I’ve never had a Cherokee with working AC I usually buy it broken then it never really gets hot enough to really care. This time I’ve decided to replace all the missing parts so I can be cool for that one week a year we get in Washington.
My old 89 lost some things when I replaced the engine the condenser broke then I threw out the receiver drier and the muffler hose. Here is the list of new parts.
Parallel Flow condenser 10.5”x27”
Receiver/Drier
Cutoff switch
Muffler Hose
90 Degree Conversion Fittings
3 12oz cans of r134a
Can Tap
2x8oz PAG 100 compressor oil
Hecat Safe Flush
O-ring kit
Nylog O-ring lube
Conversion hoses for my existing gauges
Most of the parts are from ackits.com the rest are from various places.
I started by pulling the compressor, battery, and battery tray. Then I did an oil flush of the compressor. The fittings were removed cleaned up and installed new o-rings and conversion fittings. The compressor was turned upside down in a pan and turned over with a ratchet about 15 times to drain out the old oil. I turned it back up and added 4oz of the new pag 100 in the suction side while turning the compressor. Drained it again then repeated the whole process. After it was flushed I added 7oz of new pag 100 oil reassembled and put it back in the vehicle. The other ounce of oil was later put in the Receiver/Drier
After installing the compressor I removed the grill and the top plate that holds the radiator in place and installed the condenser. Last week I did a trial fit and made some brackets. The ac lines didn’t quite match up two inches were removed from the larger hose and some new bends had to be made.
The new muffler hose was also too long. About 3 inches had to be removed. More cutting and welding.
Flushing lines is a big mess I used a sprayer bottle filled with Hecat Safe Flush to get the fluid in. Then used dry filtered air to blow it out and a paper towel on the other end to catch the fluid. I did this three times in different directions and the last time kept blowing until it seemed like it was all out and dry. Things you cannot flush this way hoses with mufflers, condensers, compressors, receiver driers, expansion valves or orifice tubes they need to be replaced or cleaned in some other way. All the hoses are installed with new r134a o-rings coated with nylog and the vehicle is put back together.
Next is the vacuum and charge. The gauges are attached with high and low side valves open and the compressor valves turned in half way. A vacuum is pulled for one hour after 15min you can turn the pump off to see if it holds but this will only tell you if there is a major leak. The gauge valves are closed and the vacuum pump is removed. A can of r134a is attached and the gauges are opened. To keep the pressure up the r134a it can be put in some warm water. When it’s empty close the gauges install another can. Start the engine put the AC on max and slowly open the low side gauge the high side should never be opened. When you get to the third can watch the pressure and the center vent temperature and get it in the range on the chart. Once it’s in the proper range keep adding a little bit to see if the temperature drops any more. When you hit your lowest temperature and it seems to level off close the gauges. Back off the compressor valves so the service ports are closed remove the gauges and install all the caps. You now have a charged ac system.
When I was done I had a little bit left in the last can. When converting a system you will use about 90% compared to r12. Final low temp 42°F on max and seems to keep about 45°F driving around. Low side 16psi high side 187psi.
I’ve always had a fascination with refrigerant systems and I even got a little deep into it building cooling systems for computers. I’m not an automotive AC mechanic so my procedure may not be 100% correct. This worked well for me and others may have different opinions on how to do it.
My old 89 lost some things when I replaced the engine the condenser broke then I threw out the receiver drier and the muffler hose. Here is the list of new parts.
Parallel Flow condenser 10.5”x27”
Receiver/Drier
Cutoff switch
Muffler Hose
90 Degree Conversion Fittings
3 12oz cans of r134a
Can Tap
2x8oz PAG 100 compressor oil
Hecat Safe Flush
O-ring kit
Nylog O-ring lube
Conversion hoses for my existing gauges
Most of the parts are from ackits.com the rest are from various places.
I started by pulling the compressor, battery, and battery tray. Then I did an oil flush of the compressor. The fittings were removed cleaned up and installed new o-rings and conversion fittings. The compressor was turned upside down in a pan and turned over with a ratchet about 15 times to drain out the old oil. I turned it back up and added 4oz of the new pag 100 in the suction side while turning the compressor. Drained it again then repeated the whole process. After it was flushed I added 7oz of new pag 100 oil reassembled and put it back in the vehicle. The other ounce of oil was later put in the Receiver/Drier
After installing the compressor I removed the grill and the top plate that holds the radiator in place and installed the condenser. Last week I did a trial fit and made some brackets. The ac lines didn’t quite match up two inches were removed from the larger hose and some new bends had to be made.
The new muffler hose was also too long. About 3 inches had to be removed. More cutting and welding.
Flushing lines is a big mess I used a sprayer bottle filled with Hecat Safe Flush to get the fluid in. Then used dry filtered air to blow it out and a paper towel on the other end to catch the fluid. I did this three times in different directions and the last time kept blowing until it seemed like it was all out and dry. Things you cannot flush this way hoses with mufflers, condensers, compressors, receiver driers, expansion valves or orifice tubes they need to be replaced or cleaned in some other way. All the hoses are installed with new r134a o-rings coated with nylog and the vehicle is put back together.
Next is the vacuum and charge. The gauges are attached with high and low side valves open and the compressor valves turned in half way. A vacuum is pulled for one hour after 15min you can turn the pump off to see if it holds but this will only tell you if there is a major leak. The gauge valves are closed and the vacuum pump is removed. A can of r134a is attached and the gauges are opened. To keep the pressure up the r134a it can be put in some warm water. When it’s empty close the gauges install another can. Start the engine put the AC on max and slowly open the low side gauge the high side should never be opened. When you get to the third can watch the pressure and the center vent temperature and get it in the range on the chart. Once it’s in the proper range keep adding a little bit to see if the temperature drops any more. When you hit your lowest temperature and it seems to level off close the gauges. Back off the compressor valves so the service ports are closed remove the gauges and install all the caps. You now have a charged ac system.
When I was done I had a little bit left in the last can. When converting a system you will use about 90% compared to r12. Final low temp 42°F on max and seems to keep about 45°F driving around. Low side 16psi high side 187psi.
I’ve always had a fascination with refrigerant systems and I even got a little deep into it building cooling systems for computers. I’m not an automotive AC mechanic so my procedure may not be 100% correct. This worked well for me and others may have different opinions on how to do it.
