Power steering fluid should be kept at 180 degrees or lower. We chose the largest cooler that would fit the available space for both the steering and transmission: 29,200 BTU B&M Super Coolers. Cross Enterprises mounted them using flat stock—stouter than the nylon-tie method. Mounting the coolers ports-up helps in bleeding air out. The steering fluid level is higher than the cooler, and the cooler return line shouldn’t drain into the reservoir with the engine shut off.