omeezy

High pressure on low pressure ac port

11 posts in this topic

I recently replaced my ac compressor with a used ac compressor because the first one seized causing my belt to break. After the replacement i took it to an oil change chain to get the system recharged. While many people don't think highly of oil change chains i thought it would be a good idea to take it there since they have the tools to vacuum the system.  To keep it short, i am not getting cold air and while the ac compressor clutch is engaging, the low pressure port is giving a high pressure reading about 140 while the high pressure port is giving a low reading about 40. My guess is the AC Receiver Drier/Accumulator might be bad or clogged but i have no idea, i need help please. i already checked the fuse box and the relay and those seem to be fine. I also did multiple pressure checks to see if i had a leak somewhere but i wasn't losing any pressure. i was thinking to just buy a compressor, condenser and AC Receiver Drier/Accumulator, does anyone have any recommendations?

this is a 2001 626 lx 2.0

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What was the ambient temperature when you did this check?

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i checked the pressure multiple times and to be honest i didn't take the temp into account.

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Did the numbers change, or at least twitch, on the gauges when the compressor kicked on and off? I'm assuming that the compressor is engaging / disengaging periodically during the test with that question.

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the numbers only changed the first time after the ac button is pushed after that they just stay the same.

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Do you recall what the numbers were before the AC button is pushed?

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the high pressure was pretty much zero until i let out some of the low pressure then pressure on the high end went up, but i still had a high low pressure and a low high pressure i am not sure what that means.

one person (not a pro) who did look at my car said it seemed there was a leak on my high pressure port. while i don't believe there is a leak since the car does hold pressure, I am so tired of this problem not being fixed i wanted to replace that high pressure line and found out Mazda no longer makes it and it seems no one else does as well.

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OK - step by step:

1) Connect lines and see what the pressures are, with engine off (or at least no A/C) button

2) Engage A/C and compare new pressure readings

This is a decent chart to use for ideal pressures: http://rechargeac.com/how-to/ac-system-pressure-chart

If the numbers are closer together with the system off, like 60/90 or 70/80, and spread apart when it is on, then either your gauge is hooked up wrong (maybe the lines are connected to the wrong gauges, somehow?) or your Schrader valves got switched somehow. (The low / high should only connect to their own port, they are different sizes, as I am sure you already know.)

If the opposite is true - you might have hooked up the lines backwards on the compressor when you put on the replacement.

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I see! would this cause the ac not to blow cold air? also if the high pressure line is leaking, do you have nay idea where i can get a new one, i called mazda napa, orielly, autozone and baxters and none of them had it.

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Yes it most certainly would cause the system to not blow cold air.

From what I can gather, I don't think anything is leaking. If so you'd probably be to zero on both sides already. The recharge service should have checked for leaks before trying to service it, anyway.

I think something is hooked up backwards somewhere.

EDIT - To answer your question, don't be afraid to hit up a junkyard or two. But I still don't think you have a leak. Where are you located?

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Portland Oregon

The recharge service did tell me it did not have a leak, that's why they went ahead and recharged it. 

I did call a junk yard (foster auto parts) and they actually checked with a few of their partners for the part. 

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