'34 dual gauge problem
 

I had my dual gauge (temperature/fuel) rebuilt and installed in my model 40 last week. When I picked it up from the shop, the temperature gauge wasn't showing any red color but I assumed it was because the engine was cold. On the drive back (about 20 miles)I could detect just a hint of red at the very bottom, not even up to the "cold" mark.

I took it back in yesterday and we took the sensor loose from the radiator hose and plunged it into a cup of very hot water. The red liquid in the glass tube came up about half way between the cold and the hot readings on the gauge.

We reassembled it. I took it out for a drive to warm it up and nothing! Not even a hint of red.

Any ideas as to what could be going on?

Re: '34 dual gauge problem
 

What temperature is the engine getting up to? Use an IR gun to check it at the water outlet from the head back to the radiator (each side).

Re: '34 dual gauge problem
 

Who rebuilt it? I had mine done last yr by a company in OH and it registers quickly and correctly.

Re: '34 dual gauge problem
 

Hey J
He used a IR gun and it measured from 130 to 160ish. We microwaved 2cups of water. I don’t know what the temperature was.

Re: '34 dual gauge problem
 

It was rebuilt by a company in Il. I spoke with them. They are as baffled as I am. The sad part is the temp gauge worked fine before rebuilding. I had to have it rebuilt because the housing was rusted out.

Re: '34 dual gauge problem
 

Why don't you boil some water in a pot on the stove. When it is bubbling good, take the pot to the car and put the sensor in it. The water should still be above 200 degrees and the sensor should indicate hot.

Re: '34 dual gauge problem
 

Maybe in the ground circuit, sometimes a sealant is used on the threads and you don't have a good ground, before taking the sender back out try using a wire to the sender base and a good ground.

Re: '34 dual gauge problem
 

This is a mechanical gauge - basically a very LONG thermometer . . . with a capillary tube that connects to the temperature bulb. It strictly measures heat and the red liquid expands into the sight glass.

Re: '34 dual gauge problem
 

Check the radiator coolant level you may have lowered it to remove the temperature bulb and install after rebuild, may have forgotten to refill.

Re: '34 dual gauge problem
 

Terry, We topped off the the radiator with coolant after we “tested” the sensor in by plunging it into hot water. I plan drain the radiator down again and try the hot water again. This just doesn’t make sense that the gauge will work outside the radiator hose but register nothing when hooked back up!

Re: '34 dual gauge problem
 

Could it be a kink in the tube that connects the gauge to the temperature probe -Karl

Re: '34 dual gauge problem
 

I w ent to Harbor Freight and bought an IR gun. I drained the radiator down to the level of the sensor. I stuck a gallon milk jug over the hole as soon as I removed the sensor. I was able to save over 90% of the coolant.
I took boiling water from the stove and put the sensor into the water. I measured the water temperature at 145 degrees. My wife sat in the drivers seat and photographed the gauge. It barely crept into view.
I looks like this gauge is going back the restorers. Thanks for the help.
Richard