So on my 98 Grand Cherokee I ended up evacuating the entire system and replaced the compressor. I vacuumed out all the air that might have gotten in, put it all together and charged the system. At first, the air condition worked great! However, it is not blowing very cold again. The air is some what cool but I know it can be a lot colder because on my other 98 Grand Cherokee the air condition blows ice cold. So I decided to try something.

I decided to rinse the condenser with the garden hose through the grill. After doing so, I got into the Jeep and the air condition was finally ice cold! So this leads me to believe that there isn't a block any where or any air or water vapor in the system. It is now obvious that the condenser is not getting cooled off properly. What should I do now? I am thinking I might have a bad fan clutch (the engine runs off a belt fan. There are no electric fans). Any ideas?

How far down did you vacuum and for how long? Does it cool better while driving? How much charge did you put in? What is your high and low side pressures?


So on my 98 Grand Cherokee I ended up evacuating the entire system and replaced the compressor. I vacuumed out all the air that might have gotten in, put it all together and charged the system. At first, the air condition worked great! However, it is not blowing very cold again. The air is some what cool but I know it can be a lot colder because on my other 98 Grand Cherokee the air condition blows ice cold. So I decided to try something.

I decided to rinse the condenser with the garden hose through the grill. After doing so, I got into the Jeep and the air condition was finally ice cold! So this leads me to believe that there isn't a block any where or any air or water vapor in the system. It is now obvious that the condenser is not getting cooled off properly. What should I do now? I am thinking I might have a bad fan clutch (the engine runs off a belt fan. There are no electric fans). Any ideas?

How far down did you vacuum and for how long? Does it cool better while driving? How much charge did you put in? What is your high and low side pressures?

I put exactly 25 ounces of R134-a back into the system. My mechanic who is a friend to the family told me the vacuum the system out for about a half hour or so or until the gauge read somewhere between 25 and 30. After about an hour, it read 28 Hg. I closed the center valve and shut off the pump and let it sit on the Jeep for about a half hour or so to make sure there wasn't any leaks. I came back and the gauge still read around 28 Hg.

Low side was at about 33 psi and the high side was almost 300 psi. These readings were taken on a 95 degree day.

Even at highway speeds, the air condition isn't as cold as it should be However, even at night time, it takes awhile just to get the Jeep to cool off. I've noticed at night time, on the other hand, that with the lower temperatures that the A/C can get pretty chilly, whether I'm driving on the highway on local driving.

It's all very confusing to me! This A/C has never done this until this year and right during a heat wave is when I am getting these problems :banghead:

Your pressures don’t look right. Mine gets 35psi on the low and 200psi on the high side on an 80 degree day and it runs nice and cold even today at 90 degrees. In your first post you said that you have rinsed the condenser with the garden hose and the a/c got ice cold, while it was wet I'm guessing. If you hook up your gauge set on the high side and hose the condenser down with water you will notice that your high side pressure will drop like a brick and since it dose not cool good at highway speeds we know its not an air flow problem which leads me to believe that you have a gummed up orifice tube.



I put exactly 25 ounces of R134-a back into the system. My mechanic who is a friend to the family told me the vacuum the system out for about a half hour or so or until the gauge read somewhere between 25 and 30. After about an hour, it read 28 Hg. I closed the center valve and shut off the pump and let it sit on the Jeep for about a half hour or so to make sure there wasn't any leaks. I came back and the gauge still read around 28 Hg.

Low side was at about 33 psi and the high side was almost 300 psi. These readings were taken on a 95 degree day.

Even at highway speeds, the air condition isn't as cold as it should be However, even at night time, it takes awhile just to get the Jeep to cool off. I've noticed at night time, on the other hand, that with the lower temperatures that the A/C can get pretty chilly, whether I'm driving on the highway on local driving.

It's all very confusing to me! This A/C has never done this until this year and right during a heat wave is when I am getting these problems :banghead:

Your pressures don’t look right. Mine gets 35psi on the low and 200psi on the high side on an 80 degree day and it runs nice and cold even today at 90 degrees. In your first post you said that you have rinsed the condenser with the garden hose and the a/c got ice cold, while it was wet I'm guessing. If you hook up your gauge set on the high side and hose the condenser down with water you will notice that your high side pressure will drop like a brick and since it dose not cool good at highway speeds we know its not an air flow problem which leads me to believe that you have a gummed up orifice tube.

I probably should have replaced that with the compressor, along with the dryer/receiver. I thought that the high side pressure was a little high but I thought that was because it was so hot out. I'll replace the orifice tube and while I have it all apart I'll replace the dryer/receiver too and see what happens. Thanks a lot!

Yeah most compressor companies will void your warranty if the dryer/receiver and orifice are not replaced. Save your invoices.

At this point you might want to take an extra step and flush the evap and condenser. Not sure about your 98, but on the 96 models the orifice is part of the liquid line that runs around the fender and is not serviceable. you have to replace the liquid line.


I probably should have replaced that with the compressor, along with the dryer/receiver. I thought that the high side pressure was a little high but I thought that was because it was so hot out. I'll replace the orifice tube and while I have it all apart I'll replace the dryer/receiver too and see what happens. Thanks a lot!

Yeah most compressor companies will void your warranty if the dryer/receiver and orifice are not replaced. Save your invoices.

At this point you might want to take an extra step and flush the evap and condenser. Not sure about your 98, but on the 96 models the orifice is part of the liquid line that runs around the fender and is not serviceable. you have to replace the liquid line.


Yeah I have the same set up as the 96's. I already picked up another line that runs around the fender. Haven't put it on yet, but I will be flushing the condenser and evaporator later this week. I'll let you know how I make out.

Yeah I have the same set up as the 96's. I already picked up another line that runs around the fender. Haven't put it on yet, but I will be flushing the condenser and evaporator later this week. I'll let you know how I make out.

Ok so I flushed the system and replaced the orifice tube and then recharged the system again. I am still getting the same results. I checked the high side pressure and it was really high again, almost 300. The low side, however, was at about 43. I decided to put a big fan in front of the condenser and then turned the air condition on to simulate highway driving. I checked the pressure again on the high side and it was 200 and the low side was about 33. I'm thinking that my fan clutch is bad. I have noticed that the Jeep has been running a little hotter than normal. It used to hover around 210 degrees all the time. Now it runs closer to the next notch over on the temperature gauge on the dash. The thermostat is brand new, including the radiator and heater core and temperature sensor. I'm really thinking that the fan clutch is going bad. What do you think?

i'd agree clutch fan your readings are way to high.so if you dont have an over charged system clutch is a good supect.Good Luck

33 and 200 is where is should be. I agree this does point to the fan clutch. I just dont understand why it did not cool well at highway speeds. Did it cool better with the big fan?

I wouldnt trust the temperature gauge on the dash too much, If you have a scan tool check the engine temperature vs the gauge that will give you a better idea if things are running hotter and how much.

Ok so I flushed the system and replaced the orifice tube and then recharged the system again. I am still getting the same results. I checked the high side pressure and it was really high again, almost 300. The low side, however, was at about 43. I decided to put a big fan in front of the condenser and then turned the air condition on to simulate highway driving. I checked the pressure again on the high side and it was 200 and the low side was about 33. I'm thinking that my fan clutch is bad. I have noticed that the Jeep has been running a little hotter than normal. It used to hover around 210 degrees all the time. Now it runs closer to the next notch over on the temperature gauge on the dash. The thermostat is brand new, including the radiator and heater core and temperature sensor. I'm really thinking that the fan clutch is going bad. What do you think?

33 and 200 is where is should be. I agree this does point to the fan clutch. I just dont understand why it did not cool well at highway speeds. Did it cool better with the big fan?

I wouldnt trust the temperature gauge on the dash too much, If you have a scan tool check the engine temperature vs the gauge that will give you a better idea if things are running hotter and how much.

After my last post I took the Jeep out for a run on the highway and the air condition temperature dropped real fast. When I first started out the air coming out of the vents was 62 degrees. When I put a big fan in front of the jeep it dropped down to 48. This is when I decided to take the it out for a run on the highway and the temperature in the vents went down even further to 45 degrees at 80mph. The slower I went, the more the temperature increased. I do have a scan tool and went and check the engine temp through freeze frame data when the Jeep was running in my driveway for 10 minutes or so and I was getting readings between 220 and 230 degrees. It is supposed to be around 210. The thermostat did open up and I had plenty of anti-freeze. This is when the air condition vents gave me a temperature of between 60 and 65 degrees again. I ordered a fan clutch and it will be in tomorrow. Hopefully this works.

After my last post I took the Jeep out for a run on the highway and the air condition temperature dropped real fast. When I first started out the air coming out of the vents was 62 degrees. When I put a big fan in front of the jeep it dropped down to 48. This is when I decided to take the it out for a run on the highway and the temperature in the vents went down even further to 45 degrees at 80mph. The slower I went, the more the temperature increased. I do have a scan tool and went and check the engine temp through freeze frame data when the Jeep was running in my driveway for 10 minutes or so and I was getting readings between 220 and 230 degrees. It is supposed to be around 210. The thermostat did open up and I had plenty of anti-freeze. This is when the air condition vents gave me a temperature of between 60 and 65 degrees again. I ordered a fan clutch and it will be in tomorrow. Hopefully this works.


Replaced the fan clutch. Everything is perfect now. Low side pressure is hovering around 40 and high side is slightly over 200. Air is cold and stays cold. Thanks for all the help man. I really appreciate it greatly.

Not a problem glad to help. Thanks for the follow up.

Replaced the fan clutch. Everything is perfect now. Low side pressure is hovering around 40 and high side is slightly over 200. Air is cold and stays cold. Thanks for all the help man. I really appreciate it greatly.