saber

I'm looking at a 78 with a bad compressor. Is a 78 the old style refrigerant that you need to change the while system?
Anyone know what this costs?
Thanks in advance.

Tampa Jerry

No one will give you an estimate of cost until the system is tested. That said, you can purchase a replacement Pro 6 compressor for about $250. R-12 is costly. Are the hoses OK, how about the condenser and the evaporator? Has the system been open for a long period of time? Did the compressor fail and send flack throughout the system? The system may have to be internally flushed. Lastly, it should be evacuated and oiled and filled. I would find a competent old school AC shop that can give you estimates for repair for both R-12 and R -134A. You really want to do it once. I feel for you as I am north of you in Tampa and the temperature here is already in the mid 90s. Jerry

Kerschmolar

Refurbished AC on two 78’s about 5years ago. The original service manual for 79 is excellent for AC; 78 and 79 AC are excactly the same. 78 manual includes other Chevy models, so you need to sort thru the info more. Replaced compressor($200-300), hoses($100), accumulator and orifice tube($50), Freon/r12($300 on fleabay). Other items; mineral oil/dye, O-rings/seals and Nyloc, suction port filter, flushing solvent. Also include material to seal air duct connections and optimize insulation. Special tools; gauges with hoses, Nitrogen bottle with regulator, vacuum pump, a few misc.(about $500 for tools). Total for parts about $1,000; could be as much as $2,000 if evaporator, condenser or control parts are needed. Probably double everything if you have someone else do the work.
Lots of previous posts here on AC work and problems encountered.
Charlie

Greg

Charlie is right on with his estimate. But all that investment will be for nothing if you do not remove the evaporator core and clean out the 45 years worth of road debris and general crud that gets packed in there.



Thanks to ukjohn for this great image!

kanvasman

I also agree with he above. There is a lot of stuff here, a lot of OLD stuff, starting with the stuff in the heater box. AND while you are there...I would suggest replacing the evaporator and heater cores. That is a big job. As said, you only want to do this once. If you get your entire system evacuated, then recharged, only to find in a few months that the old eval core can't handle the pressures, you will have to do it all over again. Pay the man now, or pay the man later, but eventually you have to pay the man. Especially if the man lives in Florida. Good luck.

interpon

The problem you have is no known history..
if you do get it..start with gauges and see where the leaks are with compressed air.
replace any suspect hoses and leaking components.
if you want to stay original the
replace with new premium compressor about 350 i paid napa
if not original then i would consider sanden compressor add $ for bracketry
3 year warranty..and had to use warranty with napa
accumulator removal replacements about 75 bucks
other seals orifice etc. flush solvent etc 100 bucks..

as stated above gauges vacuum pump 300 ish..

freon nos cans about 4 ..30 bucks a can r12…
134 walmart 7 bucks a can..
cuss jar $
bandads $
new wideazz crescent wrench for accumulator 20 bucks

Windows down even top off i often run ac when not rolling
diy..very satisfying..

saber

The compressor is disconnected and off car. They are asking a premium for this car looks like a pass.

Thanks