Packard Forum Index » V-8 (1955-56)

A link to a professional shop, link to a Plymouth site which has a DIY procedure with some pictures and a writeup on a procedure similar to the Plymouth by one of our own people are located in this thread:https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=88247#forumpost88247

If your capillary tube is not broken doubt the instructions will help. Probably Bourdon tube inside the gauge has been overpressurized and distorted & is what's keeping the needle pegged. If so, would imagine professional will be the best if not only option to have any kind of accuracy at the finish.

Is my 37 115C temp guage a thermocouple or a bourdan tube type? also who can repair mine/ thanks Rich

It's a liquid/gas filled tube with a bourdon-type movement. You might try these folks, John has an excellent reputation for work like this. For the brave-of-heart or exceptionally handy, there was an article in Skinned Knuckles a while back on doing it yourself.

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Having repaired the temp gauge on my 39 120 a year or so ago, and a similar gauge on a 34 Chevy last week, replacing the tube is fairly easy. You will need to get a new mechanical gauge from Napa as a donor for the tubing, plus about 1 to 2" of a very small diameter copper tube to connect the old tube to the new. This is the easy part.

You will also need a very very small drill bit and a pin vise to hold it. When you cut the tubing it will invariably crimp the tube so that no gas can flow thru the junction. After you cut it, you need to take the pin vise and tiny (much smaller than 1/16") and open up the end of the tube. I had to go to a machinist friend of mine in order to get one of these little drills. Don't bother with the ones from Harbor Freight, as they snap easily. Ask me how I know!

You can do this work in an evening, but it the gauge itself has a problem, you still haven't solved the problem. The Packard gauge worked fine after it was repaired, but the Chevy one would only go to 190 when immersed in boiling water since there was something wrong in the mechanism of the gauge. Moral, of the story, it is probably a good idea to send it into someone who can repair both the tube and the gauge. But it was fun fixing the Packard gauge!

The temperature gauge on my 48 is not working also. It is stuck on nearly hot , if the ignition is on or off. So, does this apply to a 48 also . I assume it is electrical, not mechanical on a 48. Thanks

The 48-50 gauge is electric and stays at the hot side when the key is off. They don't use the typical or common resistance type sender though. As soon as the key turns on it should go to the cold side. If it does not, likely causes are a bad or wrong sender, an open wire between gauge and sender or a bad gauge.

To test, have the key off and ground the wire at the sender. Turn the key on and immediately watch to see if the gauge moves to cold. During the tests do not leave the key on with wire grounded any longer than the time it takes to move the needle.

If it moves, you have a bad or wrong sender. If no movement, repeat the process only grounding this time at the gauge terminal on the wire going to the sender. It should be the terminal with just a single wire going into the harness. The power terminal will also be connected on the back of the cluster to the oil and gas gauges so be sure not to ground that side. If gauge moves this time then a bad wire to sender.

If it still doesn't move then assuming the other gauges have power and work, you have a bad gauge.

Ok - thanks - I will try that when it warms up a bit -

Thanks, I spoke to John and my gauge is on the way. and now to find the delco motor and squirel cage defroster for my harrison heater?!