79 GMC C3500 overheating

1979 GMC C3500
V8 • 2WD • AUTOMATIC
Avatar
SMURPHY85
  • MEMBER
  • 2 POSTS
I have a 79 GMC C3500 with a 454. The truck is overheating and I cant figure out why. I just replaced the radiator with a new 4 row, burped the system and topped off the fluid. The thermostat is 4 weeks old and I tested it. It still wors fine. The water pump is still good, not cracked or leaking. The fan is working strong. Any ideas?
Dec 12, 2010 at 3:21 AM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
Advertisement
Avatar
MHPAUTOS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 31,937 POSTS
Are you using any coolant, have you tested the radiator cap?

mark (mhpautos)
Dec 12, 2010 at 4:00 AM
Advertisement
Avatar
SMURPHY85
  • MEMBER
  • 2 POSTS
Yes Im using coolant and the radiator cap is fine. Its not leeking radiator fluid anywhere
Dec 12, 2010 at 4:27 AM
Avatar
MHPAUTOS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 31,937 POSTS
You will have to get a head check done, this will check for a head problem.

mark (mhpautos)
Dec 12, 2010 at 6:24 AM