Reader Question My coolant is dirty. Is the transmission fluid mixing with the coolant? If so, is this a radiator problem?
Hey LaShanda, how are you?
Your coolant is probably dirty due to rust and normal carbon and calcium deposits and not from your transmission fluid. Transmission fluid COULD get inside the radiator if there was an internal leak in the radiator due to an accident or something but doubtful. The transmission fluid would float on top of the antifreeze in small droplets.
You should have your coolant/antifreeze drained and refilled every 45,000 miles or so as maintenance. I also like to replace the radiator cap at the same time.
Reader Follow up
Thanks so much for your reply. That helps a lot. I did forget to include the fact that I just had the part that holds the coolant replaced with a new one (which is clear) one week ago and it’s already brown.
The mechanic says it is from the transmission mixing with the coolant (without looking at it) and that means the radiator has a crack in it and needs to be replaced. Help!! Your thoughts? How can I pay you for the valuable information.
Hello Again LaShanda
I think I would find another mechanic for a second opinion. Coolant will turn rusty brown/red IF there is a leak in the cooling system somewhere allowing outside air to enter the coolant system thus oxidize like a piece of steel left out in the rain…it starts to rust.
You can check the transmission fluid level to see if its low…but I don’t think you have transmission fluid leaking inside the radiator. Although in this business I never say never. Hahah, but doubtful.
If the coolant is low inside the radiator I would suggest you get a cooling system pressure test to inspect the system for leaks, if you don’t have any leaks…get the old coolant flushed out and filled with new. I would assume you just need to have the radiator flushed out and new coolant added…which is a job any fast lube place can do.
You don’t owe me anything.