Volvo Maintenance Hints for 7xx/9xx - Bill Garland's Nuclear ...

illustrated instructions at its website. Check and replace the orifice valve in the high pressure
line connection on the passenger side, not at the evaporator connection. Perhaps a variable
orifice valve is called for, but I get 32-34 degrees Farenheit air at the vents with the factory
orifice valve. Change the accumulator if it has been there for several years or many miles or
lines were left open more than ten minutes so air got in. Otherwise, Volvo says it can be
changed every second or third time you open the A/C lines. Put in at every connection you open
brand new R134 O rings (yellow, not black) lubricated with either mineral oil or an applicationspecific,
silicone-based lubricant instead of PAG or POE oils. (PAG or POE oils should not be
used due to their hygroscopic nature that can promote moisture attraction, possibly causing oring
deterioration or thread fitting seizure.) Draw a vacuum of 29.7+ inches of mercury for at
least an hour. Check that the system maintains that vacuum after you turn off the vacuum pump.
If you use Johnsen's R134 refrigerant in liquid form (you turn the can upside down rather than
hold it upright like with Dupont Sava R134) preferably with UV dye, the vacuum in the system
sucks in a can or two right away. As soon as you start the engine, suction from the compressor
will suck a third can. That is 36 ounces rather than the 32 ounces called for the A/C on the 960.
That works for me, but I remember Tom Irwin recommends a small food scale to put in exactly
32 ounces of R134. If you have to change the condenser, I found the direct fit aftermarket one
from FCPGroton has the advantage over the condenser that was in the car (Volvo?) of no steel
plates against the aluminum. Otherwise, that aftermarket condenser is a bit shorter top to
bottom than the one that was in the car, with round rather than flat tubing. I cannot compare
capacity (BTU) between the two condensers, but so far that aftermarket unit gives me 32-34
degrees Farenheit air at the vents in the tropics!
Useful Air Conditioning Parts, Products and Tools. AScanTech (Avantia) direct fit aftermarket
condenser is $175 from fcpgroton and a Volvo one is $439 from Swedish Engineering. A new
(not remanufactured) Sanden SD7H15 compressor is $320 from FCPGroton. Locally, I was
quoted $995 (yes, $995) sight unseen so I do not know whether it was new or remanufactured.
An accumulator will cost you $50 from FCPGroton and maybe a couple of dollars more from
Swedish Engineering. A Mastercool flush gun is $43 and flushing solvent is $20 a bottle from
www.ackits.com You will need shop air to use those. The Airsept kit with screens to keep debris
in the system from getting into your new compressor costs $67 from www.jcsonlinetoolshed.
com. For leak detection, get an Airmax LED penlight for UV leak detection from http://www.keepit-kool.com(costs
about $40) and a set of UV-enhancing glasses from JC Whitney for about $5.
You can purchase air conditioning dye injectors from NAPA. The glasses are necessary to see
the dye. To seal pipe joints with o-rings, get some Nylog, which is compatible with the o-ring
material and prevents corrosion.
Poor A/C Performance: Diagnosis. [Inquiry:] I have a 1993 945 turbo. The air conditioner
(134a) works ok on the highway. when it is less than 90 degrees outside, but only makes the car
bearable in city driving. I checked the charge level and it appears to be fine. Does anyone have
any ideas? [Response: Abe Crombie] I had a car like yours and the a/c was fine in the
southeast US summer. The problem could be any one of several possibilities like heater valve
not being closed at full cold position of the temperature control, partially blocked condenser,
cooling fans not working correctly, etc. The only way to know you have the right charge level is