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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: dirrty d84 on May 30, 2006, 10:39:00 am

Title: air conditioning question
Post by: dirrty d84 on May 30, 2006, 10:39:00 am

I am having a problem with my air condition. When i turn it on, the compressor kicks in and out. Air blows but it isnt cold. What do i have to do to make it work? I was also considering switching it to the newer r-134a. But i am unsure of what all would need to be done and how much it would caust or if it would be worth it. Any help would be great since its startin to warm up around here.

Title: > air conditioning question
Post by: Lt.Del on May 30, 2006, 04:06:00 pm

First question:  the compressor keeps kicking in and out and air is not cold.....it is not charged enough.  You need to add more charge. This is most likely the cause. You should invest in some manifold guages so you can see the pressures of the high and low lines. that'l tell ya. YOu can get a set for 70-80 bucks.

The conversion to r134a involves a complete flush of the old freon.  Flush the condensor, evaporator and all lines.  replace the receiver/drier, compressor and orfice tubes. Then buy the two connectors, one for high line, one for low pressure line. They just screw on the old connectors.  

Then completely vacuum the system until it holds 29.9 psi.  Hook up the blue (low) and red (high) lines of the manifold guages. Take the yellow line of the manifold and connect it to the can of 134a, use enough cans (pounds) as called for for your vehicle.  

a piece of cake.

SgtDel

Edited by: SgtDel at: 5/30/06 6:44 pm

Title: Re: > air conditioning question
Post by: VileZambonie on May 30, 2006, 07:50:00 pm

caust?  It is easy but you will need to have the system recovered and then vacuumed down to remove any moisture. Once you open the system it needs to be vacuumed once again, then you can charge it with R134a and add about 8 oz of ester oil with dye tracer. R134a molecules are smaller and will tend to escape faster through barrier hoses and o-rings but it's much cheaper than R12. So if you have access to the right tools then it is a do it yourself job if not, start shopping around...

Title: Re: > air conditioning question
Post by: Ziptar on June 10, 2006, 07:22:00 am

Cheaper way to go maybe. Check for A/C specials with local shops.

Around here there are several shops that do an "A/C Service" for ~$20. They fill the system with up to 1lb of freon and check for leaks.

So for $20 and an hour of your time you'll at least know where the problem lies.

or not..  The last three Volvo's that my wife has owned have all had the same symptoms of the cycling compressor once a year. We take it in for the $20 service, they add a 1lb of freon check for leaks, and they find none and say basically "See you next year".

I need to get the A/C going in the 79, the PO said he needed to recharge it once a year. I plan on starting with a $20 service and going from there.  

1979 Silverado C10 w/ Olds 5.7 Diesel

85 C10 Custom Deluxe