Let's talk barrier hose,..please?

[dshepp806]

Greetings to all....


I called my wrench today to schedule an AC charge for my 89.. Having reviewed the historicals, I'm right on schedule for a recharge (R12),...she appears to need annuals.

The Wrench, in conversation as to hoses, commented that it was all "bullsh@t" (as he put it) and that the system was under enormous pressures,..usually manifested at the fittings....I was floored that he didn't partake in barrier vs. non-barrier hose discussion.....maybe he already understands that mineral oil has "filled" the spec'd holes in non-barrier stuff..we're talking R12 here, guys.

Whatzup with his comments?

I mentioned I would present him (next year), with all hoses replaced with BARRIER hoses and a new drier (probably an upgraded compressor...),..asking him to evac and process. I was met with this "observation" of "a waste of time",..quite taken aback by it.....I don't need a frikin history of why they didn't need AC in Germany and that this was an add-on for US...geeeze,..I'm past that,..I'm looking at all deficiencies, as revealed by the knowledgeable folk here on this group...


Any observations here?

As well,..do any of you have actual spec sheets on non-barrier hoses used on a 89? Leakages per linear foot,..however they might spec it.......do they spec the "hole" positions?

As well,..specs on the barrier hoses used within current aftermarket hoses?

Thanks guys!


Best,

[Jim Sims]

I will conjecture the mechanic doesn't want to do the dirty, awkward and potentially frustrating job of running new hoses and then leak checking the system.

See SAE standard J2727.

The pressure is manifested within and at the hose, fittings, compressor seals, condensers, expansion valves, etc. not just at the fittings. Real world and laboratory tests show that non-barrier hose leaks (through the hose material) at about 9 times the rate of barrier hose. Systems using barrier hoses (recall that most vehicle A/C systems use a small fraction of the hose used in a 911) show about equal leakage through the hose and at the fittings (10 to 15% contribution each) with the compressor accounting for most of the system leakage ~60%. Leakage would really be minimized if an electric motor powered hermetically sealed compressor (like in a household refrigerator) could be used but first vehicle electric system voltage will need to increase - I believe Europe is headed in this direction.

[dshepp806]

Thanks, Jim. Hell, I mentioned that I would take on the task of hose routing for the barrier install,...whatzup with that? We'll do the grunt work (at least: TRY)

It will show up next year with brand new frikin' hoses, new drier,...let's get it done, eh? At least, phase one!

Thanks for the SAE standard J2727 spec,..just what I needed///// ....some leak data. Your guidance is logged.

My best,