[xj-s] A/C questions

'86 XJ-S
It’s getting hot in S. Fla… Adrianne’s A/C does not produce any cold air.
There is a leak somewhere and I’d like to locate it, but I do not want to
add any freon because it’s way too expensive and I have it in my head to do
a 134a conversion. Maybe.

I only checked the low (suction) side pressure at 2K rpm, ambient temp. was
87 F. The pressure was 20-21 psi. It’s supposed to be about 31-34. The
lines that are supposed to be cool are just as hot as everything else in
there. The electric fan starts when the A/C is switched on, and the blowers
work, too.

I also noticed the expansion valve is just barely visable in a hole in
the firewall, looking at it from the engine bay. Would this mean I would
need to remove that dashboard in order to get to it?

Any collective thoughts on the most likely place for a leak? I may be able
to borrow a leak detector, but I’m not sure now if there is enough pressure
in the system.

If by some strange coincidence a heat servo-thingy is not functioning, is
there a way to manually defeat it for a while? (I came to no conclusions
about this while following last week’s excellent thread about the servo
motor). This is not the problem, but I’d like to make sure I don’t have
this to contend with while doing the other checks.
TIA
Best,
Harry

'86 XJ-S
It’s getting hot in S. Fla… Adrianne’s A/C does not produce any cold air.
There is a leak somewhere and I’d like to locate it, but I do not want to
add any freon because it’s way too expensive and I have it in my head to do
a 134a conversion. Maybe.

Two things. I’ve been in SF last week, and while browsing through an auto store,
I saw a (and bought) a R12 -> R134 conversion kit. You have to withrdraw
all R12, then srew on two special (non-removeable) R134 fittings, and then
add two cartouches of some “stuff”. You do not need to evacauate your system,
as it was not opened, and you do not neat to replace oil, O-rings what-so-ever
(says the description) Then you simply add R134. I paid about $30.00 for the kit.

The same company also provides a bold on cartouche with some redish fluid which
will leak out and help to find the trouble.

  • Matthias>

I only checked the low (suction) side pressure at 2K rpm, ambient temp. was
87 F. The pressure was 20-21 psi. It’s supposed to be about 31-34. The
lines that are supposed to be cool are just as hot as everything else in
there. The electric fan starts when the A/C is switched on, and the blowers
work, too.

I also noticed the expansion valve is just barely visable in a hole in
the firewall, looking at it from the engine bay. Would this mean I would
need to remove that dashboard in order to get to it?

Any collective thoughts on the most likely place for a leak? I may be able
to borrow a leak detector, but I’m not sure now if there is enough pressure
in the system.

If by some strange coincidence a heat servo-thingy is not functioning, is
there a way to manually defeat it for a while? (I came to no conclusions
about this while following last week’s excellent thread about the servo
motor). This is not the problem, but I’d like to make sure I don’t have
this to contend with while doing the other checks.
TIA
Best,
Harry

Two things. I’ve been in SF last week, and while browsing through an auto
store, I saw a (and bought) a R12 -> R134 conversion kit. You have to
withrdraw all R12, then srew on two special (non-removeable) R134 fittings,
and then add two cartouches of some “stuff”. You do not need to evacauate
your system, as it was not opened, and you do not neat to replace oil,
O-rings what-so-ever (says the description) Then you simply add R134. I paid
about $30.00 for the kit.

The above description, while common, seems to me to contain a contradiction.
You do not have to evacuate the system, yet you do neet to withdraw all R12.
How do you remove the R12 if you don’t evacuate the system and don’t open the
system?

The discussion about O-rings continues. Normal O-rings don’t mind R134a,
except that they don’t swell as much as they do with R12. As a result,
marginal seals with R12 may leak with R134a. Special O-rings sold as
designed for R134a and in some fancy color like blue or olive green are
really made of the same black stuff, they are just a little FATTER and dusted
with colored chalk to indicate the difference. For most stock systems, you
can just put in R134a and it’ll work fine. But keep in mind that it MIGHT
leak, especially at the compressor shaft seals, and you therefore might have
to correct those problems.

Since R406a/HotShot is now approved, I am at somewhat of a loss as to why
people would still consider converting to R134a.

– Kirbert | If anything is to be accomplished,
| some rules must be broken.
| - Palm’s PostulateFrom: mfl@kernel.paris.sgi.com (Matthias Fouquet-Lapar):

Harry Trafford traff@ICON.HMSD.UFL.EDU:

K> Think about HotShot or R406a too.

Good idea. I’ve never seen it, though.

Supposedly, does not require a conversion, just charge it up. You do have to
install fittings, though, due to some regulation that no two types of
refrigerant use the same type fittings.

I also noticed the expansion valve is just barely visable in a hole in the
firewall, looking at it from the engine bay.

K> You’d better hope not! I had no trouble replacing mine from the engine

compartment. Just remove the crossover pipe and a coupla other things
getting in the way.

Nope. That’s where it is. I followed a small metal line on right side
and large hose on left to the hole, inside which, is the expansion
valve. I didn’t pull on it.

Something got edited. I KNOW that’s where it is, what I was saying was that
you don’t need to pull the dash to replace it; it’s replaced from the engine
compartment side.

K> Back end of the compressor. Where ever, it should be covered with oil –

that’s what the A/C guys look for

Yes! I sprayed choke cleaner on it to clean it. I’ll look again tomorrow to
see if there is any more oil weeping.

It might not, you may have already lost enough charge that no more leaks out.

It couldn’t be that easy, could it?

Sure! The damn O-rings on the pipe connections at the back end of the
compressor seem to be a prime place for trouble. The plate that holds the
pipes in place – under the cruise control bracket – is not strong enough,
bends when tightened, and the O-rings leak. Usual advice is to replace the
compressor while you’re there, and use new O-rings. I put a coupla big
fender washers in the stack, and replaced the bolt with a high-grade stud and
nut to be able to apply serious torque without worrying about the threads in
the compressor.

– Kirbert | If anything is to be accomplished,
| some rules must be broken.
| - Palm’s Postulate

The above description, while common, seems to me to contain a contradiction.
You do not have to evacuate the system, yet you do neet to withdraw all R12.
How do you remove the R12 if you don’t evacuate the system and don’t open the
system?

I’m not sure, but should not simply open the circuit get out all R12.
(I am still pissed, since I took my car to a garage to get compressor, hoses
receiver replaced. I could have done this myself, but being envrinment friendly
I liked the shop to save the R12. Well the guy there simply vented it into
the atmosphere. When I questioned it, he said, “We don’t have the required
equipment”)

The discussion about O-rings continues. Normal O-rings don’t mind R134a,
except that they don’t swell as much as they do with R12. As a result,
marginal seals with R12 may leak with R134a. Special O-rings sold as
designed for R134a and in some fancy color like blue or olive green are
really made of the same black stuff, they are just a little FATTER and dusted
with colored chalk to indicate the difference. For most stock systems, you
can just put in R134a and it’ll work fine. But keep in mind that it MIGHT
leak, especially at the compressor shaft seals, and you therefore might have
to correct those problems.

The package I saw contains two cartouches of mistery contents which are
supposed to take care of the sealing issues

Since R406a/HotShot is now approved, I am at somewhat of a loss as to why
people would still consider converting to R134a.

I guess it’s not really available

Message text written by Matthias Fouquet-Lapar

Since R406a/HotShot is now approved, I am at somewhat of a loss as to why
people would still consider converting to R134a.

I guess it’s not really available
<

just for the record, it is available here in New York. I don’t know about other
areas-

						jb

At 06:24 PM 6/2/97 -0400, Harry Trafford wrote:

'86 XJ-S

If by some strange coincidence a heat servo-thingy is not functioning, is
there a way to manually defeat it for a while? (I came to no conclusions
about this while following last week’s excellent thread about the servo
motor). This is not the problem, but I’d like to make sure I don’t have
this to contend with while doing the other checks.

You can stop the servo in any position (assuming that the temperature
control/amplifier will move it) by unplugging the amplifier, or removing
the fuse in the amplifier supply lead.

If the amplifier will not drive the servo to the position you desire, a 9V
radio battery applied between the red and purple wires on the servo
connector (disconnected) will drive the motor in either direction.

As a longer term solution (cheaper than a new amplifier), a double pole
switch (like a window lifter switch) can be arranged to drive the servo
manually.

regards,

Mike