My 88 740 Turbo was retrofitted some years back with 134a AC system. I believe it included a new compressor but I wouldn't know for sure. I tried recharging the system today but the only low pressure ports I found were on the compressor itself, backside. Using an adapter I could attach the 134a hose to the port closer to the left fr wheel well (vs the port on the same plane but a few inches away twds the engine block). I couldn't get the hose fitting onto the latter port because it is too long to fit onto the port and hits the left fr shock/strut (?) housing.

Just for ***** and giggles I tried pumping the 134a into the left side port I described on the compressor and then the accumulator, neither of which worked. I got pressure readings in the red (Warning) zone so I stopped.

I had the front end up on ramps looking for another port along the line anywhere but found nothing.

Thanks for your help.

 

Most of the time the low pressure port should be on the accumilator.

Thats how I always charge them.

 

And that's the big cylindrical silver thing located just fwd of the firewall on the left side (facing the engine), correct? The port on the accumulator is the wrong fitting for my recharger but if I remove that fitting, with it's one way valve like on an inntertube, I can screw on a fitting to accept the 134a fitting. However, when I disconnect the charger all my 134a shoots out until I can cap it w.the old fitting - i.e. the adapter has no valve in it to prevent backflow.

You think my setup is siply different than yours/others? I'd have thought these things all go the same way....?

 

I think someone messed with it and put a funny adapter on it.

Most adapters for the low pressure side you remove the schrader valve before you install the fitting.

The one that is on there sounds like it migth be a high side fitting.

 

Is it possible that your system was converted to a different gas than R134? If so they would have unique fittings. There are several refridgerant blends on the market that are alternatives to R134.

One would think that if this were the case, there would be a prominent tag or sticker indicating what to use. One would think. [&:]

 

Possible, yes. Never thought of that. There is rumored to be a sticker that came off some time ago that my brother (who had the car at the time and had it retrofitted) says he put in a file with all the car stuff. Time to dig it up...

 

I know what you are talking about. I have an 88 with the retrofitted package too. I'm in the process of trying to recharge my system. I'm asking the same question. But, I can clarify for the other users what you are asking.

With the retrofitted kit, the low pressure port is usually between the radiator(for mental image purposes), and the condenser. The only connection that fits that description is on the back on the condenser. Very tough to get to, but to me, it is the only one you can use. The connections on the left side of the engine bay(facing the engine) are all high pressure ports. If you are getting pressure readings in the red on the back of the condenser, from past experience, you do not need to recharge. You may need to discharge, seal any leaks (doesn't sound like you have any), then recharge. I personally believe the port on the back of the condenser is the right one. Anyone disagree with that?

 

The fittings on the Accumilator are low pressure fittings. All fittings on the bigger lines are low pressure fittings. The fittings on the small are high pressure fittings.

 

Right. The smaller lines are on the left hand side of the motor near the accumulator, like you said. With the retrofit kit, the larger line(there is only one going from the compressor to the firewall) does not have ANY connections on it. The only connection on or near the larger line is actually on the back of the compressor, I've never seen one like that before. Beyond that, all the other connections(1) are on the high pressure line. Like I said, I've never seen one like this.

 

I had an idea, it's worth a shot. I don't like posting links to other automotive sites on here, but there is a site just for Auto AC. Might be worth a look. If I ever get a reply to my query, I'll post it here.

http://acsource.net/acforum/viewforum.php?f=1

 

The port is on the back of your compressor. I had a friend look at mine today (all he does is auto AC all day long), he said that is the low-pressure port. Just thought I'd pass that on to you.

 

Thats because someone didn't do the retro properly.

There is supposed to be a port added to the accumilator when converted.

 

No joke. That I didn't know. I was actually told that it isn't uncommon for the retrofit kits to come with the port on the compressor. But, if it was put on wrong, that would explain the pressure in the red on her AC system.

 

Yes it would. The Volvo retro kit has a pipe to replace the pipe from the evap to the dryer.
Some shops just put the low side adapter to the accumilator.Thats where it is supposed to be.
They might have the adapter on the wrong side on the compressor.

I had a 88 that was retrofitted that I worked on today.The adaptor was on the accumilator.I had to slide the coil out to connect to the adapter.