It sounds like the A/C system has been converted to R134a. The old R12 systems use schrader valve service ports which are replaced with a new style port during the conversion. I attached a picture of the new R134a service port.
(Very) basic A/C question
Aren't the high/low ports on the compressor supposed to have "shrader type" valves in them?
I took the caps off and just see holes - no valves.
I would imagine they are screw in? They appear to be missing on my car. I just bought it last year - trying to charge the system.
I took the caps off and just see holes - no valves.
I would imagine they are screw in? They appear to be missing on my car. I just bought it last year - trying to charge the system.
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It definitely doesn't have an adapter like that. Just an aluminum-looking cap on the original service port.
Are the R12 shrader valves removed when the 134 service ports are installed?
If so, maybe the system was converted, and he took them off to sell the car, and just placed the original caps back on the R12 ports.
Either way, I need to get the valve cores.
Are the R12 shrader valves removed when the 134 service ports are installed?
If so, maybe the system was converted, and he took them off to sell the car, and just placed the original caps back on the R12 ports.
Either way, I need to get the valve cores.
The R12 schrader valves are not removed, r134a ports are screwed onto them and act as an adapter rather than a replacement.It definitely doesn't have an adapter like that. Just an aluminum-looking cap on the original service port.
Are the R12 shrader valves removed when the 134 service ports are installed?
If so, maybe the system was converted, and he took them off to sell the car, and just placed the original caps back on the R12 ports.
Either way, I need to get the valve cores.
Exactly what vehicle are we dealing with and what kind of compressor? Many of the older systems used York or Techumseh compressors with actual service valves that are opened for system servicing, not just service ports to attach the hoses from the gauge set. These service valves did not have schrader valves in the hose ports.
Just a thought...
Just a thought...
yes the valves srcew in with the same type of tool used on the tire stems. you can buy new valve cores at any hvac company.
Looking at the pic, this is either a York or Techumseh compressor. You have service valves that do not use the shrader valve. These valves on your system offer more troubleshooting ability for the technician, but they tend to leak over time. If you're not experienced using these valves, I'd definately take it to a shop.
Hybrid - that's the first I've heard of a system NOT having a shrader valve. How do you get the system to take freon since the connected hose has nothing to depress to get the refrigerant in?You have service valves that do not use the shrader valve.
You have to manually open and close the valve, There's two caps, one kind of looks like the schrader valve cap, then another long cap that covers a shaft, usually square on the end, that you turn to open and close the valve. If one or both of yours are leaking, replacements are readily available.
Joel
Joel
Its all described in the shop manual. The service ports are kinda nice in that you can remove the compressor from the system without having to discharge the system. You just close the valves and take them off the compressor and only the compressor gets discharged. Schrader valves were a later, cheaper way to hook up to the system.
Thanks Joel - I guess that's what that other large cap is that's pointing forward just around the corner from the shrader type cap.You have to manually open and close the valve, There's two caps, one kind of looks like the schrader valve cap, then another long cap that covers a shaft, usually square on the end, that you turn to open and close the valve. If one or both of yours are leaking, replacements are readily available.
Joel
I had also taken that cap off and seen the shaft in there - but was baffled about it's usage. Now it makes sense.
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