don’t do that !!

check autozone and pepboys for loaner tools


if you go to HF use a coupon and hopefully it is on sale too!

 

why are you saying all this ??

 

Because to properly attend to a flat a/c system it is necessary. Of course you might get by with just a recharge but you will be at risk on ruining the compressor or operating a system that is not to it full potential.

 

We weren’t told if system was ever totally emptied (flat?), so unless changing some components evacuate not required. Considering full extent unknown of system, why add that expense? Maybe a shot of oil, charge system and see how it does from there. It may then require all you say, right now I don’t think we know. I thought I missed something about the system that maybe you saw.

Of course my perspective is on the DIY. thrifty side. I don’t have and like to spend $. If that wasn’t an option, then just have whole system replaced and know where you stand from then on. All new 134 clean components.

 

I have a gauge set on the way from Amazon. It was not that expensive and I have a 1986 Z28 with the same problem so the set will come in handy.

I will hook up the gauges when it gets here and see where we are on the Low and High sides and go from there.

Thanks for all the great input - almost there !

 

I myself too am a diy and I’ve tried it by cutting corners but the only right way is to start from scratch with a proper flush especially if you are not sure of what has been done or how long it was down. I have learned to just do it right to begin with and do it once. I have everything to do the job including a vacuum pump, manifold gauges, and a flush canister.

 

Never were we told system was empty. That is not the only right way. Just one way. Starting from scratch isn't the only right way.

 

I have posted what I can to help the man.
Nothing else from me.

 

Does the vacuum pump also get rid of any refrigerant that is left in the system now?

 

Yes. The vacuum pump draws the system into a deep vacuum if done correctly and no leaks exist in the system. It will remove moisture, air and non condensable gas, and all the freon. If your system had zero pressure in it to start with then air and moisture got in. If you had pressure still then there was enough freon left to keep that out. This is why people are having a hard time answering. Since you have the compressor cycling on the low pressure switch now and assuming you still had pressure in the system to start with, then you either have a low charge or a restriction as was stated a long time ago in a post. When you get your gage set, take a look at low side and high side pressures. They indicate with both of the valves shut on the manifold. Only charge through the low pressure port and monitor discharge and suction pressures. You should be able to get the compressor to run continuously. Once it is running slowly add more refrigerant and monitor low pressure pipe temp and air duct temps. You should be charging with windows down and the a/c on high. If high side pressure climbs toward 300 and you still have no cooling to speak of, then the system has other problems. Air in the system will do this. Well, I am off to work and have given you some stuff to do.

 

good advice...
and it assumes whoever changed system over did it right and flushed out r12 mineral oil to the correct 134 oil...
thus others response and debate..
my system r12 still had freon but imagine more was added over many years as it leaks and no oil is replaced..bye bye compressor

 

a small leak that takes years (normal to some respect) to loose probably wouldn’t loose any oil to speak of.

 

i disagree..most leaks have oil trails...very slow leaks wouldn’t require a can a year at minimum

 

Doesn’t the Freon also have oil in it or should it be added separately ?

 

some do some don’t need to read the can

 

Well the Amazon supplier screwed up my order so I still have not received my gauge set. So I took a shot in the dark and added more refrigerant. It took two 14 ounce cans and now blows cold air down to 60 degrees. Problem now is that it makes a terrible rattling noise when running and I see that the belt has some slop in it. Any ideas?

 

personnaly i would put gauges on it...first and report..
that said....tighten belt...
60f where? Set how? What is outside temperature humidity? Did you add to low side with gauge? What was reading?

 

60 degrees F measured at the vent with a probe temperature gauge.
91 degrees F ambient temperature
81% relative humidity
charged the low side and low side pressure reading is about 50 psi.
Belt slip is only when the compressor is running. No slop with it off.

 

tighten belt..

sounds like you are probaly a little high..but oh well...not too bad ..need those gauges
try low fan max air center vent and when compressor cycles off, what was the temperature? Should be 38-46f r12 original.probably higher for 134...this at 2000 RPMs doors **** windows one or two open..

assumes all cooling shrouding in place..you should be dripping water outside passenger side..

pic of shrouding? Fan?

 

Temp is 60F with tops off and windows down. Same temp at center vent. There is a lot of water dripping from passenger side.
I could be mistaken but it sounds like the compressor clicks on and stays on.
I can try to get the belt a little tighter but just curious why there is slop only when the compressor is engaged.

Also still have the rattling noise issue.