Why It’s Important to Pressure Test Your Cooling System on Your John Deere Engine

What Is a Pressure Test?

A pressure test involves using a coolant system pressure tester to simulate the normal pressure conditions of your machine's cooling system while the engine is off. By pressurizing the system and monitoring it, you can identify leaks that might not show up under regular conditions.

Real Example: John Deere R430 Sprayer

While performing a routine inspection on a John Deere R430 sprayer, there were no complaints from the customer about leaks or cooling system issues. But we decided to do a pressure test as part of our standard procedure.

Using a coolant pressure tester, we hooked up to the reservoir cap and pressurized the system to its rated 15 PSI. With the valve shut off, we could monitor the pressure for drops and start looking for visible leaks.

Sure enough, we found one.

What We Found

A leak was detected on the lower radiator hose. At that point, we tightened the hose clamp and blew the area off to get a clean look. With the system still pressurized, there was no further sign of leaking.

Had we skipped this test, the customer may have gone on to experience overheating in the field or unexplained coolant loss—both of which could lead to costly downtime.

Why You Should Pressure Test

Even if no symptoms are present, a pressure test can reveal hidden issues that aren’t yet visible. It’s a fast way to potentially save time, money, and headaches down the road. Especially during inspections, it’s a smart preventative step that adds value to the service.