Hi, anyone think troubleshooting the AC system is a simple thing or should I leave it to the pros?

My AC stopped working a couple of months back...I added more freon and it cooled for a few days and regulated the compressor and then back to no cold air.

The compressor engages but it does so in a very brief mannner, engages, releases, engages, releases, only a few seconds in between and regular air blows out...

When I added freon the compressor went back to acting normal, would engage run for several seconds, felt like a much longer time than now and then release and it blew cold air....

I am thinking leak but have to admit, i have never messed with the AC system other than to add freon...

I suspect a leak but how do I find it? I added freon that was suppose to find and seal the leak but that did not work, same thing as regular freon, cold for a couple of days and then nothing.

What would be common leak points for this AC system, maybe I an start there. Like I said the AC clutch engages but releases a second or two later and then it tries again and again. If I put a can of freon it will work fine for a few days, will cycle normal and will not make the truck jerk back and forth sort of speak....

Other than the compressor itself, I am pretty confident that once familiar with the common leak points and or issues that I can change all other parts myself....

Where and how should I start?

Any ideas? any good leak detection tools out there, products?

Appreciate the feedback....

98 F250 XL

 

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i also added the die and was not able to find a leak. Eventually i started to just check odd areas. I tightened the schrader valve fittings for HI and LOW and that seemed to help. I had noted a bubble when i was looking for leaks with soapy water... I did add a can of the "leak sealer" the last time, and i have had good luck for the past 6 months. It was leaking out every 2 weeks.

 

Ok, your truck probably hold right under 3 pounds of refrigerant. You really need a set of gauges to check whats going on. Leak sealer will not seal leaks like they say waist of money. Check at compressor where big line (suction) goes in and little line (pressure). If you have a bunch of oil around the flange o-rings could be problem. If its in front where clutch of compressor is replace compressor but you need to have some one that has done this do it. It sounds like you have a bad leak with out using dye in the system you need to look for oil (remember oil leak is oil that is not in system and by adding more and more 134a pushes out oil and starves compressor causing it to lock up) check condenser in front of radiator and your not going to tear your dash out to do evaporator. Some systems use pag oil or poe oil. Compressor will short cycle from pressure switch as suction side falls off below so many psi (like 20) or so. so that could mean you are low on charge. With out gauges and pressure temp chart, temp outside at condenser you wont know whats in there. best way is to weight in a new charge recover oil in accumulator and start over before anything else once leaks are repaired. You can try to charge again and try soap bubble test get some leak finder or you dish soap out of spry bottle. I hope this helps

 

Its all good information, thank you. I am going to borrow a leak tester from my local auto zone, just not sure which one they have and I am going to perform a full visual inspection with spray bottle in hand to at least have an idea of what the repair is going to cost me...

I feel pretty comfortable try to change anything myself except the compressor, that sucker is just in an odd place to work from the top....