07 Pete 379

Gotta watch doing that. These new compressors now days do not take well to being overcharged. Makes them cranky and they start making all kinds of strange noises till they lock up.

 

ANY system is cranky when overcharged. Blow the whole charge and put in the exact amount specified on the label. If there is no label, charge it until the sight glass in the receiver tank doesn't show any bubbles. If there is no sight glass, charge it until the outlet pipe (bigger) is cold and approximately the same temp as the inlet.

As for the OP... is the compressor running? Cycling fast?

Sounds like someone might have ripped you off. A system is either CCOT (Cycling Clutch Orifice Tube) or TXV (Thermal Expansion Valve) they do not have both in the same system. Most trucks are TXV.

 

I had to change the condessor on mine. the one I replaced it with was larger so I filled it buy the sight glass. The compressor went and the dealer said it was over charged. It only cost 800 bucks for that learning exp.

 

Now I'm curious... why did you have to change the condenser? Wrecked, or did you have a compressor failure? Did you add oil after changing the condenser?

A compressor will fail because of a few things...

1) Lack of oil from chronic under-charge or not enough oil in the system. (Changed a major component and didn't add back the amount of oil removed)

2) Metal contamination from a previous catastrophic compressor failure. If the system has not been flushed, install a liquid line filter just after the condenser.

3) Serious overcharging causing liquid refrigerant to hit the head. (Hydraulic lock = Kaboom!)

It's possible that the compressor might fail from an overcharge that results in extremely high operating pressures, but at that point, the system wouldn't cool anyway.

If your system was working and cooling good before the compressor failed, it wasn't overcharged enough to kill the compressor. The dealer is blowing smoke up your ###.

 

The condenser got a pin hole in it no damage that I could see. I did add a can of oil charge. If my memory is correct I think it was 2 oz of oil in it. After that the low side schrader valve leaked a little and I would add when the evap. would freeze up. Fill buy the sight glass.

 

consider yourself caught....haha

 

Sounds like your system was working and cooling properly after you charged it. Two ounces of oil may have been a little slim for a condenser replacement... it's been a while since I worked in the shops, so I forget what the standard amount was. If you can drain the oil out of a compressor/condenser/receiver tank when you replace it... measure it and put back the same amount.

I'd say in your case, the dealer was smoking crack. It doesn't sound like you overcharged it.

 

Here is a tip for when you guys get you A/C working again. Go to a Lowes or Home Depot store and get a roll of alum bubble wrap insulation and wrap the big line from the compreser to the dryer and on to where the A/C line goes into the firewall. wrap the dryer but leave the bottom open to let the sweat run off. The colder you can keep that line the colder the air out of the vents will be. I did mine and went from 56 degs to 47 degs out of the middle vent with the blower on the number 1 setting on any hot day this summer.

 

The first thing that you need to look at is to see if the compressor is even coming on and stayn on of if it keep cycling on/off could just be a simple cycle switch

 

Also check air flow. just had freightliner with plugged up air filter. would not cool with temps above 90.