ac question

I had to replace the ac compressor on a 2004 dodge dakota .. I didnt replace nothing else.. ac work fine before the clutch burn up.. she not cooling at all with the new compressor.. when me and my friend recharge the system the pressure on the low side was way high and we shut it off..I put the compressor on myself I added pag oil which i was under the impression that it didnt have that much oil in the compressor.. my friend think I put too much in.. today I drain oil out of the compressor which I didnt get that much out.. I thinking I need to drain some out of the drier.. well I didnt vaccum the system down I went ahead and added freon it blew alittle cool with the one can and went back to warm with the second can.. what can i check to see what I did wrong? I donated this truck to friend who a vet that needed a better ride..

If you didn't pull a vacuum before charging, there's air in the system and it won't work correctly.

Well someone told me it would be OK so I listen.. I knew better..well just st wasted three cans..
Thanks!

Did you replace the Drier or suction Accumulator ? Sure I usually always pull a vacuum on them but I have done many in backyards for friends and charged the systems without pulling a vacuum on them and they cooled fine. Yes its the right way to do them but yours sounds like something else going on since you said the low side was reading high ? How high was it reading as they should run around 28 to 32 on the low side. Makes me think if the comp went bad that maybe it has something else that got in the system. Ron

With most newer vehicles when the compressor grenades you won't get away with just changing it out...Drier/accumulator replacement and checking the expansion valve/orfice tube for debris is a must as well as flushing the system...Then hope the condenser isn't clogged after all that ... Most new compressors will have a small amount of oil but more will be needed using the service manual's recommendation for your vehicle...All new compressor should be hand turned at least 10 revolutions to expel the oil into the system before use...Don't run it too long without out a system flush or you'll be buying a new compressor again when all the metal makes it's rounds through it..

The old compressor was clean .. just the clutch gave up..

The ac started blowing cold driving in the highway and stop when idling .. I'm never mess with ac just what I read or seen and taking advice from shade tree mechanic.. I pour the oil out of the old compressor and rubbed between my fingers it felt smooth.. I may go ahead and flush the lines and evaporate and condenser..

Does that have an auxiliary electric fan right behind the radiator? If it does I would check to see if it's working. Probably has a small transistor type relay that's probably bad. If it's cooling going down the road but stops when sitting still it doesn't have enough air flow across the condenser.

It is still a good idea to have the system evacuated before recharging. Moisture in the air can cause problems down the road.

The fan did stop working when the old compressor quit.. I did replace the coolant temp sensor.. I didn't see a bad fuse or relay.. I will check to see if the fan coming on..

It's called a relay but doesn't look like a traditional relay. I'm not sure exactly where it is on a Dakota but I normally find them bolted to the core support or frame rail behind the bumper, fascia, or headlight.

it cooling great but the compressor is kicking on and off not sure what causing that.. any suggesting i may have miss?

The system will come on and go off while using the AC, supposed to do that. But, if it does it in quick succession, on, off, on, off...that's short cycling. Usually a sign of not enough freon. These systems do not hold much, so getting in the correct amount is very important.You need to start from scratch....
make sure everything is flushed. You may not be able to fluch the condensor, most newer models you cannot. If the clutch is all that was bad, everything should work like it did. Make sure you are getting power to the clutch. What are the pressures? Low side should be around 30psi, high side (depending on ambient temp) around 150-200.
But, you gotta get all the air out by evacuating the system. You probably need to take it to a shop that has the correct AC equipment. Hope this helps! Jeff

Thanks! My friend wants to add a little freon and see what happen.. I thinking the high pressure cycling switch might be bad

Like others have said if you didn't pull a vacuum on the system, you have air in the system. It will never work properly until you pull all of the refrigerant out and pull a proper vacuum on the entire system. When the system is tight and a proper vacuum holds then you can charge it properly.