DieselSite Transmission Cooler Bypass Delete Kit, Ford (1999-03) F-Series & Excursion 4R100

From 1999-2003 the Ford Automatic Transmission (4R100) had an external cooler bypass tube that redirected transmission fluid from the pump output back to the return line of the transmission. The bypassing of the cooler was supposed to happen until the fluid reached operating temps. Unfortunately, these bypass tubes commonly fail preventing transmission fluid flow to the cooler. Another design flaw is even when operating perfectly, the bypass never fully closes, meaning not all fluid is ever sent to the cooler, ever.

The result: transmission overheat.

Many delete kits are available on the market that eliminates the bypass tube and the common failure. However, these kits do not address the restriction in the banjo bolt. If you look at the cut away photo of the banjo bolt, you can see the spring and check ball which restricts about 75% of the fluid flow to the cooler. The spring and check ball was designed to allow the proper function of the cooler bypass tube. Once the bypass tube is deleted, this check ball and spring are no longer needed.

Will not work on E-Series 4R100 Cooler Bypass.