Automotive Air Conditioning Information Forum

Hi,

My 99 Expedition front compressor seal was leaking so I decided to replace the compressor. The pressure of the system had dropped down to 15 psi. I pulled the compressor, the condenser and the front orifice tube. The front orifice tube was loaded with debris. So I replaced the compressor lines from the accumulator and to the condenser, the rear evaporator, rear tvx valve and the accumulator. I flushed the front evaporator and the lines running to and from the rear evaporator with half a gallon of mineral spirits then about 3/4 of can of four seasons flush.

My plan was to use denatured alcohol to flush and then four season flush as a final flush. I grabbed the wrong can and used the mineral spirits by mistake. I only used 3/4 of a can of the four seasons flush for the final flush of the above because everything coming out with the mineral spirits was clean. I didn’t realize it until the system was together and sitting under pressure with nitrogen. It is holding 75 psi of nitrogen. I plan to open it back up and flush the rear lines to the rear evaporator and the front evaporator with denatured alcohol and the final flush with 4 season flush. I haven’t run the system and the lines running to compressor and to the condenser from the compressor are all new. I will remove the accumulator during the flush.

My question. I don’t really have time to get to it until next week. Is it ok to leave it filled with nitrogen? Would you evacuate it and leave it under a vacuum? Is there anything else I should do?

Thanks!

Your "re-flushing plan" sounds good as long as you blew-out any remaining traces of the final flushing solvent.

I suggest replacing the condenser as well. The parallel-flow condenser on your vehicle acts like a system filter, but it can't be effectively flushed clean due in part to its many micro-passages. Moreover, most manufacturers and rebuilders require condenser replacement to maintain the compressor's warranty.

Best Practices suggest replacing the accumulator each time the system is opened.

Nothing wrong with letting the system sit idle while under pressure. It's far better than leaving it sit under vacuum, which will pull-in air and moisture should a leak develop.

Ok,

Thanks. I will let you know how it goes.

Update.

Opened the system up. Removed the new rear txv, the new rear evaporator and the new front accumulator. Flushed the rear hard lines with 1/2 gallon denatured alcohol and then 2 bottles of 4 season flush. Flushed the front evaporator with 1/2 gallon denatured alcohol and 1 bottle of 4 season flush. I captured all the flush in plastic bottles. Fluid was clear. I replaced the new front accumulator with another new accumulator. Vacuumed the system down and filled with nitrogen to 75 pounds. Evacuated it again. Filled with Freon. Seems to be working fine. Only have about 3 hours on it so far.

Thank you for the help.