Hey everyone. I would like to know what the known ac issues are for the 420a. What mine is doing is when I was trying to a some freon to the system, the upper ac line would jump violently every time the compressor would kick on/off. Eventually the ac protect mode would kick in and turn off the compressor. It acts as if there is a clog in the system somewhere even though it spent a good 3 hours on a vac.

Beings that summers is over, I went ahead and parked my car for the fall/winter for some things that I want to do to it. Getting the ac working properly is one of those thing that I would like to take care of before next summer (it's hot in FL). What are some of the things that I should start looking at to fix this issue?

Any help would be appreciated.

I know that I could get a whole kit from rock auto but I was really wanting to know if anyone had any incite on what the common things to replace would be ( dryer, expansion valve, etc.). Like I said, I would really like to get this ac system working before next spring. It would make driving in the summer here in FL more tolerable.

I'll take any and all ac gurus advice please!

You really just need to make sure nothing is clogged in the system anywhere.

Sorry that I don't have anything more useful to add, but there's nothing special about our A/C systems. If worst comes to worst, any A/C shop should be able to handle the issue.

it would be best to check for a clog, make sure the compressor turns over freely by hand with the engine off, you may feel some resistance which is normal; but binding and abnormal noises aren't good signs for a compressor. make sure there isn't too much refrigerant oil in the system, too much oil can cause a lot of a/c problems. usually when i do an a/c system service i always performance test the system, check the amount of freon that is in the system and compare it to manufacture specification, check for leaks from any of the components and then recharge the system if no problems were found. if parts do need to be replacece, for example a compressor becomes defective, always replace the compressor the expansion valve, whether it be an orifice tube or thermal expansion valve, the dryer/accumulator and flush the lines and condensor and evaporator. on most newer cars today it's more difficult to flush condensors it's become a newer practice to just replace the condensor core instead of trying to flush it due to it's newer designs and configurations. when you do flush a system always distrubute the amount of total pag oil the system calls for. for example, the system takes 8 ounces of pag 46 oil. i would put two in the condensor, two in the evap core, 2 in the compressor, one in the dryer and one ounce in the a/c lines. doing so will distribute the the oil and prevent any hydraulic lock up in the system if you add it all to one spot. plus it allows the oil to circulate with the freon more quickly in an a/c system with new components.

other than all that there really isn't any major faults or known problems with our 420a a/c systems that i'm aware of.