oil leak 66 389 GP
 

Hi friends,
need help with my small oil leak maybe a drop or 2 daily on my 389 .
Drip is coming off the bottom of the fuel pump .
I have looked above and can not find any oil on anywhere above the pump.

this happened a few months back and I put new gasket where it mates to engine. it stopped for a while but now is back.
any tips to make sure it works when I do it again.
all advice appreciated.
is this a common leak on 389s?
Allan

Did you use a quality gasket and torque to spec, 15-30ft/lb? Do you have a breather on 1 of the valve covers and is the PCV valve clear to prevent pressure build up?

thanks for response, used felpro gasket. yes I have a new pcv valve to carb vacuum.. did not tore to spec , may have over torqued.

I believe one or both [pump mounting bolts are threaded through to the timing chamber and oil can bleed up the threads. Take out one bolt at a time and clean the threads on the bolt and timing cover. Get some thread sealer and try again.

I think it is just the bolt closest to the engine. They used to come with a special seal washer from the factory if I remember correctly.

thanks, this may be the issue, mine had those washers but I took them out because they were worn/defective from age use. thats when my leak started. I wonder where you could find new original bolts and those special waters.

The older engines/timing covers use 3/8-16 bolts with a 12 point small head. They are called Ferryman head bolts. It's possible the regular head bolts are not seating flat on the pump. Using pipe sealant with Teflon or aviation form a gasket on the bolts should seal that area as mentioned. Also it's possible the pump itself may be leaking oil from wear or poor manufacturer. If you need the correct bolts, PM me after you verify the thread size, 3/8 vs 5/16 and I will send you a couple for shipping cost.

Here is a pic of the correct bolt style.

do you also have the special washers? I will try to verify bolt size

yes mine are 3/8-16 no finding the special seal washer

AMK has the washers and bolts.

https://www.amkproducts.com/search-result/?ser=b-14120

https://www.amkproducts.com/search-result/?ser=b-13948

Now just find another $30 in hardware you need...

I honestly didn't realize they used those special sealing washers. So I probably have the bolts, no special washers. a dot of RTV under the head of the bolt with a small diameter washer would almost certainly do the trick.

I found it Summit racing, it has hex head no prob.
will let y'all know if it solved problem.
thanks once again to the best car guys Pontiac rules.
Allan
https://www.summitracing.com/search/...yword=190-1602

Oil leak 66 389 HP
 

Our host offers the sealing washers under p/n N128RW for $ 6 per pair for 3/8 bolts and p/n N128RX for 5/16 bolts for $5 per pair. Catalog shows 3/8 application is 1964-68 and 5/16 application is 1969-77..

thanks for the heads up, I just ordered from Ames. To have extra washers.

Glad to see you ordered from Ames. The ARP 190-1602 is the smaller 5/16" bolts used on the later style timing covers. Good catch.