1986-1989 Honda TRX250 FourTrax 250R Service Manual, Page 109Get this manual
COOLING SYSTEM
COOLI NG SYSTEM INSPECTION
(1) RADIATOR CAP
The engine must be cool before servicing the cooling system, or severe scalding may result
Remove the front fender (page 14-2)Pressure test the radiator capReplace the radiator cap if it does not hold pressure, or if re lief pressure is too high or too lowIt must hold specified pressure for at least six secondsNOTE Before installing the cap on the tester, apply water sealing surfaces
COOLING SYSTEM TESTER (COMMERCIALLY AVAILABLE)
RADIATOR CAP RELIEF PRESSURE: 108-137 kPa (1.1-1.4 kgcm16-20 psi) Pressurize the radiator, engine and hoses, and check or leaksCAUTION