thermostat bleed screw

tacomagabe · Post by **tacomagabe** » Thu Oct 22, 2009 9:43 pm

Changed the coolant today. Drained the radiator no problem then moved onto the cylinder head coolant bolt. Took that off and wow. I had to scrape and prod for about 5 mins to get through and let the coolant out.

Anyway everything went good except my thermostat bleed off screw on the top was so week and rusted there was no way I could turn it without stripping it out. I was wondering
A. Anyone know where I can buy one separate from a thermostat?

B. If I can't bleed the Thermostat right away will this mess up it's operation? I could see some air trapped in there throwing off it's temp readings maybe? Maybe not opening when it should? I'm getting some warm air from the heater though...

Any thoughts?

GripGreg · Post by **GripGreg** » Thu Oct 22, 2009 11:58 pm

Yes, there will be substantial harm if the tempature needle goes past 3/4.
This is one of the very few parts you should buy at the dealer! Ask me how I know these things. Whew!
The screw/plug on top of the water pump shouldn't cost more than 5 bucks' and that's givin' it some latitude. Make sure it's the one with the head on it.
After you've bled the system everywhere else; this is the LAST thing to be done. BUT, MAKE SURE YOU BLEED IT! Don't tighten too much.
The reason the screw is corroded is 'cause it was done correctly. It may not need to be checked for 5 years, depending on the quality of anti-freeze, and hoses used. I hope this helps,,,,Greg[/i]

Lenny D. · Post by **Lenny D.** » Fri Oct 23, 2009 2:14 am

The later thermostats have a hole in them to pass some water even when it is closed. Theoretically, it is a self-bleeding device, pushing water (and trapped air) through the system. The air eventually winds up in the reservoir. That is not to say you don't need to bleed the system, but the owner's manual indicates running up the idle to 4k RPM with the heater on max. until you have heat. If you have heat the water is circulating.

The newer style bleed screw is the only type now available from the dealer for about three bucks. If you cannot remove the old one, or it breaks, you can replace just that portion of the t-stat assembly, or try and remove the old screw on the bench, which means opening the cooling system again.

wkohler · Post by **wkohler** » Fri Oct 23, 2009 4:42 am

I can send you a bleeder screw. They're only a couple bucks from the dealer, but I've got a few I've collected at the yards.

PM me your address.

YouTube · Post by **Peter Florance** » Fri Oct 23, 2009 6:41 am

I drilled a hole in a piece of steel flat stock and mig welded it to the rest of the bolt. Then (after lots of heat and PB Blast) I put firm but not excessive force on it while tapping on the top of it with ball peen hammer. It came loose. See pic from cooling systems FAQ below

Larger version of the picture:
http://www.firstfives.org/faq/cool/weld ... _screw.jpg

Odometergears · Post by **Odometergears** » Fri Oct 23, 2009 1:58 pm

put a torch to it after you soak it with rust spray. Once hot, tap on the top with a hammer. Then and only then try to turn it. Go both ways at first until it comes loose.

Jeff C, NN, VA

tacomagabe · Post by **tacomagabe** » Fri Oct 23, 2009 2:25 pm

Thanks everyone, great input. I'm sure I can use one of these methods to get the screw out.