[Vwdiesel] 2000 TDI a/c question - and a brief description of

LBaird119 at aol.com LBaird119 at aol.com
Mon Jun 7 07:52:04 PDT 2010

In a message dated 6/7/2010 7:17:50 AM Pacific Daylight Time, 
dieselwesty at yahoo.com writes:

> I do not think this gauge needed would be anything special for Automotive 
> AC, so as long as I can get my diesel compression tester to properly 
> connect to the high side nipple, that should work, yes.
> For the lost side, I can use my normal gas engine psi tester, the one I 
> use for beetle motors and stuff.
> My Questions.
> Do I take the PSI readings with the car cold or warmed up and running?
> How much do I rev. the motor when putting in the 134a, about 2K
> How will I know the can is empty, will there be condinsation on the 
> outside to show or something like a propane bottle?

  Buy or borrow a set of A/C gauges.  You lose enough just through an 
old set of R-12 vintage gauges!  The new ones  have smaller hose ID 
like a GOOD diesel compression gauge.  High side isn't critical unless 
you have a blockage type of issue going on and know what you're 
looking for.  You have to have a set of 134a adapters for the gauges 
as well.  They generally have schraeder valve fittings on them and 
you need the quick couple-to-schraeder adapters.  High and low 
are different sizes.
  Freon goes into the low side.  It always says to keep the can
upright but I do it upside down at an idle.  It's slow enough to keep 
from slugging the compressor and about 10 times as fast as going 
in with vapor.  Just have someone hold the throttle around 2k to 3k 
while you disconnect so that you suck every bit you can, out of the 
can.  (higher rpm, lower pressure on the low side, to a point.)  Don't 
take your time to disconnect though.  If it's still a little low on freon, 
your low switch will cut off the compressor and pressure will come 
back up in the can, higher than at idle.
  It's fairly hard to find the fittings to adapt from the A/C fittings to 
what you may have also.  Tried doing that to put propane in one 
system and use my gauges to do it.  Ended up deciding hose and a 
clamp was the only thing I could find that would work!

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