finding AC leak

[dave silva]

I'm a self taught HVAC hack.

THe AC had just a pit of pressure after a few years sitting. I vacuumed it down and it began to lose vacuum after a couple hours.

I do not have nitrogen but i do have a case of Duracool and compressed air so i can soap bubble the fittings with either of those (sacrificing a can
of duracool)

Any tip on techniques or the most likely place to find a leak?

Should i just get a bunch of O-rings or is there GMC specific collection?

thanks

--
Dave & Ellen Silva

1972 Revcon Olds 455, toro drive train. All Stock

 

[emerystora]

I just did this with mine. I didn’t have nitrogen so I bled the water off my air compressor and charged my system to 20psi. I found one slow leak but it was where the low pressure hose was attached. I tightened that with pliers and no more leak. I then vacuumed it overnight to get all the air and water out.

Emery Stora

>
> I'm a self taught HVAC hack.
>
> THe AC had just a pit of pressure after a few years sitting. I vacuumed it down and it began to lose vacuum after a couple hours.
>
> I do not have nitrogen but i do have a case of Duracool and compressed air so i can soap bubble the fittings with either of those (sacrificing a can
> of duracool)
>
>
> Any tip on techniques or the most likely place to find a leak?
>
> Should i just get a bunch of O-rings or is there GMC specific collection?
>
> thanks
>
>
> --
> Dave & Ellen Silva
>
> 1972 Revcon Olds 455, toro drive train. All Stock
>
>
>
> _______________________________________________
> GMCnet mailing list
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> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[terry1]

After you pressurize it with whatever you chose, be sure and rotate the crankshaft by hand several turns to lubricate the shaft seal. It may be the
leak you won't be able to soap bubble, especially if the unit has been idle for an extended period. Those leaks will stop after some operation, but
you will lose some charge until the seal is lubed from within. Dye and operation always seemed the best detection method, I always look for the oil
first to locate leaks unless I can smell refrigerant/oil vapor coming out of the vents.
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[Matt Colie]

Dave,

Using Duracool was a good answer, but if you have a can of propane around (like for the grill or a portable heater) just get a POL and the fitting to
make it to 1/2 Acme for the new auto A/C and use that. It HAS TO BE dry and you really don't need to get it all out before you recharge. You do want
to if you can because the odor in Propane is ethyl mercaptan and it does have sulfur in it that will do you no good and can be bad if the system gets
open to moisture.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

 

[dave silva]

Yay- turns out i do not have a leak- operator error.

I checked my vac gauge after a couple hours it it had moved noticeably.

So i left it.

Went back 24 hours later and it was still in the same place, tightened the valve on the gauge, opened hte valve on the AC fitting and the vac went
back to 30.

So the coach is holding.

life is good.

--
Dave & Ellen Silva

1972 Revcon Olds 455, toro drive train. All Stock