Re: A/C Help Needed...

["Robert Rooney" <dmcvegas@xxxx>]

Sounds like you may have a clogged orifice tube. When you look at the 
hoses connecting to the compressor, notice how wide they are. Not too 
many places for any kind of blockage to build up. Evacuate the system 
and remove the orifice tube. It may also be a good idea to blow out 
the A/C lines to remove any dirt. Replace the orifice tube and have a 
pressure test run before evacuating the air and refilling with R-12. 
Since the system is sealed any kind of dirt inside is not normal. A 
pressure test can tell you weather you've got a leak in the system, 
or it wasn't properly evacutated last time.

Note: When we replaced the orifice tube on our car it came out easily 
in one piece, I have been told that this is not always the norm. If 
while removing the orifice tube it breaks apart inside DO NOT DRILL 
IT OUT!!! When the orifice tube is inserted is twists up thru a quick 
curve in the metal A/C line. If you attempt to use a drill to remove 
broken piece(s) you risk puncturing the A/C tube.

-Robert
vin 6585

p.s. after replacing the orifice tube & filling the system with 2.8 
lbs. of freon, the A/C never cycles on & off. I don't remember the 
pressures, but they never got up high enough from then on to trip the 
switch. duct temp was measured @ 42°



--- In dmcnews@xxxxxxxxxxx, "Nathan E. Green" <gzen21@xxxx> wrote:
Compressor works good, pressure builds to required level,
> then compressor cuts out. Normal. This goes on for a couple minutes 
and all
> is good, then compressor keeps going despite dangerous High 
Pressure values.
> We reached nearly 350psi before turning the A/C off for fear of 
busting a
> pipe. Turn back on the sytem...works good for a couple minutes then 
the same
> thing. So what's the problem?
> I am thinking we may have a bad high pressure switch that doesn't 
shut the
> compressor off properly?(But why would it initially work, then 
suddenly
> climb out of control??)
> A second more realistic solution is a clogg in the evac?