Need help with under dash air
 

I have a 1970 C30 with Climatic Air under dash system I am doing an r134a retro fit and I do not know how much 134a to put into the system. It does not have any labels. Any tips or rule of thumbs would help. The compressor is a York 209. Thanks

Re: Need help with under dash air
 

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Re: Need help with under dash air
 

I am not the A/C Guru but here is The way I understand 134a change over (anybody can chime in with better info) Drain as much old R12 oil out of the system Remove compressor from truck turn over and drain out old R12 oil ...add about 5oz of 134a compatible oil (ester oil) is what I think its called. Turn pulley and clutch about 10 times to get oil into compressor. Remount compressor.. Replacing dryer would probably be a good idea. The system hooked back up pull a vacuum on it to check for leaks...This is where I don't know specifics. How many #s of vacuum and how long?. Adding 134a is simply put in all it will take. If you have gauges and a vacuum pump you can do it all...I will take mine to have the last part done...Hope that helps....Ed

Re: Need help with under dash air
 

It will probably take about 2 cans. Put iit in till the sight glass clears up. With in running on high on a warm day, watch the sight glass. When it clears up shut the valve off.