New AC Compressor/Clutch Help

[Josh318]

I just installed a new Air Compressor/ Clutch in my 98 5.2L V8.
The air works great, however, when the truck idles, at a light, or stop sign or whatnot, I can hear the clutch engage and I hear a churning/rubbing noise. Is this normal? I don't remember hearing it when I had AC last fall. The FREON is a little low. Do I need to add some kind of oil? When I put FREON in, I used a kit from Autozone, and the freon in the kit had stop leak, and a little bit of oil.
How can I get the churning noise to quit?

[fredjacksonsan]

So when the clutch engages, you get a click-whirr-chrrrrrr sound, right? Low on freon would be my guess. If it's REALLY low, it will cycle rapidly.

[Josh318]

Exactly! I'll try adding more Freon. Since it's a new Compressor/clutch, I have to fill the Freon Completely. I've already put in 3 Cans of it, approximatly the size of a 20oz bottles of coke. How many should I expect to put into it? It was 70 degrees out when I did it, and after all 3 cans were put in, the gauge was only at 32.

[fredjacksonsan]

While I don't know the exact specs, 32 sounds low. I usually just fill until the little bottles can't put any more in.

I retrofitted an old car system to R34 last summer, and it took 6 cans...... (well, 5 1/2 anyway)

[Josh318]

Okay, I'll add more than. Thank-You

[fredjacksonsan]

No sweat! (Of course if noise comes back after adding......)

[A97]

I never messed with the kits from autozone before so i dont know what is available, however i do know that unlike r-12 where the more freon you have the colder the a/c is, r 134a is`nt that way. You should have a decal under the hood which will tell you how many lbs/ oz. to put in. with r-134a too much or too little will make it not work properly.where i work we use a vacuum pump to remove all the air from the system and a digital scale to put the exact amount back in. someone who works with a/c frequently can also do this just buy looking at the gauges but i imagine since they sell these kits now at autozone for some time now it should all be in the instructions

[fredjacksonsan]

I've never had a problem filling it up until the bottle wouldn't fill any more, but gauges are in order to be precise.

[rksnc]

A 98 model will be r134a. They have been that since 95. I can tell you that it will only hold about 2lbs. 32oz at the most. You need gauges You should have around 250psi on high side and 24-27 on the low side. This is with the blower on high and engine speed at least 1500rpm's. Oh yea were you able to pull a vacuum on the system. This is a must. Air and moisture is a ac worst enemy. Oh yea why did compressor go bad? Did you change accumulater? Did you change the orifice? All theses thing need to be done or the problem will happen again.