A/c diagnosis help

[greatmizzou]

So last summer my a/c went kaput.  I recharged it and it was ice cold like it used to be.   I noticed when I tried to recharge it a little rubber ball went flying out of the Schrader valve and I have no clue where it went.  I’m assuming the valve was leaking and that’s why it did that.

 

i haven’t had time to address it since winter hit but I want to get this fixed before summer hits.   I noticed now the a/c is bone dry and the compressor won’t stay on.  I just tried to recharge it and it’s definitely still leaking real bad at the valve.

 

Other then replacing the Schrader valve, or maybe tightening it, what else do I need to do? 

 

Should I service all of the valves?

 

02 Silverado ext cab 170kmi.  5.3 v8  4x4

[sefiroxx]

Little ball is likely from the gauge set where it connects to the shrader valve.

Leak could be coming from anywhere. You will need a leak detector to find it, and that will require the system to be under pressure (filled).

And if the system is bone dry, moisture is probably in the system. You will need a vacuum pump to remove the moisture

[carnau]

On 4/1/2019 at 7:17 PM, greatmizzou said:

So last summer my a/c went kaput.  I recharged it and it was ice cold like it used to be.   I noticed when I tried to recharge it a little rubber ball went flying out of the Schrader valve and I have no clue where it went.  I’m assuming the valve was leaking and that’s why it did that.

 

i haven’t had time to address it since winter hit but I want to get this fixed before summer hits.   I noticed now the a/c is bone dry and the compressor won’t stay on.  I just tried to recharge it and it’s definitely still leaking real bad at the valve.

 

Other then replacing the Schrader valve, or maybe tightening it, what else do I need to do? 

 

Should I service all of the valves?

 

02 Silverado ext cab 170kmi.  5.3 v8  4x4

Yeah, the valves tend to leak, and the little rubber ball thing you're talking about is probably the seal in the high pressure fitting (see picture below). I replace these fittings a lot. You can remove the high pressure fitting with a socket, but I always recommend using the proper tool to do it. Hope this helps, Here is what you need below.

 

Here is the fitting you need.

High side - https://amzn.to/2OEg5ul

Low side - https://amzn.to/2K4tWLI

High side socket - https://amzn.to/2VgkO7I

Low side tool - https://amzn.to/2VddxFW 

 

 

[greatmizzou]

Any thoughts on a vacuum to DIY the ac ?

[sefiroxx]

You'll need a vacuum pump and a full set of guages. Some of the parts houses have them on a tool loaner.

After repairs,
- connect vacuum pump to the yellow house and hookup both high and low.
- Close high valve on the guage manifold, open low side
- run pump until pressure drops to -25 to 27.
- close low side, disconnect pump
- change oil in the pump (first round of vacuum pulls moisture, oil and particulates which limits the pump from achieving highest vacuum)
- reconnect pump, start pump, wait 15-30 seconds and open low side slowly.
- wait until pump achieves -29.5 to 30.
- stop pump, close pump valve, close low side.
- monitor vacuum for a few hours, overnight is best.
- if vacuum holds, proceed otherwise repair
- connect Freon tank to yellow hose, bleed air from yellow hose thru shrader on manifold until Freon flows
- open low side to allow Freon to replace vacuum
- initial load of Freon this way will usually achieve enough static internal pressure to satisfy the low pressure switch allowing the compressor to run
- with compressor running, add Freon per specification
- disconnect guages per instructions (usually, with compressor on, turn off Freon can but leave connected, close high side at the connection near engine, open high side at manifold so excess Freon can be pulled into system, closer low side at engine, disconnect low side, stop compressor, let sit for a couple of minutes, disconnect high side, disconnect Freon can)

[greatmizzou]

Thanks for the help everyone after replacing the valve stem’s and getting the lines vacuum sealed AC is working now just as normal :-)

[greatmizzou]

On 4/2/2019 at 6:48 PM, carnau said:

Yeah, the valves tend to leak, and the little rubber ball thing you're talking about is probably the seal in the high pressure fitting (see picture below). I replace these fittings a lot. You can remove the high pressure fitting with a socket, but I always recommend using the proper tool to do it. Hope this helps, Here is what you need below.

 

Here is the fitting you need.

High side - https://amzn.to/2OEg5ul

Low side - https://amzn.to/2K4tWLI

High side socket - https://amzn.to/2VgkO7I

Low side tool - https://amzn.to/2VddxFW 

 

 

Thank you!!  So far several days of driving in hot weather and AC still ice cold.  I hope it gets me through to winter.

 

my system was empty of Freon with no pressure and took two cans of refrigerant.   Pressure seemed good and I should be right in the operable total suggested weight of r134.  None of the valves are leaking.  

 

 I’m glad I used safety gear because when I disconnected the high and low pressure sides and went to release the manifold pressure so I could return it, some Freon was still in the little manifold hoses and would have cold burned my hand.  I hate having any of it discharge even just a little bit but I imagine the stuff left over in the manifold hoses is unavoidable?  I was surprised how much was in a foot or so of hose.

 

 

 

 

Edited June 3, 2019 by greatmizzou

[sefiroxx]

Newer/better guages have shutoffs located at the end of the hoses that allow locking in the Freon into the hose and limit the amount that escapes on the disconnect.

Also, to minimize storage pressure and to minimize chance of blowing the seals inside the guage quick connect, do the following:
- engine running, ac on
- shut off high side
- open both hi/low at the dial to allow drain of t
Hi line
- shut both hi/low at the dials
- close low at the end near valve
- turn off ac, let system equalize
- disconnect hi