Mod Mafia HD Cooling System

(2 customer reviews)


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We have been running H1’s in Texas for over a decade and we have the recipe to keep your truck cool and dialed in no matter what you use it for.

We believe the only way to address the cooling system is to increase air flow and have better engine coolant flow.

System includes:

– Ceramic Coated Balanced Flow Water Pump (Mod Mafia Original)  A drastic improvement in coolant flow and helps guard against #8 cylinder issues.  Early water pump designs that came on the Hummer H1 and HMMWV have several built in flaws.  This is the solution.

– Mod Mafia HD Cooling Fan  Hand-cut in house to fit the unique Hummer H1 and HMMWV fan shrouds.  Designed with clearances for extreme offroad use (flex).

– Mod Mafia HD Fan Clutch  Has a higher percent lock up and also starts to lock up sooner to help with heavy loading and to keep the cooling system as cool as possible.

– Bypass Restriction Fitting (BRF)  To help engine coolant temp the factory replaced the single thermostat housing with a dual thermostat housing for better flow to the radiator.  The engine coolant will take the path of least resistance.  Therefore, we are increasing the resistance for the fluid to short cycle and bypass the radiator.  This increases the amount of coolant actually traveling through the radiator and therefore reduces engine coolant temps.


2 reviews for Mod Mafia HD Cooling System

  1. Fletcher

    No heat issue with this outstanding upgrade.
    We’ve had our 2000 H1 in the family since it was new. For years one of the only issue we had was the engine running hot. My dad actually overheated the engine in the Atacama Desert and ended up cracking the block (#8 cylinder). That engine was replaced under warranty but later continued to stuffer from running hot when it was hot or the engine was being pushed going up grades. So far the upgrades from this system have eliminated that issue. I’ve had it in the Mojave Desert and Death Valley without any issues.

  2. Tyler M.

    Was my fix! It does fit very tight to engine almost in contact with harmonic balancer.
    Is a very nice fan well built.

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