marco383

Not doing any HPDEs this year (long story), so I use my 3 quart Accusump mainly for prelubing the engine after several weeks of garage duty. After refilling on startup, the gauge shows around 60 psi, which is my cold oil idle pressure. I then close the manual valve and normally leave it closed for street driving. My concern: when I then open it for prelubing, the gauge pressure only drops to 30-35 psi, which I think is telling me that all the oil in the Accusump is not being delivered to the engine.

Theories? Fixes? Thanks!

waddisme

30 psi is about all I get on my pre-lube. Unless the accusump is not charged fully, it should dump all the oil you have seeing oil pressure is zero in the block. Not sure this answers your question, just how mine does for reference.

marco383

Is your 30 psi reading on the dash gauge or the Accusump gauge? I also doubt that the Accusump is emptying fully, since it's holding that 30-35 psi. I was wondering whether leaving the valve open the next time I drive the car would allow hot oil to free up the piston, or whatever.

waddisme

On the guage. I think on mine the guage is the air pressure to charge the accusump, not oil pressure in the unit. Might have to look at my docs.

marco383

I'm pretty sure that the Accusump gauge reads the pressure on the top of the piston, which should be the air pressure charge when the unit is empty (piston down); when the unit is full (piston up), that pressure should reflect the oil pressure below the piston, no?

My Accusump literature calls for empty air pressure of only around 7 psi.