When installing a mechanical oil pressure gauge, is the air supposed to be bled out of the tubing, so that there's solid oil from the engine to the guage (like brakes lines are supposed to be)? The instructions that came with my new gauge don't mention anything about that, and it seems wrong.

Thanks.

Reid

I've installed a few of these and never had to bleed any air. It takes a few seconds for the gauge to register, but after it does it'll read fine. Word of caution, do not use the nylon tubing that may have came with the kit. It's a MUCH better idea to use 1/8" copper tubing. I like VDO's tubing becuase it does away with compression fittings and includes a flared which is really nice.

I believe engine oil can 'compress' the air, so to speak, and also it is not a hydraulic setup, so I don't see any reason to need to bleed it (I haven't)...

I agree to get rid of the nylon and replace with either copper or braided tubing...

I didn't bleed mine and it has worked great for a long time now.

Well, that's it then, thanks! I think I'll keep bleeding my brakes, though. smile.gif

Reid

It wouldn't hold a "bleed" anyway - the oiling system isn't a "closed" system like the brakes, it's vented to atmosphere. When you shut the engine down it'll drain back up to the highest spot. Use copper! Nylon gets brittle. Having 200+ degree oil spraying inside the car is not fun!
(Bought a winter beater that someone installed a mech. OP guage in. They used the plastic tubing. After replacing some dashlight bulbs (and not knowing I cracked the line doing so) and going for a ride I had hot oil spritzing all over the place!

Originally posted by John D:
It wouldn't hold a "bleed" anyway - the oiling system isn't a "closed" system like the brakes, it's vented to atmosphere. Of course! graemlins/clonk.gif Thanks.

Reid