intermittent a/c clutch

[mrbrdodson]

I posted something in the problems forum but I have a generally impatient mentallity...My a/c does not blow cold at all. I did some looking around (mind you I don't know much about a/c) First off I found that someone along the way had removed a two pronged vacuum thingy (sorry) from I think the vacuume relay? Basically there were two nipples coming out of a big thing on the pass. side of the truck and a rubber line that clearly went on there. Some removed that and plugged the line up with two bolts. I replaced that. The a/c clutch cycles on and off maybe every 3-4 seconds. I'm guessing it is some sort of relay but I'm also reading that it could be air gap on the clutch. Any ideas or advice would be great.

[forddieseldoctor]

Sounds to me like it may be low on freon. That is the most common cause of frequent and erratic clutch cycling.

[mrbrdodson]

That seems to be the answer I keep coming up with during all my highly scientific research on the internet I did pick up a can of 134 earlier and put some in but was afraid to put too much in and wasn't reading the gauge correctly from what I can tell. Seems like I need keep adding until the clutch engages for a more reasonable amount of time. Thanks for the advice.

[mrbrdodson]

I added a second bottle of 134 along with a bottle of stop leak. Not sure why the freon leaked in the first place but the clutch seems to remain engaged and the air is definately cooler now. Thanks again for the advice...hopefully problem solved for now.

[forddieseldoctor]

Stop leak is horrible for your a/c system. It plugs up stuff that it shouldn't.

[jd4010]

Originally Posted by forddieseldoctor

Stop leak is horrible for your a/c system. It plugs up stuff that it shouldn't.

TOTALLY agree with this! To me, stop leak of any sort whether it be for A/C, oil or coolant leaks is just asking for further issues elsewhere down the road.

Best thing to do with the A/C leaks is to find the source of the leak and repair/replace accordingly.

[mrbrdodson]

Oops...well I guess I'll have to cross that bridge when I get there. The AC is working great now though.

[Acidsniper]

Yeah stop leak is the worst thing you can put into an A/C system. You can go to most local shops and get a recharge done from anywhere from $100 - $250 (as long as it's 134a and you don't have any problems with your system) depending if you just need a top off or a full evac & refill.

Lots of people end up causing more damage and or problems with their A/C systems by doing the DIY kits as they typically:

1) Turn the can upside down instead of holding it upright causing the A/C liquid instead of the gas to enter the low side of the compressor system or heat up their freon can to try and speed the process up (a "normal" recharge from a freon bottle kit takes 10+ minutes)
2) Overfill their system with freon (too much or too little and your A/C won't work) Most modern vehicles take around 2 lbs of refrigerant (more or less depending on the sytem) and rarely will take more than 2 cans of 134a unless you have a serious leak
3) Mix and match R-12 and R-134a, this is really bad joo joo and is more prevelent in <97 model year vehicles (although some 2000+ vehicles were still manufacturered with R-12, there will be a sticker no your evap, compressor or near your A/C system telling you what your system is charged with)
4) Put "stop leak" chemicals in their systems that don't actually have a leak causing intermittent problems with the condenser, compressor, evap system, etc
5) Severely scew their refrigerant / oil ratio causing excessing wear or excessive heat within their system leading to failures, plugs, etc

In general, if you're having A/C issues, take it somewhere and have it evac'd and refilled, if needed or just a straight out refill. It'll not only make your A/C system run more efficiently but it'll also save your compressor and thousands in repairs down the road.

[HAM_RADIO_MAN]

The next bad thing people do is, that they let their system run dry and get full of air. So now the system gets filled with freon and air and the head pressure is sky high and no one knows why. The vacuum pump is your best friend. A cooling system is made to have oil and freon in it and nothing else.

[justinmix]

Trace all your ac lines and look for any fittings or areas that look oily. Usually if you have a big enough leak it will push out some oil around the leaking fitting. Take a flashlight and look in thru the passenger side wheel well. You can see the AC compressor thru here. I've found the o-rings on the compressor leaking before.

Another problem spot is the actual high and low side fitting shrader valves. Especially if the caps are missing off of them. These can have a slow leak and not really show signs of leaking. You can usually tell if these are leaking if you have the caps installed. Run the ac for awhile then remove the caps. If they pop or have pressure when you loosen them then the shrader valves are leaking.

That being said, I agree with what everyone else has said so far. AC can be finicky. If you can't see any obvious oily spots then the only way to find the leak is with an electronic sniffer. You can put dye in the system and check for leaks with a black light but the leak will have to be rather big to find it.