Possible fuel pump leak

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Question Authority - 04 Oct 2006 13:32 GMT

Hello Folks.
'81 Pontiac 305 V8, H code engine

Mechanical fuel pump on side of engine has very slight gas residue -
not dripping, barely discernible - on upper hemisphere of pump.
No gas evident on oil dipstick.

Is there a weep / relief hole in that area, to drain pump if diaphragm
leaks ?

... or is such miniscule gas residue inconsequential?

I've had a fuel pump die before ( '72 Buick Sylark / 350 ), but that
was noticeable by gas dripping.

Otherwise the Pontiac runs good .. just turned over 90,000 Km. ( had
55,000 when I bought it a couple of years ago ).

Unlike the Buick Skylark, I believe the Pontiac fuel pump is driven by
a pushrod (?) I've read that it can be held in place by grease during
reassembly.
Any suggestions or advice re: installing such a pump? ( if it is
necessary now ). Please reply to NG

Thanks, -JS

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Mike Romain - 04 Oct 2006 15:41 GMT

That would imply the gas line fitting is leaking slightly.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
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> Hello Folks.
> '81 Pontiac 305 V8, H code engine
[quoted text clipped - 21 lines]
>
> Thanks, -JS

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Question Authority - 04 Oct 2006 22:57 GMT

Hello Mike.

The gas line fitting is dry.
The slight gas residue is higher up, on upper part of dome of pump, on
left side -- away from line fitting.

-JS

>That would imply the gas line fitting is leaking slightly.
>
[quoted text clipped - 30 lines]
>>
>> Thanks, -JS

Reply to this Message

Mike Romain - 05 Oct 2006 18:42 GMT

Oil drip from up above?

Mike

> Hello Mike.
>
[quoted text clipped - 38 lines]
> >>
> >> Thanks, -JS

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Question Authority - 06 Oct 2006 13:08 GMT

No, it smells like gas;
but amount is very small.
I think it may be the beginning of the end of fuel pump.

Is there some kind of relief hole in upper dome area of pump
to drain gas in case of diaphragm rupture ?

-JS

>Oil drip from up above?
>
[quoted text clipped - 42 lines]
>> >>
>> >> Thanks, -JS

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Mike Romain - 06 Oct 2006 14:31 GMT

None that I know of. When the diaphragm goes, the engine gets gas in
the oil.

Could be the cast has a pinhole in it. New pumps are cheap.

Mike

> No, it smells like gas;
> but amount is very small.
[quoted text clipped - 51 lines]
> >> >>
> >> >> Thanks, -JS

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