# 4640 air cond



## mrfred (Jul 5, 2011)

How do I know if a new air conditioning pump is no good. System has been down for about 4 years and old pump was froze up. Replaced the pump, received dryer, expansion valve and flushed the system with the John Deere flush. Cleaned the cond. and evaparator. Drew a vacuum for bout 20 minutes. Tried recharging the system and after the second can pressures were in the vacuum side on the low gauge and high side was up to 300. Had the pump not wired to start charging the system then unhooked jumper wire and plugged in the fuse and tried another can and it melted the fuse and compressor got super hot to touch. Dealer said the pump had oil in it so I never checked. Could expansion valve cause this if the lines are still dirty and plugging it. Is there a inline filter available to install before the expansion valve if this is the case. Could the new compressor be bad and how would it act. Thanks to anyone who could help


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## Fedup (Feb 25, 2014)

Inline filter? That's what the drier is. That's why it's located ahead of the expansion valve. Could there still be contaminants in lines and fittings? Absolutely! A system empty for four years could have all sorts of such issues, from dry deteriorating hoses to aluminum oxidation on the inside of lines and fittings. Just how did you go about flushing the system prior to assembly? I use a pressure tank myself, and flush each line and component(except the compressor and the drier). In a case like yours I would do each twice, once in each direction, letting the air run for a while after to dry it out. What did you notice, if anything, when you looked at the inside of lines and fittings after the flush? Any brown or dark stain or residue?


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## Tx Jim (Jul 28, 2020)

I agree with Fedup that AC system will probably require more thorough flushing. IMHO evacuating an air conditioning system for 20 minutes that been out of service for 4 yrs is not near long enough evacuating time.


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## mrfred (Jul 5, 2011)

Think I will replace all the lines if there still available and flush the condenser and evaparator. Was hoping I wouldn't have to but I don't think I have a choice


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## Fedup (Feb 25, 2014)

You mentioned earlier that you had "flushed the system". So what did that entail? I'm guessing you missed something in the process.


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## Tx Jim (Jul 28, 2020)

Fedup said:


> You mentioned earlier that you had "flushed the system". So what did that entail? I'm guessing you missed something in the process.


I'm also interested is method utilized for flushing. Did you utilize the flush tool designed for flushing AC systems? What type compressor does your tractor have(Delco or Denso)?


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## mrfred (Jul 5, 2011)

Replaced all A.C. Lines and hoses, expansion valve and receiver dryer again and system is working excellent now


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## Tx Jim (Jul 28, 2020)

Congratulations on your repair & thanks for the update.


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