nvrenuf

I had an A/C repair yesterday and the shop says they think the fan clutch is bad. Their opinion is based on the A/C system having high pressure like the condenser isn't being cooled adequately. They replaced the discharge hose and the A/C is COLD now but insist there's a cooling issue. What / how can I check this myself?

No codes, engine temp always normal, NEVER runs hotter than straight up on the gauge (200°) and if I try to spin the fan by hand it only moves 1-2 blades.

2006 4wd, 5.9, G56 & 150k miles. Totally stock except for a Southbend clutch.

Busboy

High head pressure is caused by either a partial blockage on the high side like a kinked line or a flattened part of the condenser or by not enough cooling through the condenser. This could be caused by a bad clutch fan a dirty radiator or condenser not allowing enough air through or flattened fins on the condenser. Any winter or summer front should not be up against the condenser. It used to be you could check a clutch fan by having the engine hot then shutting it off, hold a fan blade with a piece of cardboard and start the engine, if you could hold the fan it was junk. Newer clutch fans are electrically controlled to engage when the AC is selected on or there is a need for extra cooling. I don't know what kind you have but I hope this helps.

nola

This is accurate to a degree. However, on my 05 when I pinned the fan clutch the AC would run fine and start up fine on crank. No pinning and pressure would build and freon would blow out. Broke down and bought a new clutch assembly and no problems. I'm told they do build pressure on crank and can release a very small amount of freon. Now I always crank without the compressor engaged.

carl48

i had the same problem after fix, the 06 has a expansion tube, not a valve, it is located underneath the passenger side battery, when we cut it open the screens were partially blocked with trash, there is no way i can see to clean it, the expansion tube looks exactly like part of the line and you can not spot it, the only thing you can do is repace the line

nola

Make sure to get the upgraded larger orifice for 08 models. Easy swap. Just have to remove battery/tray to get the whole line out. I've heard of people cutting the line and retrofitting a larger replaceable orifice tube.