MM ZAU oil pressure

1031D · Apr 9, 2009

I have a 1952 ZAU that I recently rebuilt but never touched the oil pump because it worked fine before, and now, it holds great oil pressure until it's good and warm and then it just drops off. I tried readjusting the screw on the side of the pump and it helped some, but when it's warm at idle the gauge reads 0! I do have a reproduction gauge in it but it is a genuine Rochester gauge. Should I pull that pressure screw out and maybe clean the housing or replace something? I might also add that the engine has about 100+ hours on it and it did not have this problem until last fall.

Alan K · Apr 10, 2009

It might be a good idea to unhook the gauge by the oil pump and screw in a different oil gauge to check if its the gauge or not.

1031D · Apr 10, 2009

Okay, I tried a different gauge, and same thing, and I unhooked the line and it shot like a garden hose. I then drove it into the shop and drained the crankcase. When I pulled the plug hot burnt smelling oil shot out like water and filled a 3 gallon pail!!!!! Is it possible that the hydraulics did this? I have noticed that I had to refill the reservoir again and it was defiantly not water or gas that came out. Do you think my pump seal went bad or did that reservoir vent do that?

Anonymous-0 · Apr 12, 2009

i had the same thing on my ZBE , and it was the hyd pump seal , filled crank case and thinned the oil !!!

MM ZAU oil pressure

1031D

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Alan K

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1031D

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Anonymous-0

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