Do you need an adapter for the hi pressure side to use an AC manifold gauge set? All my hoses on my set are flares and the hi fitting is different than the lo one.

 

Yes; the high side is a smaller size, to prevent someone without sufficient knowledge from accidentally hooking a can to it, such as with one of those DIY charging hoses.

 

Does the hi side fitting not have a schrader valve inside?

 

Yes indeed it does.

 

I am trying to get the AC working . I need to get my gauge set on system to help determine what is wrong. I have noticed fluid on perimeter of clutch and under compressor. I bet a seal went. The compressor cycles and the lo side works as it should, 20 psi on & 45 psi off . Just need to get on the hi side with gauges. Since I need an adapter, what and where?

 

Yup, that'll be the compressor seal.

It's "possible" to simply replace the seal, but after however many years & miles, ...

Better to just replace the compressor, accumulator, ALL O-rings, and ALL rubber line sections; flush ALL remaining metal parts (comp, evap, & metal line sections) w NON-RESIDUE solvent such as acetone, lacquer thinner, denatured alcohol, or (gasp!) A/C flush; replace the orifice tube w the Frod red/orange one for about a 96 Crown Vic; pour about 2 oz of about "75" PAG oil (the "medium" kind; not 50, not 100, somewhere in between) into the suction port of the new com, and about 3 oz into the new accumulator; pull a deep vacuum on it and make sure it goes below 29", then stays below 28" for a half-hour after you disconnect the pump; then charge it w R-134A.

Of course, before doing this, make DOUBLE DAMN SURE your cooling system is working PERFECT, especially the fan. After all, if you thimk CORRECTLY about how the A/C works, you'll realize that it's not a "cold generator"; rather, it's a CONVEYOR SYSTEM FOR HEAT. It takes heat from the cabin, moves it into the refrigerant at the evaporator, moves the heated refrigerant to the condenser, and GIVES UP THE HEAT FROM THE CONDENSER TO THE OUTSIDE ENVIRONMENT. It cannot do that if air is not moving through the condenser at all times, and then has enough heat absorbing capacity left over to also cool the engine, meaning, the fan HAS TO BE working right.

You don't generally need to worry too much about the high side pressure. If the low side does what it should and the system cools and there's plenty of air flowing through the condenser, the high side pretty much takes care of itself.

 

thank you for your help and info