A/C - Changing the Schrader valves -- what size are they?

Hello everyone,

Well, I was quite pleasantly surprised to find out that my A/C system is working wonderfully today. I got this car knowing the A/C system had had a leak but it wasn't until this weekend that I was able to pull a vacuum and refill it with the correct amount of r134a and everything is purring like a kitten.

As a bonus, I think the leak seems to be originating from both of the schrader valves. When I put the sniffer to them they perked up, but it's a very slow leak thankfully which gives me a little more time to fix them.

Question: I've searched Priuschat and strangely nobody has asked this question......What sized schrader valves does the A/C system use for Gen 2 Prii? I've looked high and low even in the A/C systems manual from Toyota that was downloaded online and I cannot find any reference to sizes of valves.

I'm under the impression that the valve size is JRA at least for the high pressure side (a larger than standard sized valve I think) and I don't know if the low side is also considered JRA or standard. Honestly, there's not much information on the net about any of this, so if we could have any A/C wizards weigh in it would greatly contribute to the Priuschat forums I think.

There's a really cool tool for changing out the schrader valves without having to purge the A/C system by Mastercool (5831) which I want to buy and change out the valves myself then sell the part afterwards. I think this is the right sized tool again, but I'm just going on what people generally say about Japanese cars (imports). I've also contacted the dealership but no return call today. I'll post more information if I get it on here. I'm so happy to have A/C again, it's 94 degrees down in town in Kailua-Kona, Hawaii and we're the hottest of the islands pretty much all the time! It felt so AMAZING to finally have a Prius with A/C. I was thinking I'd never get around to fixing it.

 

Just an update, I believe the valve cores are JRA (Japanese Refrigerant Association) sized valve cores so I went ahead and bought the tools on Amazon to swap out the two cores. Hopefully this will stop my sniffer from detecting leaks around the schrader valves.

 

Hello everyone, I wanted to give you all an update on my A/C leak. I received my Mastercool Valve Core Remover/Installer r134a Kit Standard and JRA size and it took me about 30 minutes to change out my High and Low pressure Schrader valves.

My A/C sniffer was definitely telling me that refrigerant WAS leaking around these valves at a slow rate. After changing out the valves, I soapy water cleaned out the ports after they were changed to remove any traces of refrigerant then dried them out. After they dried I put the sniffer to them and there was no detected A/C leaks! The other kit I purchased had replacement JRA (large sized) core valves and new caps.

I purchased the car and there was no Low Pressure cap installed on the low end, which is a big NO NO. The caps themselves have o-rings to keep extra pressure on the system, so I am very pleased that my A/C system seems to be nice and tight and working like a dream. I will post some photos here of the repair in case it may help someone who finds they have leaky Schrader valves and does not want to lose all of their refrigerant.

I'm pretty amazed at how easy this was to do. What's funny is the local shop guys didn't even know such a tool existed! They asked me how it worked and I explained how you can change out the valve without having to evacuate all the refrigerant. I feel so smart (which will wear off in a day or two).



A demonstration of this tool can be found at the company website.
Mastercool Inc., Manufacturer of Air Conditioning, Refrigeration, Service Tools and Equipment

I purchased my replace caps and core valves with this kit:

Four Seasons 26783 Cap & Valve Air Conditioning System Seal Kit

I hope this helps some of you out there!

 

Not quite a happy ending....while driving down the road A/C has been getting warmer past few days. To my dismay, I shut down the A/C system to prevent damage to the A/C compressor. It appears that my new Schrader valves are still leaking! Apparently they are temperamental and need to be seated "just right" otherwise they will never stop all the pressures. I used dye light and could only find residue near the caps. The high pressure side cap definitely let out some pressure, like opening a can of soda. It's really annoying because now I have to evacuate the system AGAIN and refill the system. A word of warning to those out there, make sure you keep checking your new Schrader valve cores daily after refilling your system. Check for dye, check for leaks (sniffer) check for cap pressure, check it all and from what I can tell, the fix is to make sure the valve core is installed well and to use needle nose pliers and push briefly on the center of the valve and gently pull back to reseat the valve core. I will be doing this this weekend most likely.

Note: Brand new caps with new washers were used as well, so the caps did their best but cannot hold back crazy 100 psi pressures. Below are photos from High Side (Left) and Low Side (Right). I had done my best to clean the valves so the yellow tint is all from escaping refrigerant.

 

Update, I cleaned the valves with alcohol and gave the valves a shot each with a q-tip. They blasted all the alcohol off and look all clean again. I just filled the system again with r134a. I'm really glad I didn't hurt the compressor. No leaks detected (yet). Will monitor very closely to see if the Schrader valves start acting up again.

In hind sight, I had noticed my leak detector was going off just a little bit every so often if I put it in the valves. I was thinking it was just residue from the fill up but now that I think about it, it was registering tiny amount of gas leaking out. I checked again tonight and it is quiet, and hopefully will stay quiet for the foreseeable future.

 

Perhaps, but because the size is a universal part, they should be available with any A/C repair place.

It appears that my A/C sniffer was still going off around the ports which makes me think that these Schrader valves are temperamental to say the least. Maybe I'll just have to buy more new ones and keep trying until something just works.

And now, it looks like my cheap $20 A/C sniffer from amazon isn't working....*groan*