Combines AC SYSTEM ON M2

[tbran]

I doubt the recharge oil is your problem. The only way to really diagnose your problem is with a set of gauges. See what the pressures are. High side should be about 150PSI PlUS the outside temp. Thus 200-275 range. low side should be 10-18PSI. Slightly high low pressure usually indicates moisture and high low perssure indicates faulty expantion valve. Inability to obtain high pressure indicates either a faulty expantion valve or rarely a faulty compressor. MAny compressors are unnecessarily replaced. It is imperitive to pull a good vacuum for at least 30 minutes. lowering the pressure to 28-29 inches of vacuum lowers the boiling point of water so as it is exhasted as vapor and thus leaving the system free of H20 which prevents the freon doing its job. NORMAllY 3.5 small cans will fill the system but we use pressures instead of weight to charge systems. Again follow the first set of pressures given to charge the system. It is very easy to overcharge R134a be carefull as too much is worse than not enough. let me add we have picked up R12 replacement from NAPA - I think it is Freeze12IJ - and it works great. Some of the propaganda about replacements are not true. I feel if a nationwide chain like NAPA endorses and sells a product for a few years it must be safe to use. Finally we also use a can of stop leak in all old systems

 

[mo]

I suppose if you vent the gas to the outside with the system runnig some oil would escape and then recharge but this not legal nor satifactory. The gas should be recovered. The oil level checked with a dip stick of clean wire which is inserted into the check hole on the side of the pump casting. Usually a 9_16 wrench. The wire is bent like so ). I think about 7_8ths inch is the number. Make sure the pump is level and the wire extends to the bottom of the chamber. If there is excess dismount pump and drain it. Hold it over your head and look up until the proper amount of oil comes out and you vow to never do that again. It might be time for a professional check of the system anyway. You can help yourself the most by making doubly sure the coils in the cab are clean.

 

[tbran]

high head pressure w_o cooling can also be caused by a plugged condensor core or a motor that is not turning.To check motors, with everything off spin one motor fan blade, the other should spin due to being motorized by the one you spun.

 

[brent_56]

The freeze 12 works great for me also I run it in both of my cars as well as my l2 and a 7080 and a 7020. It cools really well and i have had no trouble with the compressors while useing this in them. I think it is very good stuff!!! Brent

 

[silver]

discharge system, I would recommend removing large pressure hose from compressor, remove large hose up in cab, get a flush gun, use ac flush fluid, have someone help, wrap some clean towels on the hose in cab and flush, see if you get a bunch of crap out of hose, if you do compressor is junk, if not, you need to flush entire system, need to clean evaporator and condensor to make system work well, hope I'm not being to in depth, If your not the well experienced in a_c find someone that knows, don't cut corners, check hoses, look for oil leaks, wet hoses, darn clamps on hoses are trouble, make sure you have a good vacuum pump, a_c is not hard, just need to learn how it works, change expansion valve if system has been marginal, scott