I have a mechanical oil pressure guage, with a copper pipe I'm running to a T peice where the original pressure sender is.

My question is, do you need to somehow bleed the copper pipe?

If I just put it all together where does the air in the pipe go? Air compresses so surely gives a poor reading.

Cheers,
Stu

 

The air will compress to the same pressure as the engine oil so the gauge will read correctly. Make sure there are no kinks in the pipe or it won't read. Also allow for the movement of the engine relative to the bulkhead that the capilliary goes through, otherwise the pipe will crack and leak engine oil out, possibly up behind the dash. You'll soon smell/feel it if it does leak into the cabin.

 

Also make sure that it stays away from any wiring as if something short-circuits then it could use the copper tube as an earth and cause a fire. Have seen it happen and seen the results. Best thing is a thin convoluted plastic tubing round the outside of the copper pipe,both inside and outside the engine bay.

 

Brilliant, thanks. I have 6ft of tube with the guage, so plan on coiling it between engine and bulkhead to allow for movement.

Will wrap the tube to stop it conducting. Good point!