaking oil. I snugged up all the screws at bottom of pump. That worked for awhile, than it started leaking again so I tightened the screws some more. That ruined the pump, it started leaking bad to where it would leave a small puddle where ever I parked. I removed the pump for inspection and saw that by tightening the screws to tight, it warped the area the screws screw into. Replaced with a Holley fuel pump and I'm happy again.Changing it out this weekend.:thumbsup:

Well, all is good-no leaks at all now-bad pump.

Marc S