AC Problem Help Needed (8 Viewers)

[YngTLCOwner]

So this morning I went to have new freon refilled for the truck. Before doing this the truck on hot days would not allow the a/c to run. However, when the temps cooled down the a/c would start right up. I thought by putting in new freon that it would fix the problem. So far it seems like it did the trick. However, the guy that did it said that I have a leak somewhere. When running the A/C w/ truck parked the rpm would fluctuate up and down. The truck would not be able to just sit idle. Anyone know what could possibly be the problem? Sorry never had this type of issue before. Any help or suggestions would be appreciated.

Thanks
Steven

 

[cruiserdan]

So,

A/C works "when temps are cold" but not warm?


Engine running hot (+226 degrees F) and the A/C cut-out is activated?

 

[elmariachi]

Anyone know what could possibly be the problem? Sorry never had this type of issue before. Any help or suggestions would be appreciated. ThanksSteven

By design, the idle-up change is tied to the compressor kicking on and off. If the system was low on freon, it could cause the compressor to kick on and off, which would cause the idle to jump up and down. Look under the hood with the AC on max and see if the idle movement is tied to the clutch kicking on and off (on the front of the compressor pulley). If you have plenty of freon and its doing that, the high pressure cutoff switch may be kicking in. This could be caused by a failing expansion valve. The FSM shows you (or a shop) how to diagnose the exact problem with a set of AC gauges. That's the best place to start diagnosing rather than guessing. One other thing....is it making water...is water dripping out from the passenger side when the truck is running with AC on max?

 

[YngTLCOwner]

Dan,
The a/c was cutting out when the temps outside were above 80 degrees. Wether I would be driving the truck or if the truck was just parked the ac would not work when it was hot out. Now after recharging the freon the a/c works. However, the truck now when parked and a/c running the rpm fluctuates up and down regularly. The truck temp gauge is looking normal. No signs from the temp gauge showing overheating or anything in that manner.

 

[YngTLCOwner]

By design, the idle-up change is tied to the compressor kicking on and off. If the system was low on freon, it could cause the compressor to kick on and off, which would cause the idle to jump up and down. Look under the hood with the AC on max and see if the idle movement is tied to the clutch kicking on and off (on the front of the compressor pulley). If you have plenty of freon and its doing that, the high pressure cutoff switch may be kicking in. This could be caused by a failing expansion valve. The FSM shows you (or a shop) how to diagnose the exact problem with a set of AC gauges. That's the best place to start diagnosing rather than guessing. One other thing....is it making water...is water dripping out from the passenger side when the truck is running with AC on max?

There is no water leaking on passenger side at all. I will go out and try looking again under the hood and see if it is what you are thinking. Thanks for your quick response.

 

[elmariachi]

There is no water leaking on passenger side at all. I will go out and try looking again under the hood and see if it is what you are thinking. Thanks for your quick response.

IF...its full of freon...and IF its not making water, then the system is not circulating freon, which would suggest that there is blockage. You could have blockage in the evaporator core, the expansion valve or even the condensor. Generally, gauges will tell you which of those it is. Also, there is a sight glass straight behind the battery against the driver's fender...a little square box on the AC pipe that has a glass eye on it. Have someone rev up the engine for a couple seconds with AC on max ( or do it by hand on the throttle linkage) and then let off and see if you see bubbles passing through the eye.

 

[cruiserdan]

The idle does kick up when the compressor kicks on. The ammount of condensation, if any, will depend on the humidity. Around here very little water shows up most of the time.

 

[elmariachi]

Around here very little water shows up most of the time.

Good point about humidity.....and I trust you know how lucky you are there on the high desert plateau.

 

[cruiserdan]

Good point about humidity.....and I trust you know how lucky you are there on the high desert plateau.

Indeed....

 

[YngTLCOwner]

So from quick observation there are no bubbles showing up through the glass that you had mentioned. When a/c is on high and the idle changes up and down I noticed that the round shaped object the one of the belts is on spins and then stops. It seems when the compressor kicks on it will spin for a few seconds then stop and all at the same time the idle is moving up and down. I appologize I don't know all the exact parts and and don't have a fsm in front of me. I will go to a local shop and see if they can diagnose /w the gauge.

 

[elmariachi]

So from quick observation there are no bubbles showing up through the glass that you had mentioned. I will go to a local shop and see if they can diagnose /w the gauge.

If its full of freon, a lack of bubbles suggests poor or no circulation. That could be caused by a clogged evaporator, clogged/faulty expansion valve, or clogged condensor. Gauges will tell you which, though it would be helpful to have someone fax you the diagnostic pics of the gauges from the FSM if you don't have one (mine's at home). My guess is its the expansion valve, only because I have had this issue with two other late model Cruisers. It appears your compressor is kicking on, but the high pressure being caused by the restriction is kicking it back off too soon. Here's a quickie tutorial I typed up for you:

Quick AC basics....when the AC is on, the compressor compresses the liquid freon, which makes it a hot gas. Pressure forces the hot gas through the condensor (the radiator looking thing in front of the radiator) where it is cooled by airflow and condenses into a liquid. That cooled liquid travels into the cab and goes into the evaporator core under the passenger dash, where the AC fan blows across the cold core and out the vents. The expansion valve holds the cold liquid there briefly then pressure opens the valve and the liquid freon returns to the compressor for another run.

 

[YngTLCOwner]

Elm,
Thanks a lot for your help. I am putting in a call to a friend to see if he can get a copy to me. Hopefully, its just the expansion valve. Would replacing the expansion valve be something you could do on your own or something that should be done at a shop?

 

[elmariachi]

Would replacing the expansion valve be something you could do on your own or something that should be done at a shop?

Well, I changed mine in the middle of the ^%$#$ desert at the entrance to Area 51 between Las Vegas and Tonopah, Nevada with a few basic tools and eroding daylight. Of course I had to wait until Tonopah to get to a vacuum pump and freon, but it worked.

IF ITS THE VALVE, it involves removing the passenger glove box and numerous items to reveal the evaporator core. It also requires that you first capture the freon in the system (mine leaked out) and then be able to pull a vacuum to put the freon back in (I'd have a shop do both if you decide to do this yourself). I would say its a two job. You need the book, tools and lots of confidence. I think it took me about 3 hours to remove the stuff, replace the valve and reassemble. Probably not a task for a novice.

And you need to plan on replacing the dryer (the silver cannister behind your ARB bumper, driver's side). Once you open the system and expose it to moisture, its toast.

 

[OZCAL]

Data point - in coastal California and the central valley it is usually very humid and you get a steady trickle of water from the 80's A/C condensation. Puddle in the parking lot. But if you are inland desert (e.g., Palm Springs) or high desert (e.g., eastern slope Sierra Nevada) you might have very little condensation make it to the pavement.

Where are you in SoCal, YngTLC?

David

 

[YngTLCOwner]

I will take the truck in and have them work on it. Hopefully wil have this all fixed by end of today. Thanks again Elmariachi for your help. Will have the guys at the shop looking into the Valve.

 

[YngTLCOwner]

I am in Alhambra/Pasadena area.

 

[elmariachi]

I will take the truck in and have them work on it. Hopefully wil have this all fixed by end of today. Thanks again Elmariachi for your help. Will have the guys at the shop looking into the Valve.

You are welcome, just be sure and post the outcome. Also, I'd like some pics and info via email of your rear outlet install if you have any.

 

[YngTLCOwner]

Dan,
What would a smart shoppers price be for the items needed to replace the evaporator valve and the ac dryer?

 

[YngTLCOwner]

You are welcome, just be sure and post the outcome. Also, I'd like some pics and info via email of your rear outlet install if you have any.

I could take pics of the set up but as for the install the previous owner had installed it. I can look into it and see if he had it set up in any specific way. I will email you w/ any info I gather and will send you a pic of the outlet in the rear. Thanks again for your help.

 

[whodat]

Dan,
What would a smart shoppers price be for the items needed to replace the evaporator valve and the ac dryer?

You should PM Dan for the smart shopper prices. Not for public viewing