Oil pressure gauge

[Randy R.]

Re: Oil pressure gauge

The new Melling 55 pumps have a green 78# spring. I installed the spring from the original pump into the replacement pump. Gauge reading is now OK.

[Gerald C.]

Re: Oil pressure gauge

Bob,

I have the same situation on my 63. Can I ask where you got the correct spring and where should I get it?

Jerry

[Joe L.]

Re: Oil pressure gauge

Bob,

I have the same situation on my 63. Can I ask where you got the correct spring and where should I get it?

Jerry

Jerry-----


Both springs remain available from GM to this day for a nominal cost. Part numbers are shown in a post above.

[Peter T.]

Re: Oil pressure gauge

Connecting to old news but. My '66 oil press gauge reads high until the engine warms up and then it drops a tiny bit. So since I have the pan off I am going to change the pressure relief spring. I don't have the pump off yet but it looks like a Melling pp (has USA cast on it on 2 sides, no GM number). Anyway I just ordered the spring, GM 3814903 NOS in the GM bag for $20 from a guy on EBAY who still has 4 left if anyones interested. (No it's not me, my brother or cousin). When you take the pump apart is it obvious how the spring fits in?
Thanks

[Joe L.]

Re: Oil pressure gauge

Connecting to old news but. My '66 oil press gauge reads high until the engine warms up and then it drops a tiny bit. So since I have the pan off I am going to change the pressure relief spring. I don't have the pump off yet but it looks like a Melling pp (has USA cast on it on 2 sides, no GM number). Anyway I just ordered the spring, GM 3814903 NOS in the GM bag for $20 from a guy on EBAY who still has 4 left if anyones interested. (No it's not me, my brother or cousin). When you take the pump apart is it obvious how the spring fits in?
Thanks

Peter------


GM has even more of the GM #3814903 left and the GM LIST price is $4.93.

Changing the spring is easy. First, remove the cover (and oil pick-up) by removing the 4 bolts. Next, push out the pin at the end of the spring bore. Remove the spring. If the valve comes out simply re-insert it. Install new spring. Replace pin. Re-install cover.

Your pump is an aftermarket pump, possibly a Melling. While you have the cover off, check the length of the gears. If the gear length is 1.2", you have a standard volume pump as you should have. If the gear length is 1.5", you have a high volume pump. If so, replace it with a standard volume pump.

[Peter T.]

Re: Oil pressure gauge

Joe,
Took off the oil pump. Metal tag has a few numbers followed by a HV and the gear length is 1 1/2". So I ordered a standard volume Melling pp and new pickup. I'll replace the spring in this with the GM one. There was no gasket where the old one connects and none mentioned in the Chassis Manual but Summit sells a copper one. Is this necessary?

[Duke W.]

Re: Oil pressure gauge

GM didn't install a gasket between the pump and block. As long as the surfaces are flat, there will be a slight leak at that interface, but not enough to affect oil pressure.

Duke

[Peter T.]

Re: Oil pressure gauge

Duke,
Thank you. I blew 4 bucks !!

Pete