Barrier Hose Questions

[jrobie79]

Barrier hose question:

1991 318is, think I have all the r134a conversion in place (o-rings, parallel condenser, expansion valve, etc).

Charged the system with r134a and oil, compressor started smoking so now I'm currently waiting for my replacement compressor.

While digging a little more I wanted to confirm my soft hoses are barrier hoses (supposedly 87+ are) however the two sets of hoses look different:

Hoses coming off compressor:


Evaporator hoses:


From what I read the barrier hoses have the spiral wrapping as seen on my evaporator hoses, but the compressor hoses look different. When I enter the part number for the compressor/condenser hose the product images look like they have that spiral wrapping, while the ones in my car do not....I wonder if the PO fucked with the system before hand.



thoughts?

[TobyB]

I see a 46-90 date code in the bottom pic (46th week of 1990) and I bet if you clean
carefully and look at the other hoses, you can find codes on them.

That said, an old, crusty and very knowlegable AC tech said, when I asked him about this,
that an old R12 hose will almost always hold R134. It's a NEW R12 hose that will leak.
He said their success rate with R134 and old hoses was so high, they never changed them.
On the rare chance they leaked, they fixed them at their own expense.

Anecdotal, I know, but 3 of 3 conversions on my junk have held well enough...

t

[jeffnhiscars]

The EPA has a bulletin about this...basically says that the mineral oil that r12 runs with will saturate the hose and improve its ability to keep r134 from leaking and therefore it was not mandatory to upgrade hoses when converting. Having said that, my experience was that the 2 hoses I did not swap (above the glove box) went from a slow seep for the first couple of years where I had to top up the system 1-2x/yr to being completely porous and requiring replacement.

That suggests to me that the old hoses can work...for a time.

I also don't think BMW started using barrier hoses until at least 1990-1