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

ecause moisture may damage the drier. Since I was replacing the compressor too, my
parts supplier suggested a new drier. Might be something to consider with a new evap
anyway.
4. Remove right side sill trim, side panel, panel under glove box and the glove box.
Removing the dash is not really necessary. Doing this job is much easier if you remove
the front passenger seat, then lay some padding down on the floor.
5. Disconnect control module cable (clip), remove control module (2 screws), and its
mounting bracket (3 screws)
6. Disconnect electrical connections to blower and resistor (3 plugs). Remove 3 screws to
remove the blower.
7. Remove approximately 9 screws around front, side and back of the evaporator housing.
Note that 740's/760's/940's/960's may have different evaporator housings so the number
of screws and procedure may vary. What you are trying to remove is the lower half of the
duct which extends from the cylindrical portion containing the blower going to the left to a
point where you may see a label for the evaporator. Coming down vertically from this
point, underneath, you will see 4 circular grommet-looking things. That is the other end of
the lower housing you will need to remove.[Tip from Gary Hammett] My 91 940 turbo had
more than 9 screws on the cover. All were evident with the exception of one on the upper
right side of the drain tube section next to the firewall and buried in the foam padding.
Most of the screws faced downward, but this one faces outward toward the passenger
door. Because I did not see it, I broke the plastic when pulling the cover down, which
could have been avoided by first removing the glovebox to see the screw. Being
extremely patient and flexible is a vital skill. Make sure you find all the screws because
they are hard to find, particularly near the firewall. I used a combination of sockets (7mm),
ratchets, flexible socket driver, and bought a cheap box wrench and bent it into shape to
be able to get all the screws out. When you have all the screws out, gently pry the lower
half off. This may require a little bit of force, because there is very sticky mastic sealing
the lower half to the upper. It may be a little difficult to tell the difference between mastic
and a screw, but if you leave a screw in and break the duct, you’ll have to install some
more screws to get a good seal when reinstalling the housing. I found that I had to install
some new screws anyway, because various parts of the housing broke anyway, and
plastic doesn’t seem to care for having screws removed and reinserted. I had to oversize
some of the screws to get a good bite. [See Tips below.]
8. Pull out the old evaporator and install the new one. Add compressor oil to the new unit in
the correct quantity. Transfer the filter and rubber seal from the old evaporator to the new.
This will require cleaning the old filter and gluing on the seal. I used duct tape to keep the
nuts from sliding down the pipes while installing the evaporator. Also, this will take some
trial and error to get the evaporator up into the housing high enough to get the threaded
connections at their proper location in the engine compartment.
9. Remove all of the old mastic with a flat-blade screwdriver and replace with new. It's sold
as windshield sealant, and it comes in 20' rolls at AutoZone. I bought 3/8" diameter
sealant and stretched it until the diameter was appropriate for the A/C cover. I also put a
bead of silicone around the drip tube foam where it contacts the firewall. Replace the
lower duct housing, blower, electrical connections and trim (See Tips below).
10. [Notes from Adam/Randy:] It is hard to get the lower housing back in place [see Tips
below]. The problem is that the back of that lower cover (nearest the firewall) needs to
slip over the evap, which has a pipe loop hanging at the lowest point. That pipe loop