2nd Gen Non-Engine/Transmission High Head Pressure

[steamboatinn]

2002 3500 Head pressure reads > 300. Ambient air temp was 90F. Any ideas? Thanks.

 

[Bob4x4]

# 1 cause would be lack of airflow over condensor,check your fan clutch

 

[Tuesdak]

Fan clutches wear out loosing 200 RPM per year and should be replaced at 5 years old. Computer controlled fan clutches can compensate for this. Spring thermal ones can't. Have you hosed out the condenser and don't overlook a bunch of bent fins stopping airflow. Spring thermal fan clutches don't work until the radiator also warms up and starts adding heat as the set points are 180+ for fan clutches to kick on.

Normal operating temperature IMO for hot weather is 160 degrees on the condenser after engine warm up. This is 300 psig. Verify condenser temp with an IR temp gun and see if it's close to the noted pressure. (I don't worry at 350 psig as our weather hits 121 degrees.)