850 AC - A different problem?

[David Taylor]

How do you change the air gap? I've got a VW Passat with similar

symptoms, and am planning tomorrow to try a bypass wire to test with a
solid 12+ volts. If it is the clutch gap, how would it be adjusted? (
Sanden compressor)

Incidentally, the clutch gap problem is usually only when it's very warm
say got to the 30 deg C type weather and it works for the first 10 mins
or so but then the extra heat increases the resistance of the windings
such that there's not quite enough magnetic force to pull the plate in
from the increased distance. If it's not working when cold then it's
unlikely to be the clutch gap.

David.

 

[Robert Lutwak]

Recall that our symptoms are that it works beautifully for about 10-15
minutes and then just blows warm air. When this happens, the clutch is
clearly not spinning.

Well, we had it at the dealer this week for the timing belt replacement (and
transmission flush), so I had them look at the AC too. Based on the good
advice from this board, I described all the symptoms and suuggested they
look at the overtemp switch and clutch gap.

The dealer determined that we need a new evaporator ($1350).

This seems unlikely to me, given the symptoms.

 

[Michael Pardee]

Recall that our symptoms are that it works beautifully for about 10-15
minutes and then just blows warm air. When this happens, the clutch is
clearly not spinning.

Well, we had it at the dealer this week for the timing belt replacement
(and transmission flush), so I had them look at the AC too. Based on the
good advice from this board, I described all the symptoms and suuggested
they look at the overtemp switch and clutch gap.

The dealer determined that we need a new evaporator ($1350).

This seems unlikely to me, given the symptoms.

I agree completely. Evaporator problems were legion for the 850 all right,
but they were pinhole leaks and produced low-refrigerant indications -
consistently poor cooling and short-cycling of the compressor.

Mike

 

[David Taylor]

The dealer determined that we need a new evaporator ($1350).

This seems unlikely to me, given the symptoms.

Agreed. If the evapourator has sprung the 850 leak then the refrigerant
would leak until it just didn't work at all. If it works for a while,
every day then it's not the evapourator!

David.

 

[David Taylor]

Recall that our symptoms are that it works beautifully for about 10-15

minutes and then just blows warm air. When this happens, the clutch is
clearly not spinning.

It's dead easy to measure the gap yourself, if you don't have a feeler
guage just go to any car parts place and buy one, then just select
strips until when pushed between the gap, they just bind.

It should be something like 0.3 to 0.6mm (or thereabouts), like I said,
mine was 1.2mm.

David.