I've come up with a fairly foolproof method to replace the hose on the long line that goes from the dryer to the expansion valve.....with the line and the engine in the vehicle. This hose is one of the three rubber hoses in the 928 A/C system and is the source of a huge percentage of A/C leaks. If the fittings rotate in the hose....the rubber hose has shrunk and leaks. If you are converting to R134a, the original hose is porous and will leak Freon. (Virtually all of these hoses leak, at this point in time.)

Because this hose is "hidden" behind the C/D unit (or the coil in the later model vehicles) it is frequently overlooked or ignored.

Here's a picture of the hose, out in the open (the engine was removed for this picture):



The repair is applicable to all vehicles equipped with the brass line that the low pressure fill valve is attached to. Later model vehicles have an aluminum line....we are working on a repair for this line, also.

The repair consists of removing the C/D unit (or coil) and exposing the line. Using a cut off tool, the original line is cut. At this point, the brass portion of the line line can be moved out, away from any wiring and paint. A new fitting is then silver soldered (low heat) onto the original line (and onto the original end fitting for the dryer) using a torch or MAP gas. A supplied hose (PTFE lined hose with crimped ends, covered in protective heat shielding) replaces the original hose section.

Here's a picture of the completed repair and the replacement hose (again, this picture was taken with the engine removed, for clarity):



The end fittings that are now supplied on the replacement hose are now black, to blend in better with the rest of the vehicle.

This hose repair is very simple and very easy, for anyone that can do minor welding. It can easily be accomplished in a couple of hours (while drinking a beer and talking to your buddies). Ask anyone that has changed (or attempted to change) one of these lines in the vehicle (with the engine in place) and they will tell you what a time (and money) saver this is.

The entire kit is 169.00. It includes the silver solder that is needed to attach the new fitting onto the line (and end fitting at the dryer.) The kit is currently available directly from me, 928 International, 928 R US, and 928 Classics.

 

That one is a pain in the ***.

 

You removed an engine to take a pic? Wow.

 

Aside from the low pressure hard line running from the expansion valve to a soft line going to the compressor (lower one in your pictures)

I have a soft line running from the condenser to the expansion valve in my 81 which was pretty easy to replace.

Was this a change when they added the fuel coolers?

 

Great solution, Greg. Thx for the effort.

I know this is likely a leak source on my GT, as the ferrule on the dryer end had previously been cut off and there are 3 hose clamps in its place... a very attractive patch job.

 

And you are saying the fitting can be made look less conspicuous?

 

He's got a long way to catch up with you ... you reduce whole cars to shrapnel to take pics

 

When you say earlier models with the brass line...what year range is that? I think my '86.5 has the aluminum lines, correct? You'll probably have that one ready by the time I've taken care of the rest of my AC system :-(

 

I changed that line on the car - it wasn't hard, but it did cost me almost $500 to buy a portable hydraulic bubble-crimp tool for crimping AC lines

(but I also had 3 S4's myself, and a couple of local friends who needed the job doing too, so for me it was worth buying the tool).

 

with engine in the car? how many parts did you remove? line and connections unhooked?........

 

Yes.

Certainly not an issue with that rear fitting hidden under the C/D unit. However the fitting on the front can be seen, if you look very closely between the radiator and the chassis.

No doubt **** overkill....however my brain has a minor siezure event when I see that "clown blue" on a 928.

 

I've never seen a rubber hose running from the condensor to the expansion valve. Pretty sure that rubber line was a prior repair job....probably to fix the leak at this hose.

However, that would work also....with the only downside that running a rubber hose that close to the exhaust should "cook it" fairly quickly.

 

That was a great repair, too! I'm impressed that you got the head of that portable crimper down into that area!

I believe that all of the S4 vehicles have aluminum lines, correct?

 

Great stuff Greg. Thank you.


Looks a little different here!




I assume that applies to this one too?




Are you saying they will hold R12 but not R134a?

 

Yes, even if the hose ends are tight and don't leak at the connection. Apparently, R134a has a smaller molecule. The A/C hose manufacturers had to come up with a different hose to keep the Freon from leaking out. You will hear the term "Barrier Hose", which was specifically designed for 134a.

I "solve" the entire issue, with this kit. PTFE doesn't care what Freon is used (or what fuel....or what brake fluid....I like to say that when we are gone and almost every trace of humans has deteriorated back into the earth, the cockroaches will have their homes and nests inside old PTFE hose.