0949er

Hey a_penguin was telling me how to install my aftermarket oil gauge last night... I just had a real quick question for those of you with a mechanical one... do you have to bleed the actual line to the gauge itself? I was just thinking about that in bed for some reason lol. Anybody want to shed some light on that for me? thanks guys.

My1stGT

nope dont have to bleed it ,, just hook it up and check for any leaks ,,also i wouldnt use the cheap plastic line most come with , spend the extra 10 bux and get the copper tubing

cliffyk

Over the years I have read installation instructions that said to do it, and those that never mentioned it.

That said I have never bled the line for a mechanical o/p gauge--my thought's being that the air will compress to whatever the oil pressure is and pass it on to the gauge--and the bit of dampening the air cushion provides (it would be "sponginess" in a braking system or clutch) is not a bad thing...

0949er

so that air wont "absorb" any pressure? I thought air is compressible to an extent right? wouldn't that make my reading off a bit? Because it isnt pure liquid in the line, so all that force is not going to be transferred completely... right??

My1stGT

if that was the case and i dont think it is then the air would only "absorb" so much until it was totally compressed and your reading is correct( hope that makes sense) i know what im trying to say anyways ...lol. to date my pressure reads fine with out issue .

0949er

no I get what your saying.

Did you use plumbers tape on the streads? Can I trust that hose to set in that gauge securly? I mean, it looks like you tighten it by literly placing that small metal piece over the hose (and tightening)

cliffyk

Air is compressible, however it does not "absorb" any pressure--it will compress right up to the pressure supplied by the oil and then pass that pressure on to the gauge--in the line to the gauge it will perform as an air "spring" and dampen the rapid pressure pulses created by the gear type oil pump.

Hydrostatic load cells and "air over oil" indictors were very common in the pre-electronic era with the air column used to "snub" the gauge and keep it from jumping about. A rope mill I worked for had a test bed for testing rope (up to 1.5M lbs) that was built by the Baldwin Locomotive Works during WWII that used such an indicator.

In the early 80s I converted it to use an electronic strain gauge load cell system from a company named BLH electronics--which we found out during the process was Baldwin-Lima-Hamilton, the result of Baldwin Locomotive's having merged with Lima-Hamilton another locomotive works--they used it in some of their ads...

My1stGT

.yes i used it . just make sure the hose it all the way in the hole on the back of gauge and tighten fitting ,doesnt need to be super tight or you will risk stripping or breaking something.

good luck with install

0949er

so is this the correct way to hook the line up to the gauge and car? (with the addition of plumbers tape), the gauge came with no manual... haha: