V70 Air Con: Aircon not working - compressor?

[reggit]

Just a quickie;

Just had the car an Halfords (was impressed with their service btw) for an aircon pre-service and refill if all went well - it didn't! It only worked for a couple of minutes the cut out, hence why I took it in.

They've verified the system isn't leaking, but the compressor isn't building pressure properly although it is switching as expected.

I've very briefly read something about clutch on the compressor needing shimming.

Is this DIY-able, or am I better looking for a new (low mileage used) compressor pump?

The one on mine is around 203,000 miles and 15 years old.

[ThomasG]

Diy-able, definitely.

Took me half hour.

Pair of long nose pliers, flat screwdriver, small zipties (50p at toolstation)

And a safe way of crawling under the front of car- I use ramps.

But before that- check do you actually need shimming.

Typically:

Gap is to big (if you can slide in your debit/credit card, its too big)
Aircon works from cold start for few minutes, then stops.

If symptoms are different- chances are you need different fix

[Brendan W]

This is only one of a number of threads about the options
https://www.volvoforums.org.uk/showt...Fc+clutch+shim

[oragex]

As above, I'd look into the clutch gap first, and maybe inspect the pulley bearing because it must be really worn by 200K miles.

But why do you say it's not building pressure? Did they measure the high side and it wasn't high enough? The compressor may simply be worn for some reason.

Maybe bring it first to a good A/C specialist.

[reggit]

They told me the pressure readings, but I’ve forgot what they were. I think high side wasn’t building pressure. Told me the usual problems on this age Volvo is the clutch shim. I’ve never done work on a/c before so thought I’d consult the good people of the forum :-)

I’ve checked the bearings recently when chasing down a squeak on the aux belt - it actually turned out to be the belt! A cheap nasty one the previous owner had fitted

[oragex]

Maybe have a look at the a/c clutch. If it's engaging every 5-10 seconds or so, the gap should be fine and there may be a different issue.

[reggit]

It engages and stays in, but seems like it may have a shim issue.

It was cooling for a few minutes before cutting out and I’ve just just a credit card as a crude feeler gauge and it slides in with room to spare.

[cheshired5]

You can check the ac pressure in Vida.
You can also get live data of the ac relay, evaporator temperature, cabin temperature, recalibrate the climate system...... Basically, get Vida on it.

[reggit]

Originally Posted by cheshired5

You can check the ac pressure in Vida.
You can also get live data of the ac relay, evaporator temperature, cabin temperature, recalibrate the climate system...... Basically, get Vida on it.

I nearly could do, but it was purged today - think it's got nitrogen in it now for the testing. Forgot to ask though tbh - but they didn't put refrigerant in as it failed the testing.

It should still work though, so I'll shout at the vida computer a lot - was going to re-install to see if I can get rid of the annoying WSL pop-up - and see what it reads.

[oragex]

Originally Posted by reggit

It engages and stays in, but seems like it may have a shim issue.

It was cooling for a few minutes before cutting out and I’ve just just a credit card as a crude feeler gauge and it slides in with room to spare.

That sounds indeed like a gap issue, as it gets a little warmer the clutch magnet can't make up any long for the large gap and it disengages. The gap should be very thin, just enough so as not to have friction between the pulley and the clutch plate when the plate is not running. Credit card thickness is indeed way too much.