V2Rocket

While my engine is out of my car for frame repairs I figured I'd knock out some other projects too.

I recently developed an AC leak and I had just replaced my condenser, dryer and one of the rubber lines so I figured it was one of the other original (R12) lines leaking the R134a out.

What puzzles me is if I can use a simple compression fitting on the existing hard lines and attach new o-ringed hoses or if I need to cut and weld a new fitting to the hard line? These lines see between 50-250psi in normal operation.

Pictured are the two lines in question, the feed for the compressor and the line from the condenser/dryer to the AC blower.

944Ross

There is a shop that does hydraulics and such in my town, they normally silver-solder or braze a new fitting on. They could easily put a new crimp-type or AN or whatever you want. I'm sure SoCal has plenty of places that can do that. Compression fittings like Swagelok are rated very high pressures but it might be hard to find ones that fit the tubing correctly (ID/OD).

Mike C.

Bingo Ross. I've been down that road (tried to find metric compression fittings). I ended up cutting off the old fittings and silver soldering new crimp fittings onto the original tubes (which are steel). I then cut new R134 hose to the original lengths and had a shop do the crimping for me. I bought most of the hardware here: http://www.docsblocks.com/ and was happy with them.

944Ross

Mike, at some point I believe you were going to try to re-create 85.5+ A/C lines (or at least the routing); did you ever do that? I'd be interested how it turned out.

Mike C.

I didn't Ross as I didn't have (or have access to) a good tubing bender. I ended up re-using most of the original tubes but did modify the compressor inlet fitting so the fill port was more accessible (still from under the car but better than on the compressor). I don't have a photo but could take one if anyone is interested.

joejoe

I would be interested in the modification.

xsboost90

the larger (suction) line runs at about 25 psi normal operation. Technically you could run some hose clamps.

944Ross

I assume you're talking about an R-12 system; an R-134a system is around that when the compressor is running, but with the system at rest it's around 70.

Mike C.

Correct.. The pressure in the system will equalize over time. It is referred to as the static pressure (the hi and low gauges will read the same). There are special fittings available that use hose clamps (I think even GM did it that way for a few years in the 60's) but I wouldn't do it that way. BTW, sliver soldering is not hard to do. I used a bottle of MAP gas (available at plumbing supply stores, etc.) with a propane torch tip.

V2Rocket

silver soldering it is, cool. now to find fittings and a shop to build me some hoses for less than an arm and a leg

V2Rocket

bump, can anyone definitively tell me if the 944 AC lines are in SAE or metric sizes? i am thinking SAE as earlier this year i put in an aftermarket condenser that was sold with SAE fittings and the porsche hoses went right on and didnt leak.

Mike C.

They were metric on mine.

V2Rocket

The nuts I know are metric, but the actual connections where the o-rings go, metric?

944Ross

V2, is your car Early or Late?

V2Rocket

early. just pulled all the original ac lines off the car and it uses SAE hose...


about an hour ago i pulled off the original upper heater hose and it had a ford logo and part number on it, but its identical to the porsche hose..