New A/C compressor will not build pressure

JESSE11JAMES

MEMBER
1999 VOLKSWAGEN BEETLE
2.0L
4 CYL
2WD
AUTOMATIC
214,000 MILES

I just replaced the A/C compressor and expansion valve and receiver dryer flushed and pulled vacuum and started to refill with r134 and the low and high sides both sit at 45 PSI. Compressor clutch engages and fans turn on but there is no pressure difference between low or high side.

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

Hi,

If the system held a vacuum and is fully charged, the compressor is likely no good. If you are showing 45 PSI (equalized pressure with the system off for at least 1 hour) and there is no change when the compressor is running, the compressor isn't working. The only other thing I can think of other than a bad compressor is if even though the compressor clutch engages, for some reason it isn't turning the compressor. Do you notice the center of the clutch/pulley assembly turning when it engages?

Also, here is a link you may find of interest:

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Watch to see if you see the center of the clutch/pulley turning when engaged and stopping when it disengages.

Let me know.

Joe

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Monday, June 14th, 2021 AT 9:38 PM

JESSE11JAMES

MEMBER
2 POSTS

Yes, the clutch is engaging. I work on cars a lot but not usually A/C systems and this would be the first time I have had a defective compressor strait out of the box. I'll try to exchange it and see if a new one works.

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Tuesday, June 15th, 2021 AT 5:38 AM

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

If the pressure doesn't change, something must be wrong with the compressor. If possible, let me know what happens when the compressor gets replaced.

Take care,

Joe

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Tuesday, June 15th, 2021 AT 8:42 PM