Fixing R12 A/C + Oil pan question
 

Hi guys,

I am helping my brother fix his 92 Cherokee 4.6 stroker (our dad built it for him for the most part pretty cool build...anyway...) with his A/C and a few other minor things.
I have access to R12, vac pump, gauges etc... and have done a ton of work on my Mercedes A/C systems both R12 and R134a but never dealt with a Jeep before.
Two A/C questions:

1) There are no schrader valves at all and I bought a kit from Napa and they don't fit. What's the deal? Is there something different about Jeep's service ports or something?
2) SINCE the car has been open to the air for years, we have a new drier. What is the quantity of mineral oil to put in it?

Oil pan question:

What is the torque setting for oil pan bolts? He told me he ripped the gasket and its leaking everywhere and I believe he is doing it too tight. He said he keeps breaking the bolts that is why unless they are a weak point??

The R12 system has high and low side ports located on top of the passenger side of the engine compartment (same location as R134a actually).

The torque specs for the oil pan bolts are:

1/4" bolts = 10 ft lbs
5/16" bolts = 13 ft lbs

Those bolts shouldn't break unless they are being overtorqued.

If the oil pan bolts were tightened to the point of snapping, the pan lip is probably deformed around the bolt heads now and the gasket will never seal. You may be able to level it out again with careful application of a hammer...

Right that is what I thought too. Thanks.
(only thing is are you sure ft lbs not inch lbs?)

I know where the ports are, I just don't understand why there are no schrader valves installed?

Yes ft/lbs.

R12 systems don't have quick connect/disconnects like R134a. The connectors you are looking for should be threaded.

Should there be schrader valves installed and if so, why won't the valves that I have work that is what I asking.
I have R12 on my Mercedes I am familiar to what everything looks like and the location of the service ports and all other components.

The low pressure service valve on my '92 XJ is located on the REAR of the compressor. You need to use the R/12 threaded lines and open the service port on the compressor by turning the little 7mm shaft on the valve body on the compressor. Remove the black "caps" and you will see the valve shaft that needs to be turned.

They open by turning clockwise and open them no more than about one to two turns -- just enough for refrigerant flow.

So are you saying there is no schrader valves at all on the cherokee's? This 7mm shaft acts in place of it?