Hey -

I own a 96 850 Wagon (non-turbo) and noticed that the A/C could be colder than it is.
I grabbed a can of 134a with the hose and gauge, and hooked it up. The first reading without anything on was very high. Perhaps around 80 or so?
I started the vehicle and flipped the A/C on high. The compressor continually kicks on and off, from around 28psi-40psi...ON...Off...ON...Off.
You can open the valve on the 134a and the gauge will show the psi rise. I let it up to about 60psi and shut the valve.
As soon as the valve is shut its back to 28psi-40psi. On...Off...On...Off.

Any suggestions?

thanks-

Josh

 

I'm guessing that the system needs to be bled and recharged, but I am no expert on A/C. I almost always take mine to somebody that has the equipment to diagnose the problem and recharge the system. I don't trust these kits we buy at an autoparts store.

 

I have had the same problem for the last year and a half and I've given up

I had the compressor clutch fixed, the pressostat replaced, the 134a level checked and nothing. It still cycles like you describe and if I am in the city, the compressor directly stops when I am at the stoplight. When I start moving it starts again.

 

OK thanks. I actually finished off the can, and now it doesnt cycle. It blows colder than before, but the gauge reads around 30-34psi with the A/C on full blast. Should I get another can?
What should my gauge readings be for:
Car On with A/C off: ?psi
Car On with A/C ON FULL: ?psi

 

I would bet money (not a whole lot though) that you will be needing an evaporator. Yours sounds just like mine did last year. The can lasted about a week then it needed more. I paid a guy $1200 to put in a new evaporator. My son in law and I are getting ready to do one ourselves. Probably within the next couple weeks. Looks like a whole lot of work.

 

I'd do it myself if I needed to replace the Evap. $1200 to install a $140 Evap is sickening regardless of the work.

I'm still waiting to find out the psi for the vehicle running with the A/C off, and the psi for it ON full blast.

You may be right, but I'm hoping its a very slow leak and the can will last longer than that. I've heard of them last a year or more after a recharge, and my vehicle is a 96 with 166k on it...so you never know.

 

From the service manual (no mention of A/C on or off during these measurements), I suppose that at these levels pressure sensors are sending OK signal to ECU):

SPECIFICATIONS

Compressor Type .................... Zexel DKS-15CH 6-cyl.

Compressor Belt Tension (1)

Compressor Oil Capacity ..................... (2) 6.8 ozs.

Refrigerant Capacity (R-134a) .................. 26.4 ozs.

System Operating Pressures (3)

High Side ............... 406-450 psi (28.5-31.6 kg/cm

)

Low Side .................... 25-33 psi (1.8-2.3 kg/cm

)

(1) - Belt tension is maintained by automatic belt tensioner.

(2) - Use PAG Oil (Part No. 11 61 407-0)

(3) - Pressure switch cut-out points.

 

Thanks for this info. I'd assume if I'm right around 30psi with it running, that I'm good then.
Kinda confused because I thought I saw past posts indicating it should be at 60psi

 

According to the Dealer Tech, the A/C at the low side should be 25-55psi
while the A/C is in use, should draw it down to around 25psi, and when it kicks off steady out around 55psi.

They also told me that this can be sketchy with the DIY recharge kits, as pressure in the system as well as ambient temp. can throw of the gauge reading - thus causing you to possibly blow something by over-filling. They suggest having the system drained, and refilled to capacity with a real A/C machine.

This would be around $165 at my local dealer.

 

Sounds a whole like what I said at 1:20 this afternoon when I replied. After I put in two cans in one week, I was afraid I would do more harm than good and just drove for a while w/o a/c. Until it just got too hot and I wanted to drive the car.

 

yup - sounds very similar.
my response on the volvospeed forum was what I was looking for though.
I'm within the allowable psi and its currently blowing cold...so to chance a blowout while trying to up the pressure would be pointless. Just crossing my fingers I'll get the most of what I refilled (i.e. - it's not a fast leak).
If it is, I'll stick to the 2-60 as opposed to 134a