Air conditioner issue

[Dorfer]

My air conditioning stopped working about 4 years ago. The estimate for repair is $2200. Last summer i started adding freon to my volvo. My heat and air now blows on and off while driving. Freon only lasts about a week or so when i add it. I am worried i have caused more damage to my car. The evaporator needs replaced.

[polskamafia mjl]

Yeah, your evaporator needs to be repalced; and as you noticed it is expensive to have done at a shop. However if you are feeling motivated it can be done yourself. Next summer I am going to tackle this and finally replace my evaporator so my windows don't fog up when it's raining. lol

[falconbrother]

Can someone tell me more about the compressor gap thing. I turn the AC on and it works great for ten minutes or so, then blows hot air. If I cut the car off and then start it the AC works great, for ten minutes or so. The system has plenty of freon, at least the gauge reads that is has plenty. Any thoughts??

[Ozark Lee]

I put together a series of links that describe the clutch gap and the various methods of repairing it. It is pinned in the repair database. I would post links but I am on dial up at my cabin. I should be back in the city this afternoon and if you still haven't found the thread bump this thread and I will find it for you.

...Lee

[redsouther]

See attachment for a photo from another post that I edited. The red arrows show where I inserted the plastic shims. Note that this is not likely to be a permanent fix. I removed all of my old shims this past weekend, and had to insert new, thicker shims in order to get the gap down around 0.2mm.

My best guess is that the flat metal rings are deforming over time due to pressure from the plate and shims. either that, or the plastic shims are melting/compressing under the heat. (Although the old shims didn't show any signs of this).

[Retired MVS Contributor]

Pressure gauges cannot tell you how much "freon" (R-134, really, not freon) is in the system...The gauges can only tell you the high and low system pressure is at any given time under a given temperature...The static pressure (engine not running) will vary WIDELY with temperature...If the compressor is not running and the outside temperature is 30 degrees, the static pressure will be about 28 pounds... With exactly the same conditions but with outside air temperature at 90 degrees, the static pressure will be about 100 pounds...This does not mean that the system is either undercharged or overcharged, it simply means that there is some liquid refrigerant in the system...It may not be enough, or it may be too much...

If you have a 40 pound bottle of R134 and the temperature of the bottle is 70 degrees, the pressure in the bottle will be 75 pounds, regardless of whether the bottle is full or almost empty...Don't be fooled into thinking you know how much refrigerant is in the system based on the static pressure reading...

The loss of cooling after a short time can be any of several things including a restriction in the system that is elevating the pressure, but the most common in systems where DY'ers have added refrigerant is overcharging, resulting in a high pressure shutdown...Checking the compressor as soon as that happens will tell...If the compressor is not running, there is a good chance the pressure is too high...If you jumper the high pressure cutoff switch at this time and the compressor starts, you can be sure it is overcharged...DO NOT!!! leave the jumper connected, serious damage to the compressor or bursting of the evaporator is possible...