few cooling systems issues

andrewkirby88 · Nov 23, 2016

I had to replace the water pump on my 1950 TO20. I ordered all the parts from this site. It didn't have a thermostat or temperature gauge so figured if I was tearing it apart Id change the coolant,pump, and add the thermostat and gauge. The pump went it fine. I installed the thermostat according to service manual. The problems I'm having is the probe and nut that go into the neck for the gauge seeps it feels tight but it keeps dripping especially prior to the thermostat opening seems to stop or slow when thermostat opens. Problem 2 is I filled system with water to test everything prior to switching to antifreeze and seemed to work well however once it reached temperature and thermostat was above 180/200 it seamed that the temp would rise quickly on the gauge and then it would come out overflow the temperature would then drop and be back to normal. Was this the systems way of eliminating excess water? Any help or suggestions are appreciated especially on the gauge probe.

Bruce(OR) · Nov 23, 2016

Your stat does not have a piddle valve to keep it from peaking the temp gauge. You need to drill a 1/16" hole in
the side of it to allow trapped air to pass through and some warm water which gets the stat to open easier
rather than slamming open and shut.
That's 2.
As for 1, is your leak at the threads? Try using teflon tape. I prefer the yellow tape for natural/LP gas lines
because it is thicker.

Ark68SS · Nov 23, 2016

(quoted from post at 19:44:51 11/23/16) Any help or suggestions are appreciated especially on the gauge probe.

On my TO20 I found that the end of the probe was hitting the housing. I used a burr on a die grinder and carefully ground the housing for clearance. Then I was able to tighten the nut just a little more and it sealed.
Drain the coolant and remove the hose so you can see inside the housing. Remove the nut from the gauge probe and push the probe into the housing while looking through the hose inlet to see if the probe bumps into the side of the housing. If it's hitting, then you'll need to grind.
BillL

Jerry/MT · Nov 25, 2016

refill the radiator to about 1/4 inch above the top of the core. The fluid need expansion space when it heats up. If you fill the radiator to the bottom of the filler neck, the coolant will run out the overflow and level itself.

few cooling systems issues

andrewkirby88

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Bruce(OR)

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Ark68SS

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Jerry/MT

Well-known Member

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