2004 Foed Freestar, the A/C has started blowing less than cool air in the past sveveral days. I'm assuming its low on refrg. but how does one check by visual inspection? If it is low will a simple re-charge kit w/guage and super dupper leak sealant do the trick? I saw a kit at Advance Autoparts for $54.00 manufactured by Interdynamics. It had a guage w/trigger release for can content and three 12oz. cans of R134a. Will this kind of kit work? Thanks for any help offered.

 

Actually the first thing to check is the clutch gap on the compressor. It's a wear item that can manifest itself as weak AC quite often. Here:

Find the AC compressor under the hood. If you don't know what is what, this is the belt-driven accessory that has a pulley that typically looks like it has 3 low ***** on it. That's the clutch plate. It helps to do this when the weather is warm - at least 60F - so that the system has enough pressure to operate correctly. Low temps= low freon pressures, and the system won't run as it trips the low pressure cut-out switch. Start the car, put it on MAX AC to ensure the compressor will run (give it 10 sec to make sure it kicks on). Now go look at the compressor. Is the clutch turning with the pully or is it stationary? If it is not turning, give it a tap on the front face of it (towards the pulley) with a screwdriver handle or broom handle or stick. OBVIOUSLY you need to be careful not to get anything (tool/hand/hair/etc) caught in a belt or pulley when you do this. If the clutch suddenly engages when you do this, then the clutch gap is too wide from wear over time. The fix is to pull the clutch and remove one of the clutch shims on the compressor shaft to tighten up the gap and bring it back in spec again so it works. That is easy to do.

You need to hold the clutch still so it does not turn. Wedging it with a pry bar or something helps. Remove the center nut/bolt and then use a couple screwdrivers or flat bars to pry the clutch off by working around it in a few places bit by bit. You will see a couple thin small washers on the shaft - they might be hidden up in the clutch or on the compressor - depends on the model. Typically removing one of them will do the trick. Normal clutch gap is 0.014-0.030" (But that does vary slightly by model). If there is a really thin one and a thicker one, you probably want to pull the thicker one. Reassemble and try it out.

Avoid sealants in AC systems. AC system testing requires a guage SET with 2 gages - low and high side. The "Magic In A Can" with a low pressure gage only, tells you very little.

 

Thanks DSTIG1, I will give this scenario a shot and see what happens. I bought the kit just in case but will definetly try you suggestion first. Thanks again for the help

 

Take that kit back to the store. The additives and sealers in them are little more than snake oil and can actually damage your system. There is also no way to determine the proper refrigerant charge with just the cheap Low side gauge.

Many Auto Zone stores will loan/rent a manifold gauge set. With that you can monitor both sides of the system and better determine the refrigerant charge
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Obviously, if the system is low on refrigerant you have a leak that should be repaired. Leaks don't get "better". If the system is very low/empty of refrigerant, there may also be air in the system which can damage components. The system then needs to be pulled into a hard vacuum before charging.
There is much more to AC repair than "topping off" the refrigerant. Blindly adding refrigerant can cause expensive damage to a system that may only need a simple repair.

 

Ive worked on a many Freestar with catastrophic compressor failure so I would advise taking to the dealer or competent servicing facility to do a proper diagnostic.

 

I'm a free market kind of guy, but if I were going to outlaw just ONE product, it would be a/c sealants. I have two recovery/recycle machines that are always only one recovery away from destruction should I recover from a system with that JUNK in it.

 

I totally agree, Doc!
I just spent $800 to have my combo R12/R134a machine repaired due to sealer ingestion.