[Vwdiesel] A/C Compressor?

[lbaird119 at aol.com]

Well...
I didn't fully recharge it  since it holds 40oz.  I figured I'd throw in one can and see.  It SHOULD start up, suck down to about 25psi, high side start climbing and then kick off from low pressure.  Instead, it brought up the high a little, low went down a little (20 to 30 psi maybe?) and kinda hovered there with the compressor still running.  Pretty much what it was doing before I evac'd and changed the expansion valve except a few psi lower.  It was around 70psi before and around 40psi after, with it under charged.  Since the gauges didn't move like they should, I didn't put any more freon in there to reclaim back out.  Had enough fun of that for the day!  I also didn't pay real close attention to the readings on the gauges since they weren't moving right.
  It DID hit about 500psi when we first connected gauges to it.  Next glance and it was coming down and never went up high like that again.  Maybe 120 tops?  Low side was in the 70 - 90 range, warm day and maybe dropped 15psi with higher rpm.  
  Didn't notice much change in pressures with fast idle or higher, over regular idle speed after.

  I found that 180 psi is about where you end up with on the high side when you think all is close. But if you go to 220, when it's above 90F ambient, the second speed of the fan kicks in so the condensor cools better and the system actually see,s tp work a bit better even though it's not as cold, due to higher low side pressures.
     Loren



-----Original Message-----
From: James Hansen <jhsg at sasktel.net>
To: lbaird119 <lbaird119 at aol.com>; vwdiesel <vwdiesel at vwfans.com>
Sent: Sun, Jul 1, 2012 7:18 pm
Subject: RE: [Vwdiesel] A/C Compressor?


If you're making 600# the compressor is working.
top before you kill something, burn the clutch, smoke a belt, etc.... at
east your high side protection is working...
rom my limited experience, the most likely culprit is a broken dessicant
ag in the receiver-dryer.  A dessicant pellet gets as far as the expansion
alve, and plugs the orfice.
an you see into the receiver dryer window for flow? (tiny window in the
ine above the dryer?)  I'd evac, remove the dryer, check for loose
essicant, flush and clean as necessary with straight isopropal alcohol
eplace the dryer even if it's good, evac overnight or at least hold a vac
or 4-5 hours to get all the water and alcohol out, then recharge and see
hat's up.  Should need some oil too... have to kind of estimate that as to
hat you take out with the dryer...
IIRC, our B4 ranged from 35-40 on low side, 180 on high, but NOTHING
eplaces a recharge with a known weight of freon.  These low volume systems
re real finicky about how much is in there.  2005 Passat holds 600g of
34a.  You pretty much need to measure that in from an evac, hard to judge
t right by gauge behavior.  I have so many systems here with the farm
achinery, I got a robinaire recovery/recharge unit.  Saves many many
eadaches, yet there are a couple units that are just filled with gremlins.
james
-----Original Message-----
rom: vwdiesel-bounces at vwfans.com [mailto:vwdiesel-bounces at vwfans.com] On
ehalf Of lbaird119 at aol.com
ent: July-01-12 10:03 AM
o: vwdiesel at vwfans.com
ubject: [Vwdiesel] A/C Compressor?

ell, warm weather is here (then gone, then  here...)  So the wife wants the
/C to work.  It halfway pooped out as we were coming home, through NV.
urn it off a bit, then on and it'd blow cool for a while until I'd turn it
ff, wait then back on.
 Eventually I paid the ransom and put a can of 134a in it.  It didn't
eally help.  Took it to a friend that I borrow stuff from and has done me
ood on diagnosing stuff that flusters me.  Pressures were too high
overcharged) and not really doing much.  He concluded the expansion valve
as the culprit.
 Yesterday I pumped out 4 an da dab cans of freon (one blew the relief out
f the bottom so there went one can of salvage!)  I changed the valve and
-rings except for one wrong sized one they sent, recharged it and poop!
ow side drops about 10psi or so, when it kicks on.  Compressor stays
unning, low doesn't drop, high doesn't climb.
  So, what's the consensus, bad compressor?  Never had one before.  Anybody
ave a good one sitting on a shelf, to fit a B4 Passat?  :-)
   Loren
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