[Vwdiesel] 2000 TDI a/c question

[LBaird119 at aol.com]

In a message dated 6/3/2010 8:27:55 PM Pacific Daylight Time, 
sshourds at flash.net writes:

> As best I can tell, the manual specs are for 203 psi on the high side 
> and 17 psi on the low whilst running at high cool.  I borrowed some of 
> Dad's time and gauges and we found 155 on the high side and 40 on the 
> low side.  Sadly, there's no sight glass.  We looked hard and with all 
> the time I've spent in the engine bay of this car, I would have found 
> it.  Believe me.  The a/c's still dropping out on me after a while.  
> Good to start and after 40 minutes or so, not as cool anymore.  I'd 
> assumed it was the evaporator freezing up because of low coolant, but 
> adding coolant barely changed the readings and the sweating in the seat 
> feeling.
> 

  Really rare (from what I've seen) to ice up a car's evaporator.  
Might do it if the cabin filter is really dirty (have you checked it?)
  Other options are moisture in the system, freezing up the expansion 
valve or a poorly operating expansion valve.  There are others but 
not sure they have any screens like Chevy has.  Make sure the 
fan runs and kicks into high speed.  Usually does in higher ambient 
temps when the coolant pressures (and volume) are near correctly 
high.  Too low and the fan runs on low.
  Moisture is fairly common but usually not enough to cause problems.
You have to drain the system, get new o-rings and replace the 
reciever/dryer then reseal, pump it down good, then refill.
  If that's the case, come on up and I can pump it out for you!  ;-)
     Loren