The Stovebolt Site Forums The Shop Area The Electrical Bay Temp Gauge Problems - Needle pegged

Hello All,

I have a 1952 Chevy 3/4 ton pickup. During revival, I wanted to go with the GMC interior color, beige/tan that I remember from my days riding around in 1950's Chevy's. I do none of my own wrench work and the mechanics I hired installed a new GMC gauge cluster from Chev's of the 40's. Everything went fine for 10 years, then I overheated the truck (short of coolant -- my bad). The engine temp gauged pegged and when the truck cooled down, the needle stayed pegged.

Now what? Any sly tricks to restore function or do I have to replace the gauge set?

Best hopes,

HH

It sounds like your gauge has been broken. Please let me try to explain as you only have one option if that happened:

When the truck was designed and built, the temperature gauge was controlled by a heat sensor and a capillary tube. The tube connects in a sealed system to a bourdon curl inside the gauge. This curls or uncurls based on the pressure of the expanding liquid in the capillary tube (which is what causes the needle to move) and if exposed to very high temperatures can become stuck at the upper most position of the needle. It isn't common, but I've seen it happen and in basic terms the bourdon tube/curl becomes unusable after that. To remedy, you need to buy a new heat sensor and gauge...but not the entire gauge cluster. It will come with a new capillary tube which can be installed very carefully (so as not to crimp the tube) and that should restore your temperature gauge.

If you don't do any of your own repair, hopefully you know a friend who might be able to remove and replace the gauge. Good luck!