1930 Buick Model 60

[snosurf]

I have had a problem with oil pressure so I rebuilt the pump to correct specs and am now pre lubing the engine to see if there are any oil leaks in the lower engine or valve train, etc....  The oil pump is out and I am hooking into where the oil pump meets the pipe system that feeds the mains, rods and the upper engine.  There is what looks like an oil pressure release valve there.  When i send the oil in at a bout 30lbs pressure, oil squirts out of either side of the relief valve.  Has anyone had any experience with this?  The oil pan is off the engine, of course.

 

Thanks - Piers MacDonald

[Oregon Desert model 45]

Open up the valve and check the spring - it probably needs replacing. The maintenance manual might provide some guidance for spring compression rate in selecting a new spring.  My 1924 pressure relief valve spring was rusted and would have resulted in no oil pressure if I did not replace it. 

[Roger Barrett]

The relief valve should be set higher than 30 lbs. You may have to shim up the spring. Also watch for leaks in the oil manifold joints. You should be able to hold 40 psi from an external oil source easily. Here’s another tip. The original oil filter had a fitting with an orifice to limit oil flow to the rocker arms and valves. If that is not in place the engine will dump off pressure into the valve cover. 

[snosurf]

 

Thanks very much.  It appears that the plunger is stuck.  I'll take it apart and see if I can get a spring that will work.  There is no mention of the relief valve in the manual.  I have an oil filter from Bob's in CA.  I rebuilt the oil pump with his gears and they fit very well.

 

Thanks again- 

[DonMicheletti]

One of the very important items is the clearance between the gears and the pump cover. Check to be sure it is within specification using plastigage if you have not already done it..

[snosurf]

Thanks Don.  Had not thought about using plastigage on the cover.  Good idea.  With the new gears I am well within specs on the lash.  Was .019", now .007".  The pressure release valve was stuck with some sludge.  So I think I am on the way!