They really do have holes in them!!!

[adamnitti]

I just got a couple of replacement A/C hoses for my car. I had heard mention of the 'pin holes' in prior threads that supposedly leak freon on purpose. GEEZ... You can see these little holes plain as day!

Now I really regret spending the money on these, because it seems as if I am now taking leaks for granted! :-) Seems I should have gone to an A/C shop and had some barrier hoses made, instead. They are not cheap, either.

[pwd72s]

"I had heard mention of the 'pin holes' in prior threads that supposedly leak freon on purpose. GEEZ... You can see these little holes plain as day! "

Adam, it's probably a German Government plot to create global warming, thus allow the "greens" to take over the planet. Actually, since my first ever Porsche, I have not a clue why, but the Germans seem to be allergic to rubber products. They can't make 'em decently. Hoses, belts, or seals. Doesn't seem to matter. The USA and Japan both do better when it comes to rubber pieces. Anybody out there know why?

[Doug Zielke]

Originally posted by pwd72s
...... I have not a clue why, but the Germans seem to be allergic to rubber products. They can't make 'em decently.......

Paul, you (obviously) have never owned an Italian car. Looking at my old Alfa Romeo, you'd think the Italian rubber factories were on strike 364 days a year!!

[jlex]

I'm really surprised to hear that, Adam. I thought I had read that it was only the earlier models that used the pin-holed hoses. Aren't the later model cars using barrier hoses? I'm wondering if you ended up with something that's been on the stock shelf for a long time...
Maybe you should look into barrier hoses & see if you can return those you've bought. Something doesn't sound right here.
regards,
jlex.

[R22tech]

Dude, You've gotta be kiddin' me! There's got be something to that. Maybe we can pressure test them to see at what point they blow the charge.

[adamnitti]

Originally posted by R22tech
Dude, You've gotta be kiddin' me! There's got be something to that. Maybe we can pressure test them to see at what point they blow the charge.

yeah, it's weird all right. i'm thinking about returning them if they are going to bleed.

[R22tech]

Adam, I thought I read something about Porsche using this "pinhole" or pin-head technique as a protection against high pressures. The 911 is the only car I know of that you have to close the "hood" while running the a/c. This is because you would essentially have a "failed" condensor fan motor with the hood open, which would lead to extreme high head pressure. I bet those hoses can handle 200psig without leaking, which is more than enough for a properly working system. It would be interesting to test that and could be done. The only thing is: will it ruin the hose if we do? I still think you should stick with the factory hoses-but that's just my opinion.

[Roland Kunz]

Hello

Yes the pinholes are a "seafty device" witch will avoid bursting the noses or send the condensors to heaven.
This was a reaction to such accidents with the hoses used in the first generation ( Those where the red Aeroquip).

The hoses themself are made for much higher levels then average hoses in those years but they aren´t barrier type hoses.
As far I remmeber I only had seen them on Porsche 911 and Mercedes with secound rear AC system ( Well that was a protection car ).

Over the years when the hoses get old they will bleed but the outher layer will hold up the pressure yet the bleed holes will bubble out to lower the pressure by volumechange.

This is also a simple sign to show old lines or failures in the system to the mechanics.

Grüsse

[pjv911]

A proper running system should have aprox 25-30 psi on the suction hose and 190-230 on the pressure hose. The hoses used on most A/C systems are rated for 600 psi and will definetely let go if they are old. This info is for r-12 systems. THE R-134a systems run slightely higher pressures(about 20% higher). Those pressures are for a 60-90 deg day

[adamnitti]

Originally posted by Roland Kunz
Hello

Yes the pinholes are a "seafty device" witch will avoid bursting the noses or send the condensors to heaven...
Over the years when the hoses get old they will bleed but the outher layer will hold up the pressure yet the bleed holes will bubble out to lower the pressure by volumechange. This is also a simple sign to show old lines or failures in the system to the mechanics.

roland, thanks for the info. can i safely assume, then, that under normal operation, these hoses are not going to bleed until they get old?