Found some really old thermostats and wondering if I should use them or not. I think I got them in 82. They’ve got slight tarnishing — any thoughts or help is welcome!
More than likely. Just check by immersing in water, then heating with a thermometer in the water. Observe the action as the water temp reaches the indicated temp on the thermostat.
It would be funny... If it weren't true.... Forty years ago our parts came from USA... Not so much these days..
My mechanic neighbor just put a new crate motor in a 95 Chevy van and has gone through 4 brand new thermostats because they were all bad right out of the box and causing initial overheating from a cold start.
I check them all that way. Last time I bought a t-stat I went through 3 before getting one that was right.
That's how we would trouble shoot a cooling problem 40 years ago in the garage I worked at, rather than just putting a new one in.
Wanted to thank everyone for their help! I put the NOS Robertshaw 370-180 in boiling water and it opened right up! Installed it this evening.
