Automotive Air Conditioning Information Forum (Archives)

Jenkser on Sun October 19, 2014 2:43 PM

Year: 1995
Make: Chevy
Model: Caprice
Engine Size: 350
Refrigerant Type: R134a
Ambient Temp: 95
Country of Origin: United States

Recently, I ran into a problem with the Low Side Service Coupler on my AC Gauges. The valve would not open to allow a vacume or charging of the system. Looking at the Coupler, it appears to function, but after turning the knob to open it, no air (or refrigerant) will pass through it. To test the Coupler I hooked it up to my vacume pump, or you could just blow into 1 end like a whistle. The problem is I have gotten 3 replacement Couplers from 2 different manufactures and they all have the same problem. I called the manufacturer (Robinair) and was told that there must be a bad batch. When I checked the reviews for the gauge set I found others with the same problem (Low Side Service Coupler) One guy even said he replaced his compressor and it turned out to be the L.S.C. I was told that all the couplers are from 1 manufacturer and you are just paying for the name if you pay more, by Tech support at Robinair (not sure how true that is, but it's what he said). So if you are having a problem with your system not taking a charge, don't instantly blame it on a restriction or bad compressor, test the couplers (even with a new set of gauges) and you might save yourself some time and money.

Edited: Sun October 19, 2014 at 7:22 PM by Jenkser

wptski on Sun October 19, 2014 9:47 PM

Isn't the valve core depressor pin moving when you turn it in or to to the open position? I have CPS brand adapters used with 1/4" flare hoses and you have to get the feel when than valve core is really open.

Edited: Mon October 20, 2014 at 10:55 AM by wptski

TRB on Sun October 19, 2014 10:18 PM

Robinair telling someone you are just paying for the name is funny as hell. Get a professional coupler like the type Mastercool or Santech sell.

http://www.ackits.com/mastercool-service-tools-and-equipment/service-port-couplers-r134a-professional-mastercool


-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

mk378 on Mon October 20, 2014 12:04 AM

Some of them have to be actually coupled AND the knob turned before the valve will open. Test by coupling to a conversion fitting that isn't attached to anything.

Jag987 on Mon October 20, 2014 1:54 AM

TRB, so are you saying when someone buys robin air, they are not just paying for a name? I think Robinaur has a name, and that name is "overpriced"!!!

ditto on what MK said, some couples have to be hooked up to a service port to work, even if they have a knob to turn that depresses the shearer valve.

-------------------------
I bought a can of 134a at w**-mart that had a stop leak, oil, and dye in it. It also had a hose and a gauge, so now I'm an AC pro!

wptski on Mon October 20, 2014 9:04 AM

Like many other things these days, who actually makes their own products?? There is a Yellow Jacket P/T calculator that has a circuit board inside stamped Mastercool whom has their own similar device with more features and cheaper.

The OP has stated that they are turning the knob to open the valve. I tested mine when new like mk378 mentioned and marked them with a Sharpie pen.

Jenkser on Mon October 20, 2014 9:33 AM

Thanks for the responses guys! I called Robinair's tech support again and this time I was told as mk378 said that it has to be hooked up because there is a check valve inside. I could only go by how the high side coupler worked (and low side that originally didn't) and what the first Robinair tech told me, and that is why I posted this thread. Again Thanks for everyone's help.

wptski on Mon October 20, 2014 9:39 AM

Quote
Originally posted by: Jenkser
Thanks for the responses guys! I called Robinair's tech support again and this time I was told as mk378 said that it has to be hooked up because there is a check valve inside. I could only go by how the high side coupler worked (and low side that originally didn't) and what the first Robinair tech told me, and that is why I posted this thread. Again Thanks for everyone's help.
I doubt if there is a so-called "check valve" because that restricts flow in one direction but one needs flow in both directions for A/C work. There'd have to be a valve seat type inside if that's the case.



Edited: Mon October 20, 2014 at 9:42 AM by wptski

TRB on Mon October 20, 2014 9:44 AM

Robinair is lie Snap-on to me. Good stuff but over priced compared to other options.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

Jenkser on Mon October 20, 2014 10:55 AM

Robinair tech support (second time) said it was like a check valve, he was talking to someone else in the background and he was not understanding my question or exactly how the coupler works but in the end he was able to explain it enough that I was able to understand how it works. (with everyone's help here!)
There is a valve seat in the coupler. If you look inside you can see a little pin that goes through the bottom part of the pin that comes out when you turn the knob CW. To test the coupler I took a piece of 3/8" of pipe and pushed down inside the coupler, then I blew on the other end and air came out of the other end (of the pipe). This at least lets me know that the valve does open and doesn't stay closed like the one that I am replacing.

Edited: Mon October 20, 2014 at 11:18 AM by Jenkser