Summer is Approaching
The H1 Hummer is known to have an over heating issues. Some of the issues are unfounded. We find at Predator Motorsports a lot of the time a little bit of preventative maintenance will prevented this problem. The design of the radiator stack angle makes it conducive to collect debris.
Nearly every vehicle that we do a Cummins or Duramax Conversion has a build up of leaves, pine needles, bugs, and other loose debris deposited on top of the radiator which restricts air flow. When you open the hood, it may look clear, however, you’ll find under the oil/transmission cooler, a build up of loose debris.
I use a coat hanger to probe between the radiator and oil cooler to see if it is restricted by leaves. If it is, you may have to loosen the A/C condenser and oil cooler to reach on top of the radiator to clean it out. While cleaning, be sure not to break or loosen any of the fluid lines.