AC in Daughter's 850

Craigd2599 · Post by **Craigd2599** » 27 Jun 2019, 04:45

Hey kids...
My daughter's 850 is giving me fits. The AC stopped working. I jumped around the low pressure switch and it worked so I figured I'd have a week or so to get the stuff together to fix it. On Monday, she was driving to work and heard a "pop" and the freon leaked out. Haven't had time to chase the leak yet but the pop sound seems mysterious. Would a high pressure hose blow like that? I know they have a pressure relief blow-off, could that have been it? Any suggestions on where to look first? As far as I know the entire system was replaced prior to me buying the car in late 2015

Post by **Ocelot** » 27 Jun 2019, 05:59

I know the high pressure hose/pipe in the area of the compressor can break due to rust. I don't know how to say it in proper English, my bad!

Post by **abscate** » 27 Jun 2019, 09:22

Ocelot wrote: ↑27 Jun 2019, 05:59 I know the high pressure hose/pipe in the area of the compressor can break due to rust. I don't know how to say it in proper English, my bad!

Engels is uitstekend !!

Klausc · Post by **Klausc** » 27 Jun 2019, 12:43

A serious over charge will cause the high pressure side valve to open, and 'bang' once. I did that once when I added two cans with the outside temp only in the mid 60's. Two days later, at 95F in the shade, the valve blew. There was still R134a in the system, enough to drive home with cool air, not ice cold.

Craigd2599 · Post by **Craigd2599** » 27 Jun 2019, 18:34

So you just recharge?

Post by **Roger_850T** » 27 Jun 2019, 21:35

So the right way to address this would be to put on a set of gauges and see what's actually going on before randomly throwing parts at it.

Does it still work? If the overpressure valve vented off a little extra charge, then stopped venting, then you may be ok. Gauges will tell you.

If it doesn't still work, maybe something failed catastrophically (i.e. went pop) and now needs to be replaced. If you find something with an improper hole in it, then that probably warrants replacement.

The 850's as they age run into issues with clearance in the AC compressor clutch - things wear, and the clutch doesn't engage properly, hence the "bread clip trick". It doesn't sound like this is your problem from the described symptoms.

There's always the chance that a hose or fitting failed. If you find a hole, fix it. Then evacuate, and if it holds a vacuum, recharge.

When you check it out, let us know what you find!

Roger

Klausc · Post by **Klausc** » 28 Jun 2019, 10:34

Craigd2599 wrote: ↑27 Jun 2019, 18:34 So you just recharge?

With a pressure gauge. No need to pop again...