Take the pressure relief valve off the pump noting the order of the parts. The relief spring determines the bypass pressure
for the pump. If you want to increase pressure, the easiest way is to add washers behind the end of the spring increasing
spring tension. Sizing and thickness are important. If you use a Saginaw style pump, there are kits available to alter the
pressure. Other brands are similar in method. Read this article completely for a full understanding:
