Oil Gauge Repair

[Patrick H.]

Hello All,

While putting the dash back togethr on Dad's 72, I (wisely) decided to test the oil gauge before I put the center gauge section back in place. As my memory served, it didn't work when I took the car apart 2 years ago.

Well, it still doesn't work now. New oil gauges do not seem to be plentiful, nor are they cheap. Does anyone know if this gauge could be repaired, and if so, by whom? Or is there a reasonable source of used gauges?

Thanks for your assistance,

Patrick Hulst

BTW, using a different gauge worked well (40# pressure using a primer to spin the pump), and there is oil all the way up to the gauge in the oil pressure tube.

PH

[Joe L.]

Re: Oil Gauge Repair

Patrick----

This is your lucky day! The 68-71 and 72-74 oil gauges used to be one of the most difficult of all of the C3 gauges to find (I've stashed away 2 NOS 68-71 gauge sets, so I've effectively taken those two out of circulation). However, wonder-of-wonders, EC Products of Atascadero, CA has recently come on the market with exact reproductions of all of the 68-74 gauges. The sell for about $80 each.

You may be able to have your gauge repaired, though. I'd try Corvette Clocks by Roger. I believe that he rebuilds these gauges if they are rebuildable. The oil gauge often isn't.

[Wayne W.]

Re: Oil Gauge Repair

Generally you can get them going yourself if you want to. Remove the guage from the housing exposing the inner works. Just oil the mechanism with something like WD 40. Then carefully massage the expansion chamber that you see on the back of the guage. It is connected to a fan gear you can gently tweak that a little. It will usually break loose. Once loose move it back and forth several times. It will be good as new. They stick because of moisture. There is little else to go wrong with them.

[Roger Coen 30751]

Do they have 80# for 67's?

If so Joe got a phone or web site? THX

Roger

[Joe L.]

Re: Do they have 80# for 67's?

Roger----

No, at the present time all they are reproducing is the 68-74 gauges. Their phone number is 800-488-5209.

[Patrick H.]

Re: Oil Gauge Repair

Wayne,

As I understand it, I take WD-40 and squirt it in where the oil line connects. I then wiggle that big brass(?) curved piece wrapping around the back of the gauge circumferentially, until the gears seem to loosen up, and the whole mechanism works better.

Is this it? I hope so, 'cuz this is what I did. The whole mechanism seems to work better, but I'm confused as to how the oil going into that round base will rotate that brass (?) piece and turn your gauge.

Patrick

[Wayne W.]

Re: Oil Gauge Repair

Patrick, Oil the gear and the mechanism not inside the oil line fitting.

[Patrick H.]

Re: Oil Gauge Repair

Wayne,

I oiled 'em all, and it seems to work easier by hand now. Just thought I'd check before I go and try it again on the car,

Thanks,

Patrick

[Bob Lanham #32271]

Pressure readings

The 69 427/390 I bought has high readings on oil pressure. Its around 80lbs when driving. The guy I bought it from "fixed it". Is there a way to change the pressure readings to reflect what the books say? I know I should probably check the pressure with an external gauge first ( don't know where to get one). Also the car has a non-stock cam. I'm not an expert and I'm not real familiar with stock 427/390s, but the cam seems to be racier than stock. Could the cam be causing the high pressure? Engine was supposedly rebuilt about 15,000 miles ago. I can't tell if any other performance mods were made. I was told the comp ration was dropped 1/4.

[Michael W.]

Re: Pressure readings

Bob,

I think you first should establish what pressure your engine is actually running at, by way of either connecting an external gauge, or substituting a known good gauge in the car.

The cam you are running, or compression ratio of the engine will not affect your oil pressure in any way. Oil pressure is a function of output of the oil pump (pressure/flow) versus restrictions downstream, such as diameter of passages, bearing clearances, etc. plus viscosity of the fluid. It is very possible that whoever built your engine put in a high capacity pump and took measures to ensure that the clearances were as tight as possible, resulting in 80psi oil pressure.

Please don't go trying to change gauge readings until you know what the real pressure is!

Mike


NCRS Quebec chapter