I have a 2004 lb7 over heats only with a heavy load 10,000 or larger, climbing fairly step grade. I put in a new water pump, fan clutch, thermostats, hoses, radiator cap on my mechanic's recommendation. I had a flow test done it was ok. The mechanic says now it might be a head gasket. I am not losing antifreeze and am not getting build up in the reservoir, no sign of antifreeze in the oil. does anybody have any ideas
LB7: over heat problem
- Thread starter Jgord
- Start date
Dumb question but did you remove the radiator and clean out intercooler/evaporator area? A friend of mine was having over heating issues and I told him to take the core support off and clean all the junk out. It's amazing what you'll see in there.
Do you have all your original air damns? Where is your air intake routed if not factory? Take the radiator out and clean it with CLR or something like that, I've seen some nasty junk come out of them.
Yellowchevy
Here's an idea of what it could look like if its never been cleaned before, this is pretty excessive but you get the idea.
Attachments
What rpm do you turn while climbing these grades and do you hear your clutch fan engage? Also what temperatures are you seeing?
I have original air intake, the stack of coolers has been cleaned with water only. I am seeing temps of 250+, rpms of 2700,fan clutch engages good
Thanks for the clarification, I realized my error once. Just had one of those dumb moments!!
Yellowchevy
Thanks for the clarification, I realized my error once. Just had one of those dumb moments!!
Yellowchevy
Ive lost track of how many times I've heard people say that lol.
Pull the radiator out and clean it thoroughly before you go any furthur. If the fan clutch is engaging, and the temps are still climbing, then it sounds like the air isn't getting through the cooling stack. If not that, then you have a problem with combustion gases getting into the cooling system, but this would show it pushing coolant out.
Well I Removed and pressure cleaned the stack, it still overheats with a 11,000 lb load going up a 1.5 mile 6% Grade although I noticed that it stays at 200-210 until it shifts out of passing gear near the top,
then it almost immediately jumps up to 240-250
then it almost immediately jumps up to 240-250
Its possible the impeller is slipping. its a known issue on 01-05 that's why we tig weld them on and the gear.
:hello: Climbing harper hill?? lol
I agree with the others, water pump impeller maybe slipping