AC charge

[rt_hawk]

Just added 3 12 oz can of r134a in my truck to the low side. Still only got the gauge, a professional liquid filled gauge, to maybe 28, air is way colder though. Should I add more? Outside temp is 80, pressure should be 45 according to chart... Any advice is appreciated. The air worked before but not the best...

[Moto2four]

Was it comPlety out before? At 45 psi your running a 40 degree evap coil, which is what your looking for. I like to charge mine with the motor turning about 2000rpm.

[Turbostang500]

First, what was the reason for putting 3 cans in the system?
It is sealed so it should never escape. If it does, it is leaking. If it is leaking then dont put more in till you fix the leak.

[rt_hawk]

3 cans was needed to bring the pressure up to 25 at idle with ac set at max with Max fan. It was low before that. It worked but not the best. Now it's great, so I am assuming I'm good now that pressure is about 28 at idle?? I added one can and it was at 22, 2 cans, 24, 3 cans and it's now at 28psi at idle max ac...

[rt_hawk]

The air in my truck has been the same since I bought it 3 years ago. Ok, not great, if it's a leak it's very slow...just FYI. Before I could always hear my compressor cycling as well. Now it's on all the time with max ac. So I think I was just pretty low and the low pressure switch kept cycling the clutch/compressor.

[Turbostang500]

Your right about the pressure switch cycling the compressor clutch like that.

28 psi seems real low to me. It has been awhile but i thought low side should be around 40 for the system to run and under that, the low switch would shut it off.?
idk about that though. If your clutch is running, then the pressure switches are satisfied.

[Moto2four]

If its at 28 psi at idle, it's prolly 20-25 going down the road. I thinks your still low.

[rt_hawk]

Yea I don't know. I am worried that if I put any more in I'm going to blow a hose when it gets hot...air is way cold now. I did the ranger ac heat block off deal before and it helped but with the new 134a it's amazing now!...I don't have a high pressure gauge, I should probably get one to be safe. With 4 cans that's 2.75 lbs of r134a. What do the trucks hold? 2.2? The clutch stays on now...

[rt_hawk]

Just checked my father in laws 99 SD. Max ac, fan on full, pressure was 28 at idle, clutch on, pressure started dropping, clutch would kick off under 25, pressure would build to 35, then clutch would kick in again. I guessing he is low... I also shimmed my ac clutch a while back to the correct air gap...that was a year ago.

[Jeff. State]

What kind of symptoms were you guys having before this?

My AC blows good and cold for a few minutes and slowly dies away?

Is DIY recharging difficult?


Thanks.