mech fuel pump leak oil?

[Dylan86]

Finally got my truck road legal, took her for a long drive the other day, opened up the hood to find a leak of engine oil on the front mech pump side of the block. i also found some coolant. it is a brand new engine. the coolant was from the lower rad hose, so i replaced it, thats all good now. i installed new gaskets for the fuel pump, cleaned it all off and went for another spin, still leaking, but i cant replicate it when in the shop.... the only thing that makes sense is that the fuel pump is leaking oil out the body or something? is that possible? anyone seen something like this? any help would be great.

[ray_mcavoy]

On a lot of blocks there are two threaded holes on the front over near the fuel pump area. One of them is open into the fuel pump pushrod bore and can be a source of the type of leak you're experiencing.

To fix it, simply put a 3/8"-16 bolt in that hole with some thread sealer. Use a short bolt (only about 1/2" to 3/4" long) so it doesn't go in deep enough to hit the fuel pump pushrod.

[wraprail]

I agree with ^ Ray 100% and on a new motor for sure. It could also be the fuel pump itself. There is a hole in side of the pump ( weep hole?) and mine was dumping oil out this hole. Pull it off and turn it upside down. If oil comes out that hole replace it.
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[motornut]

Originally Posted by wraprail

I agree with ^ Ray 100% and on a new motor for sure. It could also be the fuel pump itself. There is a hole in side of the pump ( weep hole?) and mine was dumping oil out this hole. Pull it off and turn it upside down. If oil comes out that hole replace it.
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seen the pump go like that too

[Hubscrub]

Originally Posted by ray_mcavoy

On a lot of blocks there are two threaded holes on the front over near the fuel pump area. One of them is open into the fuel pump pushrod bore and can be a source of the type of leak you're experiencing.

To fix it, simply put a 3/8"-16 bolt in that hole with some thread sealer. Use a short bolt (only about 1/2" to 3/4" long) so it doesn't go in deep enough to hit the fuel pump pushrod.

good chance this is it, easy to check and fix.

[68gmc780]

Mechanical pumps can leak oil externally,fuel externally and internally.Used to see it all the time in the 80's when I started wrenching.

[Dylan86]

hey thanks everyone, that bolt missing is exactly what it was! found this picture after all you said, to help anyone else whos having this issue.

[68gmc780]

Oh yeah! Now i remember that hole! It can be used (very gently) to put a longer bolt in to lock the fuel pump rod in place when you change the fuel pump.Usually it is covered by brackets and other obstructions so that it becomes useless for that procedure.

[Dylan86]

Ok i noticed at idle that hole is sucking allot of air in. when i put the bolt in the pump gets really noisy? is this ok? it shouldnt be this loud?