98 v70 a/c blows warm

spgstudent · Post by **spgstudent** » 08 Aug 2016, 19:35

So my v70 is in need of some a/c help. I vacummed and charged the system, started the car and the ac worked great. Well at least for a few minutes, cycled off and wont cycle back. I jumped the low pressure switch and no change, I had to do the bread clip mod (running used sm zip ties) bc the gap was out of spec and still no change. Im at a stopping point for the evening and was wondering what the next step would be. I haven't tinkered with the thhermo switch yet. Any opinions?

Post by **FlyingVolvo** » 08 Aug 2016, 20:27

Check the pressure and see if it's low. If it is, you may have a fast leak. If recharging it again fixes the issue again for a few minutes, try again with some UV dyed freon and try to see any leaks with a black light. If it's the evaporator (usually the culprit at this age), it's gonna be a pain DIY or an expensive repair.

spgstudent · Post by **spgstudent** » 09 Aug 2016, 05:16

I let it sit under vacuum for 15 min with no leak down detected, obv can only see low side pressure but ill check it again and if that's not it undo thremo switch and go from there

Post by **abscate** » 09 Aug 2016, 05:27

The one place you can't check is the low pressure side valve , of course.

Try leaving it under vacuum for three hours, and see if it bleeds in. If you lose charge in one day, it won't hold vacuum

Post by **erikv11** » 09 Aug 2016, 08:35

Really sounds like a clutch gap issue, what is the gap after bread clips?

spgstudent · Post by **spgstudent** » 09 Aug 2016, 16:10

gap is .357mm. I have not had a chance to recover Freon and check to see if its holding pressure again but ill be doing that before i leave work. Its 95 degrees out and Im dying on the way home without it

spgstudent · Post by **spgstudent** » 09 Aug 2016, 16:18

low side pressure gets to 43 lbs before compressor kicks off and low side pressure goes back to 90 psi- compressor will not kick back on

spgstudent · Post by **spgstudent** » 09 Aug 2016, 17:09

I recovered 1.57 lbs out of the car, i didnt have the time to let it sit for 3 hours and see if it leaked down, but did pull vacuum and it held for 15 min. Charged the system to spec and started car, pressure was around 36 lbs and compressor was on, well at least for a few minutes then turned itself off. both lines coming and going from compressor are room temp, and compressor is warm. Any ideas guys?

Post by **Ozark Lee** » 09 Aug 2016, 17:46

Hmm - 43 PSI on the low side is toward the top end of the actual operating range on most days and 36 PSI is dead in the expected range. The low pressure cutout usually shuts things down at about 28 PSI. How long does it run before it kicks out? Does the low side line get cold back by the low pressure cutout during the time it is running?

...Lee

spgstudent · Post by **spgstudent** » 09 Aug 2016, 18:06

It blew cold for a few minutes in the shop then shut off and I had to stop there as it was closing time. On my way home it worked for a solid 20 minutes blowing ice cold. But yet again it stopped working. By the time I got home it was too heat soaked to tell if it was cold. I will try and check it after it cools down some or in the morning