VW compressor fitting?

[Motohead1]

Hello all I am looking for a VW 1.8t AC compressor fitting. Its off a 2004 passat. I needed to make lines from the VW to 2001 dodge dakota. swap info can be found here. http://forums.tdiclub.com/showthread.php?t=465373
As you can see the suction side is an oddball large fitting. I tried to have a local shop cut and braze or weld the line so it could be swedged but the VW pipe is a strange alloy with a very high melt point. Any help would be appreciated.

[Tom Greenleaf]

Welcome. Link to VW site didn't show for me no surprise. If you have the line that will work then the right place with correct tools to put that end on shouldn't have a problem. I can't speak for high end welding of alloys (heliarching I call it {sp?}) but should rule out any 'brazing" meaning with brass.

If you are determined to have a hose made up to adapt to this job 1 is to find the right shop and have the parts. The tools for a good splice in a rubber section I'd rather see if at all possible not try to fit just the end on.

Have to ask why go to this instead of what would just fit in the first place?

Tom

[CJB]

I found a fitting here at the shop that's made out of steel that might work. Could you give us a measurement near the oring area. I'll try to get a picture posted of what I have

[Cornbinder89]

on the original VW line, how long is hard line before it changes to hose? What is the OD? My thought is to cut the line long and flare or double flare and using a union to beadlock hose fitting. I know you present line is cut short, but a replacement OEM shouldn't be too expensive if the solution will work.
I could see where Heli-arc wouldn't work if you don't know the alloy, you would need a filler metal that would mix/adhere to both the VW part and the weld on hose end.
If all else fails, take the stub end to a good machinist and have him make you one in steel, then silver solder or braze a steel hose fitting to it. I suppose he could duplicate it in aluminum as well, but steel is easy to weld/braze with common equipment, aluminum is more tricky.
It is do-able, you just may not be able to buy off the shelf a way to get what you want.
I have had to use the services of a good machinist a few times, the trick is to design what you want so you can repair yourself in the future if you have a hose failure. With steel you could heat and "un braze" the hose fitting and replace with another with just torches, the steel should last the life of the car, aluminum, might not.

[Motohead1]

Just search TDI dakota if the link is not working. No shop around here can weld it and these are good shops. The hard section in its original form hugs the compressor so tight a compression fitting cannot fit hence the cut and twist.


Here are a few pics. Please excuse the tape measure but as you can see this fitting is huge.





Having a fitting made might be the trick as I really would like to avoid fabricating a bracket for a compressor I dont have. But if the cost is crazy then I may be forced to do that.

[Cornbinder89]

What I was wondering was, before you cut the line to try and splice, was there enough solid line to flare? If so, than buy a new OEM line and cut further out and flare. Looks to be 3/4"/19mm line so could be flared to 3/4" fitting.
Another thought, if the base of the fitting is thick enough, could you drill out the tube and tap for a hyd type O ring fitting? I think it would be hard to make an A/C insert O ring fitting, but the Hyd type use a straight thread with a bevel at the top to hold and O ring, the problem would be the fitting would be large, for a 3/4, 19mm line The end of the fitting that the hose connects to would be JIC flare, but at the pressures we are talking, you could get way with an SAE flare fitting on the JIC flare. The main difference is the angle of the flare, JIC is 37 deg vs 45 deg for SAE.
I am beginning to think having a fitting made will be you best option, followed by a replacement compressor. It will come down to what skills you have and what you will have to pay to have made.

[Motohead1]

What I was wondering was, before you cut the line to try and splice, was there enough solid line to flare? If so, than buy a new OEM line and cut further out and flare. Looks to be 3/4"/19mm line so could be flared to 3/4" fitting.
Another thought, if the base of the fitting is thick enough, could you drill out the tube and tap for a hyd type O ring fitting? I think it would be hard to make an A/C insert O ring fitting, but the Hyd type use a straight thread with a bevel at the top to hold and O ring, the problem would be the fitting would be large, for a 3/4, 19mm line The end of the fitting that the hose connects to would be JIC flare, but at the pressures we are talking, you could get way with an SAE flare fitting on the JIC flare. The main difference is the angle of the flare, JIC is 37 deg vs 45 deg for SAE.
I am beginning to think having a fitting made will be you best option, followed by a replacement compressor. It will come down to what skills you have and what you will have to pay to have made.

There was zero room to leave the line the way it was. A cut had to be made. I have made some calls to a few smaller CNC fab shops in the area as the larger ones wont touch it. Hopefully I can get one of them to make me a fitting.

My other possible issue is this compressor is a variable displacement one and the dodge system was a constant. I am hoping I can get away with running it.

[Cornbinder89]

Any decent guy with a hunk of metal and a good lathe can make a fitting, doesn't have to be CNC made. Most CNC shy away from small jobs because the programing takes more time than the cutting that they charge for.
I have a local shop that makes stuff for me all the time, he has a few lathes and a mill, but a lathe would do it all for a simple fitting. I don't know where you are, but ask around at welding/fab shops for someone who can spin one up on a simple old lathe.

[Motohead1]

So I finally found a small shop that will make the fittings I need. My question now is will I need to change anything in the system since I am using a passive variable displacement compressor in a 2001 Dodge Dakota system that is made for constant? I should have the fittings made by end of the week.

[Cornbinder89]

I guess since you are going off in uncharted waters the thing to do is try it and see how it responds. A marriage of two systems is always a crap shoot. once it is together and running we can try and help address what comes up.

[Motohead1]

So we think we have the AC fix. Finally found a machine tool shop to make a few fittings for me. Just have to get lines made.

[Cornbinder89]

Sometimes it just pays to pay someone to make what you need, from now on if a hose needs to be replaced it is just a common hose with common fittings. It can be hard to think outside the box when you are looking for something ready made.

[Motohead1]

Got the AC lines made up and put in all new o-rings and receiver dryer. Its ice cold now.


The original servicing with the dodge compressor was 1.85 lbs My lines are a little bit shorter now so i only serviced it to 1.7 lbs with a new robinair unit. Its a cold day today only hit 75F today so really no need for AC but I noticed the compresssor was cycling on and off somewhat regularly and not sure if thats normal for this system. i need to put gauges on it and get some numbers.

[Cornbinder89]

My guess is that the Dodge has a CCOT system so cycling would be normal under low heat load. Line length: it would be hard to change length enough to have an effect on charge wt. Size of condenser change would be more likely to have an effect, but either way I doubt you would be off enough to cause a problem if you put the OEM spec in.
We are always interested in how things turn out, It lets us all learn from what you found out.

[Motohead1]

yep it has a Orfice tube its .057 in size according to the dodge manual. And I had no idea how the Variable displacement 7sb16c denso compressor would act so I didnt modify it at all. We havent had a hot day this week so will see how it behaves in a few days when its back in the 90s. I bet there is over 2 ft of hose length removed from the system now so thats why I put a little less in there. It does seem to put a load on the little 1.9 when I first turn on the system as you can here and see the turbo spool about .2 psi more to maintain idle speed.