Banks4004

I recently replaced all the old broken ac parts on my camaro. I added the correct amount of oil and bolted it all up. I bought a can of 134 refrigerant that was 17oz to start out. After adding the 17oz can to the empty system it was blowing cold, at correct pressure for the ambient temp, and the compressor was staying on. This is all great except from what I have read on this forum, in stores, and manuals the system should hold about 35 or so ounces. Should I be worried that I only put in about half that amount and it is working fine?

Thanks
Matt

sofakingdom

iTrader: (1)

No; you should just put in the rest. It'll work that much better later on.

Banks4004

Wont the pressure increase to dangerous levels if I add that much more?

jermdm

Look at the refrigerant capacity label located under the hood. I know on my iroc, its located on the blower motor housing. See what it says for the amount needed. Then you can convert the lbs needed to ounces. Probably be around 2 lbs.

Banks4004

my sticker is gone haha. And there is also a conversion from the original r12 lbs to 134a lbs. 134a is usually around 80% the capacity the r12 was. If it is 2 pounds then I would be getting closer after oil and everything. but the tech articles and service manuals say more.

Reid Fleming

iTrader: (2)

Mine was 2.25 lbs of R-12 originally. 80% of that would be 1.8 lbs. That's aprox 29 oz. The oil is measured separately from that. 6 oz I seem to recall.

When you first put refrigerant in, it tends to stick around in the accumulator for awhile. After a few minutes of it running, it should have spread around the system more. While the car may not cycle much if it's sitting in your driveway, it's also getting zero air flow over the condenser aside from what the fans are pulling across it.....Once you start driving down the road though, you'll have increased airflow (wind) plus the fans running. This will make the car short-cycle the compressor. So the car will seem fine when sitting at a long light or in the driveway. But rapidly cycle on the freeway.

17 oz alone of R-134a is too little for the system. Throw another 12 oz can in there and you'll be good to go.

Banks4004

ok thanks for the info ill probably get another 12. and I can always monitor the pressure while i add

89mulletbird

iTrader: (4)

It won't reach dangerous pressures if you have too much. What will happen is that your compressor won't be able to get the low-side pressure low enough to ever cycle off, resulting in increased wear of the compressor and potential failure.

Banks4004

In that case maybe I will leave it alone until the hotter weather. If it seems to struggle cooling I will add more.

89mulletbird

iTrader: (4)

Get a thermometer that sits in your AC dash vent, I think this is the best way to baseline how well your system is working.

l_dis_travlr

In the original post, I didn't see the evacuation step, i.e. vacuum pump.
If you started adding freon into a system full of ambient air, might explain
the quantity issue. If this is what you did, don't run this very long, because
the humididty in the ambient air will freeze, creating very harmful ice crystals.
(The purpose of evacuation is not lowering the pressure, so much as
boiling out the water/humidity. Remember the high-school chemistry
relation of the boiling temp. of water related to pressure...)

Good luck.

PS: Reid Fleming AKA Professor Kool in the Houston TGO community, knows his stuff.

Banks4004

I just added another 12oz and now the pressure is actually reading a little low still. Probably just took time like Reid Fleming said. But its blowing extremely cold air, and I wish I had a thermometer. So here's exactly what I did:

changed accumulator and condenser
vacuumed system and added new r134 (and correct oil)
got it working but found a small leak in the line off the back of the compressor
relieved pressure after the new line arrived and broke open the system before it all leaked out
changed the line (little more oil) and filled it up immediately after (with the 17oz) without vacuuming again (I'm at university and dont have the pump here)
worked great
just today added another 12oz

So I'm not sure if that was all the best protocol, but its working great now. hopefully it will last.