I replaced my ac low side valve core with this part # MT0064-4 from autozone. It leaks. Is there somewhere I can get the right replacement? I went to napa and the man went through a drawer full of them and came up with this one. It leaks too. I am sick of working on this a/c system. Have you ever heard of a piercing tool not working. I have one, can tap is not letting fluid out. I have a side can tap on the way, should be here tomorrow. Damdest thing I have ever seen!

Edited October 1, 20186 yr by slowpokedodge

Did you load the system with green dye and check with a UV light if the dye was leaking back out? Might have to blast out the nipple with a bit of brake clean to start clean and to check if the dye is leaking back through.

 

Isn't there a special adapter you have to use with that fitting, or you can damage it, what I heard 

The valve is leaking bad, blowing back out, The truck took about 3/4 of a can of freon. The compressor would cycle off and on but never got cool. Would not take any more freon. The tool is nothing special just a regular valve core tool. I put green dye in it again, never found the first leak. Thought it was the evaperator core because of the loud hissing from the hvac. Guess I will try another place tomorrow for the valve core. It is bad and need to be replaced. You should see what the parts place tried to sell me for the heater core hoses. It was l shaped and about 4" long on each side.

How are you putting the freon in? Using gauges or just putting it in with a hose? If the compressor is cycling on and off it most likely wont get cold until it stays locked. 

9 hours ago, slowpokedodge said:

The truck took about 3/4 of a can of freon. The compressor would cycle off and on but never got cool.

 

It takes 3 cans of freon to make them cool. What is happening is the can is freezing up and quits producing gas. This is where I get a 1 gallon ice cream pail and fill with hot water and place the freon can in the water. The pressure will rise sharply in the can so it's best to have a manifold gauge set. 

I usually prop my can up near the oil filter at the exhaust manifold. The air of the fan and the heat off the manifold works pretty good also.

Just make sure to never let the can flip upside down. This will dump liquid freon on the suction side of the compressor which can possibly cause a hydro-lockup of the compressor. Can be rather explosive. 

 

 

 

18 hours ago, dripley said:

How are you putting the freon in? Using gauges or just putting it in with a hose? If the compressor is cycling on and off it most likely wont get cold until it stays locked. 

I am using gauges. Thanks.

9 hours ago, Mopar1973Man said:

 

It takes 3 cans of freon to make them cool. What is happening is the can is freezing up and quits producing gas. This is where I get a 1 gallon ice cream pail and fill with hot water and place the freon can in the water. The pressure will rise sharply in the can so it's best to have a manifold gauge set. 

You told me this 3 years ago, u'd think I could remember things. I do have a manifold set, harbor freight but it works. Any way, the valve core is leaking and napa will have me one tomorrow. So I guess its good that it was freezing up or I would be doing it over again. I have seen people turn the cans upside down but I haven't. Thanks for the tip.

Well the deed is done. Replaced the bad a/c valve stem after work. Pulled a vacuum for 30 minutes and let it set for another 30. Nothing moved on my ac gauge. The truck would only take 2 cans of freon. Put the can in hot water. 2 cans and I tried to put a can of 100pg in but not much went in. Put a thermometer in the vent and it got to 51 on low and 56 on high. Not as cold as the last time 3 years ago. It did not take the correct amount of freon so may not be fixed. Hope it blows cold in the morning. Thanks for all your help and I wonder why it only took 2 cans?