AMC 401 Oil pressure problems.

KarlVP · Jan 31, 2008

Does anyone have a part number for an Oil Pressure Relief valve SPRING. For a 401?

I have heard rumors that there is a "high strength" or "High pressure" spring and that is the one I am looking for, if there is such a beast.

TreeClimber · Jan 31, 2008

Karl.

I've got the factory manual at home for 1975 and 1979 AMC. I can check tonight.

T

GaryTJ · Jan 31, 2008

.030 washer.

KarlVP · Jan 31, 2008

TreeClimber said:
Karl.

I've got the factory manual at home for 1975 and 1979 AMC. I can check tonight.

T

I have the FSM for the 1974 line of Jeep's but it doesn't list the part number. It does have the part number for the 6 cylinder, but nothing for a V-8.

I know the spring is supposed to be tensioned for 75psi. The ones I found are for 60 and 70 psi. Searching the internet, I came across the fabled "high pressure" spring. Don't know if it really exists though.

KarlVP · Jan 31, 2008

After talking with some folks at Melling. They think the main bearings are aboot to make poop.

The symptoms are:

Truck starts fine. Mechanical gauge reads 40 to 60 psi. Once it warms up, the psi drops to around 20. But if you rev it up, it does hop up to 60 or so.

After an extended driving trip, the psi hovers around 20, and shoots up when you step on the gas. But when you come to a stop, at idle the pressure drops to about 5. Put it in neutral and rev it up, and it won't climb past 25 or 30.

Running straigt 30W oil.