Fits: 2001 Thru 2016 Chevy Silverado/GMC Sierra 2500HD/3500HD LB7/LLY/LBZ/LMM/LML Duramax Diesel

For years high performance Duramax diesel engines have suffered from water pump failures.  As the rpm limits have been pushed higher and higher, little attention has been given to the fact that the water pump is capable of pumping far more water than can flow through the block and cylinder heads. As the rpm increases, so does the pressure between the pump and the block. Once this pressure meets a critical point, something has to give, it could be any of the following, the water pump drive gear spins on the shaft, impellers break or spin on the shaft, bearing or seal failure. Similar failures have been known to occur during abrupt rpm changes, such as converter lock up or gear changes. 

The water bypass kit is essentially a blow off valve or waste gate for the Duramax cooling system. Once a preset pressure is reached , the bypass valve opens and excess flow/pressure is bypassed back to the radiator. This system allows the pump to continue operating at maximum efficiency no matter how high the rpm goes. Any pressure wave spikes in the system during abrupt rpm changes will also cause the bypass to open, thereby dissipating that harmful energy.

DmaxStore Notes: 

• Bypass valve mounting location is up to end user

• Hoses and additional fittings may be required

• If optional upper radiator hose return adapter is not purchased, you will need to add/fabricate your own coolant return port