[matt167]

My 1995 Cheyenne K1500 has A/C and is producing colder than ambient temp, but I'm not sure it's working right.. It is an R-134A system. I bought an EZ chill R-134A kit from walmart earlier today, and used it. Directions were vague, tho my dad has done tons of cars with the EZ chill bottles. I checked online for the directions even tho I remembered, it's been a few years since I'v helped him with 1... I found the low side port, and checked the preassure.. With the A/C on the compressor is cycling on and off. the preassure goes up to 45 PSI when the compressor is not running. when it hits 45 PSI when off. then it turns on, and runs for probably 20 seconds, and the preassure drops below 25 PSI and the compressor turns off.. I tried adding a little refigerant when the pump was running but it doesn't seem to take it.. However, I checked the vent temp with a non contact thermometer, and with the ambient temp at 80*, the vent temp was 66*, which I know usually vent temp is 58-60* optimally , but also heard that 25* colder is generally OK, and it's within range of that.. But is the compressor supposto cycle so quick?

[LATECH]

sounds low on freon,Duct temp should be colder and ambient temp is high enough to keep the compressor on more than off,25 pounds is low on the low side, add some untill the compressor runs more than it is off,then recheck vent temp. At 80 degrees ambient that system should be capable of 50 degree air easily. You need to run the system on recirculate after you add freon, measure the duct temp in the center vent after the system runs 5 minutes (after you stop adding freon ) so as to stabilize the pressures to be able to tell how well it will perform.After 5 minutes it should feel pretty nice inside.
Low side pressure should be 35-45 lbs, some of that depends on ambient temp , cabin temp, compressor health, evap and condenser efficiency...etc.
Without a high side gauge it can be hard to know what is happening in your system.
Make sure the freon you buy does NOT have oil charge in it. oil takes up space in the system that is needed for the freon to transfer heat, unless you have replaced a part or have blown a hose, no more than anounce of oil is plenty.

[matt167]

It doesn't have oil. just leak dye. Couldn't find any without..

How do I know it's taking the freon? The can still seems full and I tried pulling the trigger disconnected and it does nothing.. could the can handle be bad?. It's made by EZ chill, just has a gauge, a port to screw into/ puncture the can and a trigger.

[LATECH]

could be defective. At 25 lbs on the low side there should be plenty of pressure in the can to push the freon in. I usually dump liquid in the accumulator of a ccot system, with no trouble. Charges quicker, but thats just me, flat rate in a hurry.

[matt167]

I'll buy the bigger bottle with the hose attached then...

I would take it to an A/C shop but the only local shop, charges $100 to pump it full of stop leak and basically tell people to see them next year

[LATECH]

Yeah, dont go there. Stop leak is a rip off.It works ,on everything. Including AC machines, most shops wont touch your system once there is stop leak in it. Shame on those guys putting in stop leak,they are doing people a great disservice.
Filters for AC machines are pricy and one load of stop leak can cause lots of trouble.
After stop leak is put into a cars system, say then you have to open it up for a repair, stop leak cures all over the internals ,like the reed plate and rings in the compressor, orifice tubes and expansion valves, what a nightmare.

[matt167]

Got the bigger can w/ the attachment hose right on it. Still made by EZ chill, and otherwise the same, except it comes with the hose ( which is removable ).. Put it in today, and instantly could tell it was taking it.. Ambient temp at 90*, The can emptied at 35 PSI, which is low by the charts, so I may need more, but the compressor is staying on and my non contact thermometer is showing 29* out of the vents, so I'll leave it for a while.. Walmart sells the refill bottles for this hose too, there like $12, and the whole setup is $25... Tho I think I saved $75 and a headache of a stopleak mess by NOT going to the local 'pro'.

[LATECH]

right on