99 V70 XC AC Compressor fix ??

PatternFlyer · Post by **PatternFlyer** » 12 Jun 2010, 16:05

Ok... it is time to figure out how to fix the AC going on & off problem.

I've seen other fixes on the gap, but mine has different look that I can't figure out how to.

Anyone know?

Should I try to add shim in the gap? (arrow pointed)

Thanks,

Retired MVS Contributor · Post by **Retired MVS Contributor** » 12 Jun 2010, 17:40

Do you mean that the compressor clutch is cycling on and off every 30 seconds or so?...If so, this is caused by the suction pressure limit switch...The pressure is too low and it is doing what it is supposed to do, it is protecting the compressor from damage due to oil starvation...It usually means that the system needs a boost of refrigerant...

There has to be some liquid refrigerant in the system for it to work...It is the liquid changing to a vapor as it is released through a small orifice that causes cooling...No liquid, no vaporaizing...No vaporizing, no cooling, and nothing to circulate the compressor oil and keep the compressor from seizing up...With R-134 the static pressure will be close to the ambient temperature...If the temperature is 80 degrees and the static pressure is 85 or so, there is some liquid in the system, but not necessarily enough...On the other hand, if the ambient temperature is 80 degrees and the static pressure is 50 pounds, you can be sure there is only vapor in the system and no liquid so it needs recharging...

PatternFlyer · Post by **PatternFlyer** » 12 Jun 2010, 21:02

I meant the AC working for an unknown length of time and starts blowing wet & not cold air. When it works, it sure is cold.

I think it is because of the compressor becoming hot or the gap is too large. I measured it and was about .91mm while it should be under certain amount.

Since the AC compressor gap fix PDF shows different compressor, I am stuck.

Retired MVS Contributor · Post by **Retired MVS Contributor** » 13 Jun 2010, 07:01

I never heard of this "shim" fix...How does one keep them from being hurled away by centrifugal force?...

Post by **Pauloil** » 13 Jun 2010, 07:50

either take it in and find out if you have a leak
or put a can of freon in it. like jerrymac said: "It usually means that the system needs a boost of refrigerant..."
for like $20 you can get a hose nad a can of freon to connect to the low side by the ps compressor and put gas in here, i.e., hold the can of 134 upright. don't add leak stop. I have a 95 850 and put in can of freon last yr for the same thing you are describing, and I am still O.K.

Retired MVS Contributor · Post by **Retired MVS Contributor** » 13 Jun 2010, 18:33

Hold the can UPSIDE DOWN...Every can of R-134 I ever saw tells you that right on the label...When the can is held upside down, the vapor pressure is above the liquid and forces the liquid out of the can and into the system...When it is held upright, only vapor enters the system and you have to wait a long time while the liquid off-gases and gets sucked into the system as a vapor...The only time you do not want to add it as a liquid (as in some older systems) is if it is added directly into the suction port of the compressor...In a process called "slugging" the compressor cylinders will fill with liquid and since liquid cannot be compressed the compressor will be damaged...

Post by **polskamafia mjl** » 13 Jun 2010, 19:14

If the AC is cycling on and off your problem is a lack of refirgerent and possibly a leaky evaporator. Refill with R-134 and see how long the system holds a charge. If it is upwards of a month then your evap core is ok for now. If it is significantly less than a month then you need to replace the evap core.

Post by **taxi** » 16 Jun 2010, 17:19

Maybe i can help? I just looked at my "shims" and removed a few, with good results!
If your problem is: "working fine first 10 minutes, or maybe half our, then not at all until the next cold start", you need to remove one or two shims!

Im writing this because i recognized the compressor, i have one just like it so I know you just have to remove the center-bolt, then put three 25mm M5-screws/bolts in the holes surrounding the centerbolt to press it off, and the shims will probably just fall out! The gap of the outer clutch-disk should be 0,3 to 0,5 mm, mine is now 0,05 mm (think i lost a shim along the way there) but its working. Make sure you know how big your gap is before you remove shims, annoying if you don´t..

If i missunderstood your problem, feel free to ignore me! (Please ecsuse my english writing-skills)

Post by **Ozark Lee** » 16 Jun 2010, 18:33

(Please ecsuse my english writing-skills)

You are doing just fine!

...Lee

Post by **JRL** » 16 Jun 2010, 20:42

NEVER hold it upside down.
What you do is have a pail of warm (not too hot) water. Lie the can in there, the warm water will allow the R134 to enter the system at the correct, (slow but not THAT slow) interval.
If you get a GAUGE (duh) to hook up the can to, you will know if you are charged fully or not.
If you are full it IS most likely the compressor clutch.
I've filled 5 cars in the past 6 weeks, I've gotten pretty good at it