Want to be

I found the leak on my AC, its the schrader valve. Does anyone know the actual connection size of the low and high inlets and what size schrader valve do i need? My connection port is leaking so much i had to use a wrench to remove the cap and then the freon started rushing OUT. i put the cap on for now but i need to replace it.

Any help would be appreciated. thanks

Ed Scherer

I believe that R-12 Schrader valve cores are standard sized ("1/4 inch"). A good A/C or auto parts place (e.g., NAPA) should have them. Example: .

Also note that there are tools that allow you to change an R-12 valve core without losing your refrigerant charge (although if yours is leaking a lot, you'll lose some when you have the cap off). Example: .


This is assuming you're still running R-12 and your system hasn't been converted to use R-134a.

CraigL

If you are tired of burning your hands when dealing with the low pressure valve with a hot engine, you can use this opportunity to install an extension tube ... relocating the Schrader valve to a point 6" higher than it is right now.

928mac

Do you have a picture Craig, that sounds really cool.
No pun intended.

Want to be

Yes i am interested in the extension tube. I would assume the extension tube would fix my problem and elminate the need for the tooling. Please direct 928mac and i to the extension tube.

Regards to the tooling, i guess my lowside is a 1/4 inch connection. The Master cool model listed states its for a 1/4 inch connection. This tool seems better than the tool i was looking at on ebay. I was also looking at a tool at and autopart store for 110 dollars.

M. Requin

^+1

CraigL

This modification is a no brainer. You will need a few inexpensive parts. Here are a few links to give you an idea about what we used:

http://www.grainger.com/Grainger/14-In-Extension-Tube-4PDH2?Pid=search

The one we used had a longer extension tube ... about 6". We bought the fitting and the tube. Then silver soldered the two together.

http://www.grainger.com/Grainger/PARKER-Short-Nut-2P151?Pid=search

This nut is used to attach the assembly to the existing low side port.


Here are the "instructions":
1. Remove Schrader valve from the low side port.
2. Assemble the extension tube and the female flare nut.
3. Flare the tube
4. Screw the extension onto the low side port
5. Check for leaks

The whole thing cost less than $20 and took 30 minutes to find and assemble. Two years ago I wrestled with charging the A/C. My hands are large and I burned them while getting the hose on/off the low side Schrader Valve. Someone (Bill Ball?) recommended asbestos gloves. Ha! Now the valve is right next to the jump post and there is no possibility for thermal injury.

Here's a few additional photos. The last one is a shot from underneath, looking up.

dr bob

Copper tubing extension like that is a ticking time bomb. Normal vibrations will eventually cause it to fail, plus you are ading at least one more possible leak location on purpose.

How often do you guys need to access that low-side connection?

To the OP: Get a new Schraeder valve core from a good parts place. Size and shape are same as a tire valve, but the seals for the AC oil are different. IIRC, the last bunch I bought had light green seals on them.

That said, it might be worthwhile taking the car to a good AC shop and let them change the core using a tool they own that won't spill much refrigerant. Takes them minutes, vs you chasing down the right tool, and fumbling with it in the driveway. Probably costs less net that doing it yourself.

CraigL

>
> Copper tubing extension like that is a ticking time bomb.
>
Drama!

>
> Normal vibrations will eventually cause it to fail,
> plus you are ading at least one more possible leak location on purpose.
>
Maybe. Better than having burned hands.
This solution is working well for me. So far.

dr bob

Experience!


Better solution is to fix the leaks, then attach the hoses while the engine is cold. Fill the system cold, by weight, and remove the hoses. Engine is still cold. This is the solution that worked well for me. So far. I think the last time I attached a hose there was late in the last century.

Want to be

Just curious if anyone has used the 91490 tool? I just got mine today and it appears the connection is 1/2 inch. I don't see how i can get a good connection with a 1/2 inch on a R12 connection. Maybe its a pack error...Anyone have one that could measure it the OD on the blue connection piece?

Want to be

i stopped the leak with a 90 degree elbow. It has a depressor and a scharder valve.

Cheap way to repair without the need to bleed down your system. I am now testing to see if i lose any freon. I am monitoring it with a ac pressure gauge.

The tool i purchased was worthless for R12 but will work on r134a. The kit says r12 but only comes with r134 low and high side connections. The mastercool tech told me to remove the 134a connection and just screw it on the r12 connection. I lost alot of freon messing with it and later found out myself the threading is different. I am going to call the tech again and see if they actual sale the correct connections to help others down the road..

Ed Scherer

Something is really weird about that... mine has been used a couple of times on R-12 systems (mine and once on someone else's car).

Does it look like this one on eBay?



I'll try to remember to look at mine again this evening when I'm at home.

Want to be

Yes and No
Your pic end piece connection looks like a r12 connection but mine is like a r134a

Must have been a pack error the box states it's a r12 device

WallyP

You need a good cap on that angle connection.