Okay in an attempt to take a short cut I took the 85 300SD ( conv. 134A years ago) to a gas station and they were going to top up the a/c. After I drove down the road it got warmer in the cabin. I stopped and looked and there was
134 oil leaking from the plastic cap on the lo side quick disconnect. I carefully removed the cap and a small metal Pin rose up from the center and I realized the valve had failed. That said I am familiar with a std schrader valve and know the internals can be replaced. This newer valve has a plastic sleeve in it that looks like it has an internal head head design for unscrewing and installing a replacement. Is that true or do I need a whole new hose with the lo psi quick disconnect ? If it is replaceable it should be a .98 cent piece easily replaced.
Is my assumption correct ( yeah ! yeah ! I know when you assume something you make an Ass of U and Me)
Alan

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Probably depends on the type of conversion fitting.

My low side conversion fitting actually left the old schrader valve in the old R-12 port - it was basically just a collar for the 134-style adapter. But the adapter was threaded for a schrader. You should be able to just unscrew the old schrader and replace, you may need a longer schrader adapter than the standard tire valve.

But - you'll need to evacuate the 134 first - or find the thread about the "don't evacuate swap your valve gizmo tool" that was on the forum a few weeks ago.

Yak, Thanks for the info. This setup has the lo psi side hose and a valve body
built in to it.It still looks to me as though a new valve can be inserted. I have beleive all the 134 has come out from this failed piece.
I see you live in San Antonio, great town. I used to stay with my Aunt & Uncle
north of there near the Y.O Ranch.
Alan

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92 500E Silver 66k
82 Porsche 911SC 84K
68 Cadillac ( Gone Now )
03 Suburban Z71 200K
85 300SD 217k From Original Owner ( Dad )

You need a special shrader valve removal tool for this. I would just replace the whole fitting though. Especially if all the refrigerant has vented anyway.

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I need to see the cost of the hose and weigh that out. By the way the 124 in you Avatar looks great !
Alan

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92 500E Silver 66k
82 Porsche 911SC 84K
68 Cadillac ( Gone Now )
03 Suburban Z71 200K
85 300SD 217k From Original Owner ( Dad )

I think a 134 retrofit kit is like $8 at Autozone. It comes with the high and low side fittings and the longer schrader valve tool (~ half inch instead of the quarter inch long?).

I can't see the need for a whole new hose unless the threads on one or more of the parts are stripped: 134 valve onto the R-12 port, new schrader into the 134 valve.

If the 134 conversion were done 'correctly' and the old fitting is trashed, then you might need a new hose. There's supposed to be loctite on the 134 fitting, but mine just unscrewed with a wrench.

Since it's empty, do yourself a favor and find one of the high quality brass adapter fittings. When removing your current adapter, remove the original Shraeder valve before installing the brass adapter. These cost $6 or $8 but well worth the extra cost.

I buy them locally at an auto supply that caters to the repair shop trade, but if you can't find them locally, check with some of the internet suppliers such as acsource or ackits. Add a dot com to those names.

Thanks. I may not have described this correctly though. I believe the conversion to 134 was done using a both new hoses not adapters since both have a quick disconnect fitting and not a screw on type.
??

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92 500E Silver 66k
82 Porsche 911SC 84K
68 Cadillac ( Gone Now )
03 Suburban Z71 200K
85 300SD 217k From Original Owner ( Dad )

It would be very unusual to find new hoses with 134a fittings on an old car.

Picture?

Yak , I will take it in the a.m. and post it.
Thanks
Alan

__________________
92 500E Silver 66k
82 Porsche 911SC 84K
68 Cadillac ( Gone Now )
03 Suburban Z71 200K
85 300SD 217k From Original Owner ( Dad )