Pressure switch issue?

[aribert]

JohnHere:
"...are you sure that your testing apparatus (Manifold Gauge Set, hoses, etc.) aren't leaking someplace? "
I don't think so, I have experienced a leak in the past. Since the results from both gage sets were within 1 psi I find it doubtful that both gages/hoses had a similar leak (rate).

No luck in finding the filter/dryer P/N to see if it has the Schrader valve under the pressure switch. I have a message in to Tim for parts. I'll loosen the pressure switch and if it appears not have a Scharader valve, I'll need to poke around if anyone near me still does R12 recovery. My late father had a late 80s or 90s vintage refrigerant recovery unit but it was flooded in Harvey and while I did power it up after it had dried out, I was way too busy saving the house to mess with it (its still sitting in the garage down there but I am in MI). If not, I will try to draw a vacuum on my empty R12 tank and then connect the tank to the system to try to recover some of the R12 - I still have 15+ lbs to play with in the other tank.

[Tim]

Look back at a post or two. I posted a drier last night.

[aribert]

Thanks for contacting us. I'm going to need an image of the TXV valve. It could be a standard universal. But an old under-dash system like that might have something different.

R12 is harder to find these days. I may be able to find a cheaper Drier. Is this the type of drier you are looking for?

37-13732-AM

Yes - that is the style of dryer I need. I like that it has a service port. My existing dryer has a port for the pressure switch on it. If pressure switch port is not available on the dryer, is there an inline fitting I can place immediately after the dryer to mount the switch (fitting length would be limited to 2 inches)?

Expansion valve image attached. Looks to me to be same/similar to 4 Seasons P/N38608.

expansion valve.JPG (47.18 KiB) Viewed 3179 times

[Tim]

As long as it is an O-ring valve.

31-10912-AM

[aribert]

As long as it is an O-ring valve. I have no idea if the valve connections are flare or o-ring. I think I may have a spare evaporator core squirreled away in my spares but will not get to access that for several days. If I have a spare evaporator, it would tell me the connection configuration.

Link for the 31-10912-AM is not working for me.

[JohnHere]

Link for the 31-10912-AM is not working for me.

It doesn't work for me, either.

The R/D that Tim linked to has a Schrader valve in the Binary Switch port. You won't need a separate in-line fitting.

[Tim]

Fixed.

[aribert]

Tim:
The expansion valve has flair fittings.

Would 37-13309-AM be acceptable for use w/ an R12 system? The R/D appears to have been used on mid 80s Porsche (and some late '70s to late 80s Freightliner and Mack if the internet is correct). Does this R/D have a sight glass? What threads on the switch port?

I'd like to end up with two R12 service ports on the dryer - one for service and one for mounting the binary switch. Do you have an R12 Binary switch with 7/16-20 female threads and with the pin that would contact the Schrader valve?

Do you have an R12 service port fitting? Ideally one that would thread into the R/D switch port (if not still interested in the fitting, esp if brass or steel - I could always machine the bottom half of the fitting to mate with the R/D switch port and silver solder to make a custom fitting)

[Tim]

Best we can do.

17-2603


43-MT1482

[JohnHere]

Do you have an R12 service port fitting? Ideally one that would thread into the R/D switch port (if not still interested in the fitting, esp if brass or steel - I could always machine the bottom half of the fitting to mate with the R/D switch port and silver solder to make a custom fitting)

How about something like this:
https://www.centurytool.net/3_Pack_T_Co ... savt2p.htm