Hello everyone,
A mechanic told us that the car needed a new compressor, along with condenser and expansion valve. I couldn't afford the 1.5k they wanted so i bought the parts myself to fix it. The compressor clutch looked like it melted. I removed it, the condenser, and the expansion valve and flushed the two lines that run between them. Before the low pressure side was higher than the high pressure side. low pressure at like 100 and high at like 50. When i replaced all the parts the same scenario is happening, what in the world should i do. I am not a mechanic please let me know if there are specific things i should look for to make sure i can get this ac going. Thank you and let me know if you need more info to help me out!
Are you saying the static pressure (that is, pressure with AC not running) is different on the high and low sides? If so that indicates a blockage in the system since the pressure should equalize after the AC is off for a a while. That would usually a be few minutes, wait an hour to be sure.
You didn't mention replacing the drier. Hopefully you just overlooked mentioning that. Ditto for evacuating the system with a vacuum pump, and hopefully you put in the appropriate amount of PAG oil for the replaced components.
Other than that, you said the old compressor clutch looked melted which suggests that the compressor seized up. If that is the case the condenser needs to be replaced as well since compressors contaminate the AC system with metal debris when they catastrophically fail. Unfortunately the parallel-flow condensers used in R134a systems cannot be successfully flushed out. You would also need to replace your evaporator if it is a parallel-flow type for the same reason. You will probably find that the warranty on the new compressor requires that those parts be replaced.
Check the old compressor to see if you can turn the crank smoothly and easily by hand. (Not the clutch pulley but the clutch plate connected to the compressor crankshaft as in the photo below.) If it is locked up then your answer is likely that you still have contamination in the AC system.
i bought an ac compressor kit that came with everything, to my knowledge the drier comes with the condenser, so its integrated, i did vacuum the system. I will add that the oil that came out of the compressor was very new looking no debris idk if that indicates it was okay but I'll put that out there. the compressor also came prefilled with oem spec pag oil. yes the low pressure side is much higher than the high pressure side. Where should i start looking for a blockage? so the compressor, expansion valve, condenser with drier have been replaced and the system holds the vacuum i ran the vacuum about 45 mins and left it alone for about 15 and it was still at same vacuum. also, static and while running, the low pressure side is higher and high pressure is lower it doesn't change at all but when i went from vacuum to fill it up the high pressure side started to increase then stopped at about 60 and the low pressure side would get very high very quick. thank you for your great input as well!
If the oil from the old compressor is clean you may be OK on that score but I would still check and see if it is seized up. A blockage can be almost anywhere, and what makes things more "interesting" is that it is pretty common for new parts to be defective, especially aftermarket parts. If you can safely run your compressor (no debris in system and pressures not so crazy as to cause damage), Scotty has a video where he shows how to find blockages with an infrared thermometer. Sometimes if the blockage is in a hose you can feel a sudden temperature difference along its length just using your fingers.
https://www.youtube.com/watch?v=ajcD90Ll_Ik
thank you ill update this when and if i figure it out, might end up having to take it to mechanic but they want to charge so much! it's understandable but I simply cannot afford.
Okay, guys, love to learn and this was such a stupid fix. The compressor obviously comes with plugs that you remove once you install. The high-pressure side had a second plug that I didn't see after I installed it and removed the first plugs. thanks for all feedback but AC is fixed now.
Hey, that's great! Better something like that rather than finding out there was something serious going on.