Letters and Emails

Published in the October 2010 Issue October 2010 Column

Dear DT,
I think it would be really cool if you did a full issue on Reality Trucks. I love to see other guys using their own trucks everyday.

Nick Valenti

Great idea. We're asking readers for more submissions in this issue's The Wastegate, and we'll keep your idea in mind for a future issue. -Ed.


Dear DT,
I purchased a 2007 Chev 3500 Duramax. When I check my fluid levels in the morning the upper radiator hose is collapsed. I have had the cooling system cleaned and a new small return hose replaced on the coolant tank. This effort has not had any significant effect on the hose collapsing when the engine is cold in the morning before you warm up the truck. Do you know what is causing this problem and is there a fix?

Jack Bayless

It's a common problem. The cap on the coolant reservoir has a check valve in it that gets either gummed up or jammed against the inner lip of the cap. Remove the cap and inspect it to see if the valve is jammed or needs to be re-centered. If it's fine, take the cap and soak it in warm soapy water and gently clean it out. -Ed.


The replacement of the cap was my first move and it did not make any difference.

I reverse-cleaned out the small hose attached to the reserve tank and the next morning the upper radiator hose was normal. I believed that the tank was full of some trash so I took it to a Chevrolet service center to have the cooling system cleaned with the tank. The reserve tank was taken off when the cooling system was cleaned but they could not clean out one of the sections of the tank. It seems like the tank may be the problem. They say that this problem will not cause any damage to the engine.

I checked a 2010 and 2011 Chevy 3500 Duramax and they have changed the design of the tank. Maybe the Chevy people know more than they are letting us know.

If you have any other suggestion please let me know.

The next place we would suggest looking at would be the water pump. Once they start to go bad, we've seen them cause what you're experiencing in a couple cases. -Ed.


Thanks for your prompt reply to my concern. It's possible that it could be the water pump but I have not had a problem for about a week. I added some coolant to the reserve tank a week ago and since that time the upper hose has not collapsed.

The reserve tank has 3 sections and one of them is still not completely clean. They could not clean it when they reversed-flushed the cooling system because of the way it was designed. They took the whole tank out but the tech showed me how that section could not be cleaned.

I am not sure why everything seems to be working right but it is. Yesterday we drove the truck up and down the mountains to Breckenridge, CO, from Fairplay, CO, and back, which is about a 100 miles. This morning I checked the hose and it was fine.

We are camping on a mountain at about 10,000-ft. Some say that could be the problem but they are just guessing.

Like I said, the holding tank has been redesigned on the new Chevy trucks and I think Chevy had a problem they fixed with the new design. Do you have some source that might know? If so I would like to know.

We don't have any ins with the GM engineering department, but we'll put something in here if we can dig up a response. -Ed.

  • Like what you read?

    Want to know when we have important news, updates or interviews?

  • Join our newsletter today!

    Sign Up
You Might Also Be Interested In...

Send to your friends!