1stC3Vette

I replaced my waterpump and just noticed that the "low coolant" light comes on periodically. I know there is air in the system, but have not been able to get it all out or atleast enough to stop the light from coming on.

I have added coolant to the radiator until it is full. I also added additional coolant to the overflow bottle.

Any hints??

Thanks,
Dino

vader86

Remove rad. cap.
Start engine and let it warm up to the tstat opening temperature.
Hold revs at 2K or so, and you'll see the coolant level drop, thats when you keep adding coolant until its full

Repeat if necessary.

drewber

I usually just take off the radiator cap while the engine is cold. Start the motor and let it idle to normal operating temp. when the thermostat opens the water level should drop. Fill up coolant mix, put on radiator cap, turn off car.

i cannot stress enough to put the radiator cap back on, BEFORE you turn off the car.

cdnguyred88

I also drill a small hole in the T-stat so air dies not get trapped either. This solved my problem of air bubbles on my '88.

rick lambert

And it's best to have the front end elavated a little.

onedef92

On an LT1 or LT4, you should open the bleed valves on the thermostat housing, too.

1stC3Vette

Thanks for all of the replies. There seems just to be a small amount of air, that I haven't been able to get out. I will try the suggestions to run it with the cap off until it gets to operating temperature.

I should have drilled the small hole in the Tstat when I replaced it.

P.S. I did not replace the cap before shutting the engine off the first time and paid the price!! Never again.

Thanks,
Dino

VQT88Vette

Fill the radiator up with the engine running until the t-stat open with the heat control at max, put the rad cap on before the hot fluid spilled out. Fill the reservoir tank to the cold line, check the reservoir tank a few times after driving the car to normal operating temp.

I thought that there is a small hole in the t-stat already.

Vetterin

On almost all t-stats there is a hole AND that hole should be pointing to the top of the t-housing when installed.

LD85

rickneworleansla

I changed my coolant a few week ago. My 95 had a release valve by the thermostat. Not sure about older c4's. I also overtightened the valve and broke off the top peice. oops. Oh yeah, one more thing, dextrol sucks! Use the older green stuff and just change it out every summer or two. Your corvette will appreciate it. I payed to have it flushed twice and they still couldnt get all the funk out. Then a shop couldnt figure out why it was overheating and wanted to start replacing the whole damn system for around a thousand dollars plus. New radiator, water pump, etc.,etc. Yeh right! Thats when I did it myself. It took me hours to clear all of that orange funk out the system. Now she runs cooler than ever.