Why does my 2000 year Chevy C3500 truck recovery tank overflow only when A/C on?

[Tim Frank]

Re: Why does my 2000 year Chevy C3500 truck recovery tank overflow only when A/C on?

+1 ^
A competent garage should be able to test some of the coolant from the overflow tank and check for exhaust gases.

Had that exact problem with a Subaru....but then, Subarus are notorious for head gasket failures...

 

[GA_Boater]

Re: Why does my 2000 year Chevy C3500 truck recovery tank overflow only when A/C on?

Sometimes you can take the cap off, look for bubbles and sniff for exhaust odor.

 

[Big Bubba]

Re: Why does my 2000 year Chevy C3500 truck recovery tank overflow only when A/C on?

Took my truck over to my fathers house to deliver some push mowers I worked on for him to sale at the local flea market over the Fourth of July weekend and my truck never overheated nor the expansion tank overflowed on me and he lives about 14.4 miles from my house. Keeping my fingers it is good to go now as a maintenance I am going to be doing a complete flush since the coolant inside the radiator looks dirty with some particles floating within the coolant.