TaylorLG

I purchased a A/C replacement kit with compressor, dryer and expansion valve. it has no directions and I have questions.

How much oil to install? it says check the label under the hood but I can't find a label concerning the compressor oil capacity.

How to remove the expansion valve from fire wall? do I have to remove dash and HVAC box? I see the nuts behind the expansion valve, do i just loosen those?

I would appreciate any help or link to instructions.

Thanks!

cruiser54

Why are you replacing the expansion valve?

It is removed from the engine bay.

Bryan98XJ

Are you converting this system over to r134a?

ajpulley

The expansion valve is removed by loosening the flare nuts that enter the rear of it, top and bottom.

The total system charge for R-134 would be in the factory service manual (same as for R-22, if applicable). For '87, it's 5.7oz of oil, and 36oz of refrigerant, if you are replacing everything. The following valves can be used if you need to replace the old ones on a Sanden- they don't have front/back seat valves, just quick-connects w/ schraders:

Four Seasons 14720
Four Seasons 14718

To correctly convert to the newer refrigerant, you should be replacing your hoses, chemically flush your evaporator and dry with nitrogen, and replace all your o-rings with HNBR-type. It is best to replace the original serpentine condenser with a new parallel type. Once the system is put together, pressure test with nitrogen, evacuate, break with nitrogen, evacuate again, break a second time, evacuate a third time, then charge.

If you can't measure the refrigerant, then it gets more complicated to do it correctly.

MonacaYankee

1987 will have an r12 system. Are you charging it with r12 again? If not you have a ton of work to do r-134 the right way.

Compressor should have came with oil in it. Find that out then add a couple ounces in your line for the condenser.

The expansion valve was a pain to remove on my 94 but your 87 will have a overflow tank right next to it instead of a wiper fluid bottle.

On my 94 I had to remove the wiper fluid bottle and charcoal canister or whatever it is under the expansion valve (3 lines go to it, for gas tank fumes). the small nut can take a crescent wrench and the big nut you will need a 22mm, on the expansion valve.

DO NOT PRY ON THE HEATER CORE LINES WHERE THEY COME OUT OF THE FIREWALL AT ALL OR YOU WILL BE REPLACING THAT TOO BECAUSE IT CRACKS WHERE THE TUBE ATTACHES. THE COOLANT LINES CAN STAY ON.

You have to do an 1/8 turn at a time with the 22mm on the big nut. Turn wrench flip it turn it flip it. Go from underneath with the 22mm.

Use vice grips to hold the expansion valve.

cruiser54

I'm not doubting your description of the "right way".

But, I'll tell you what I've done on 4 Jeeps over the last 6 years and they all still blow 38* in Arizona summers.

Evacuate the system.
Add Pag oil for the 134A.
Charge with 24 ounces of 134A using the adapters.

diskman

Only use PAG oil if you are flushing out all traces of the original mineral oil! Introducing PAG and mineral together is hella bad. Ester oil is compatible with mineral oil and r134a.

cruiser54

Well, I guess I'm doomed.

It was some kind of pag oil for doing conversions.

ajpulley

Looking back at this, would anyone with an '87-90 be able to give input on the hose ends for each of the four a/c hoses? I'm having new ones made because I can't find replacement hoses. The remainder of the components (evaporator, type I condenser, compressor, dryer) are replacements, but of the original design. I also have forgotten when end of the receiver dryer goes where.

Liquid Lines
Condenser < > Dryer (#6 hose)
#6 MIO (Dryer end, Top or Bottom?)
#6 MIO (Type I, depends on replacement condenser configuration)

Dryer < > Expansion (#6 hose)
#6 MIO 90° (Dryer end, Top or Bottom?)
#6 MIO 90° (Expansion end)

Vapor Lines
Expansion < > Compresser (#10 hose)
#10 90° MIO
#10 90° MIO

Compresser < > Condenser (#8 hose)
#8 MIO (Type I, depends on replacement condenser configuration)
#8 90° MIO (compressor end)