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My '79 is an a/c car but there is no compressor. It's black on black and with triple digit temps we are having there is no way I can drive the car without air. So I'm wondering if I should try to restore the factory a/c or just go with something like Vintage Air? From what I've read, the factory a/c is not all that great.
I have a 79 that I restored the air conditioning. Every last, little part of the entire system is new, I even went with a parallel flow condenser for the R-134A. It does pretty well on the freeway but starts to struggle in stop and go traffic.
It works good but definitely not like a modern car a/c
Last edited by Gralls4771; Jul 6, 2021 at 11:45 PM.
compressor is gone. mounts? hoses? condensor in front of radiator? these are frequently also removed. if only the compressor is missing, this sanden clone has the gm pad mount for our factory hoses. https://www.ebay.com/itm/303034153683 you can buy any sanden 508 or 709 and get the correct cyl head with the gm pad and save about 25 bucks. this adapter will make the compressor fit the r4 mount. https://www.google.com/search?q=corv...09121762469952 then you need an accumulator for about 40 bucks as yours has been sitting open sucking up mousture and a smaller blue Ford orifice for R134 and if nothing leaks, you may have functional air. oh yeah. belt...adjustable cycling switch for the slightly different R134 pressures. if you are not a knock-off kind of guy, the real sanden is about 100 more. you want a v-belt version. clutch-pulley is about 60 bucks to convert. but you still need the head for your OE hoses. https://www.ebay.com/itm/164854755494?epid=1585767315&hash=item26 621bf0a6:g:dWMAAOSwowJglZAH
Last edited by derekderek; Jul 7, 2021 at 07:44 AM.
My '79 is an a/c car but there is no compressor. It's black on black and with triple digit temps we are having there is no way I can drive the car without air. So I'm wondering if I should try to restore the factory a/c or just go with something like Vintage Air? From what I've read, the factory a/c is not all that great.
It would be good to detail what you have now..stock fan , electric etc..mods.. (pics good)
i agree with advice of going Sanden compressor.. i have original style R4 with R12 and 90 with sun lowest fan setting too cold so i go to non MAX setting, so it is a fact they are capable.. HOWEVER... (not counting aftermarket set ups) no experience with Sanden but they do have a reputation, and i would consider it if the R4 leaks.. (again) ..do not buy refurbs only new..
Everything MUST run properly
- airflow, all seals in place?
- clutch fan working properly?
- cooling system OK ? is the 195f thermostat still in it? try 180f
- a little reflective tape on evaporator helps.
- Hot water shut off valve recommended.. even with vacuum shut off (engine off vacuum lets go some hot water)
- mod the aux fan?
- proper oil and freon amounts?
- gauges to verify?
at idle now i get about a 3f rise compared to 2000 rpm and 40 MPH (seems ideal airflow and rpm for lowest temp) ...if you can get compressor to cycle at 1500 rpm (i just idle) fan low middle vent temperature between 38f and 46f you are at factory spec.
a few related threads..of pain and learning
Everything is pretty stock. Condenser is missing though. Compressor brackets are there. Heater hoses are bypassed so no heat. Maybe heater core was leaking so they bypassed it? Or maybe they just didn't want to bother with a shut off valve? It came from SoCal so probably didn't need the heater much. Anyway, looks like everything is there except for the compressor and condenser.
Everything is pretty stock. Condenser is missing though. Compressor brackets are there. Heater hoses are bypassed so no heat. Maybe heater core was leaking so they bypassed it? Or maybe they just didn't want to bother with a shut off valve? It came from SoCal so probably didn't need the heater much. Anyway, looks like everything is there except for the compressor and condenser.
if it was me?
new aluminum condenser
new sanden compressor and associated hose connections etc..
new accumulator
new orifice and o rings
pressure test, vacuum down overnight
134 with proper oil or r12 with proper oil. proper charge/ pressures.
again be good to know what else you have..
and oh ya.. check heater core for leaks and or hook up with shut off valve(s) or replace (big job but totally doable and you can fix other stuff ).. i know many leave off but it sure is nice to have in winter..and defrosting..or that chill in the night windows down..
It was 116F in Portland last week. Rehabilitated the ac on both of my 78’s last year. Reused the original evaporators and condensers; new ACDelco R4 compressors and r12. I did add lots of extra insulation, especially around the evaporator box and along the firewall. Electric fans probably help the condenser a little.
Self-stick high temp insulation
Didn’t need to use Max at all.
Driving around with the ac on norm and medium fan kept me cool and comfortable.
if it was me?
new aluminum condenser
new sanden compressor and associated hose connections etc..
new accumulator
new orifice and o rings
pressure test, vacuum down overnight
134 with proper oil or r12 with proper oil. proper charge/ pressures.
again be good to know what else you have..
and oh ya.. check heater core for leaks and or hook up with shut off valve(s) or replace (big job but totally doable and you can fix other stuff ).. i know many leave off but it sure is nice to have in winter..and defrosting..or that chill in the night windows down..
Good plan.
I've been driving my C5 instead of the C3 because the A/C in that works great! I would like to drive the C3 soon though and also in the cooler weather (it only snows here occasionally and melt very quickly) so heat and defrost will be required. I'll definitely run some water through the heater core to test it and if good, will run a shut off valve in the hose. Don't know if anyone has done it but thinking an electric solenoid controlled valve would be nice because winter weather temps can vary greatly here and you need heat in the morning and a/c in the afternoon.
It was 116F in Portland last week. Rehabilitated the ac on both of my 78’s last year. Reused the original evaporators and condensers; new ACDelco R4 compressors and r12. I did add lots of extra insulation, especially around the evaporator box and along the firewall. Electric fans probably help the condenser a little.
Self-stick high temp insulation
Didn’t need to use Max at all.
Driving around with the ac on norm and medium fan kept me cool and comfortable.
Good to know. Was thinking about converting to electric fans with shroud.
changing the thermostat from 195 to 180 will lower the temp at which the thermostat opens, but has no effect on engine operating temp. this is
is based on system design and condition.
I've been driving my C5 instead of the C3 because the A/C in that works great! I would like to drive the C3 soon though and also in the cooler weather (it only snows here occasionally and melt very quickly) so heat and defrost will be required. I'll definitely run some water through the heater core to test it and if good, will run a shut off valve in the hose. Don't know if anyone has done it but thinking an electric solenoid controlled valve would be nice because winter weather temps can vary greatly here and you need heat in the morning and a/c in the afternoon.
i agree. but around 30 psi. if it leaks it will spray air all over your rugs instead of water... condenser missing. https://www.ebay.com/itm/303589092019 parallel flow. you have the good evaporator with the orifice tube built in.
Last edited by derekderek; Jul 8, 2021 at 06:55 AM.
heater fan hasn't run in a while. right side wiper trough. look through that screen. you can see the squirrel cage of the blower fan. gaps around that screen let the mice in to make a nest in there. probably easier to remove the screen and stick a shop vac down there than to pull the fan out. if replacing the evaporator you can reach in there. from where you removed the evap.
Last edited by derekderek; Jul 8, 2021 at 06:55 AM.
Air inlet screen openings are bigger than the holes thru the evaporator. Debris buildup will compromise the evaporator and the finer stuff comes thru into the cabin. Fiber filter material wrapped around an activated carbon filter sheet will make it like a modern cabin air filter.
I got my factory AC on my 79 going again last fall. New compressor and evaporator. It comfortable enough to ride around in blazing temps, but it does not work nearly as well as my wife's Tahoe for instance. I want icicles hanging off the vents! I'd be curious to know if a Sanden compressor would make much difference. Oh, I did switch to r134. I was told it should run within a couple of degrees of what it would have done with r12.
I got my factory AC on my 79 going again last fall. New compressor and evaporator. It comfortable enough to ride around in blazing temps, but it does not work nearly as well as my wife's Tahoe for instance. I want icicles hanging off the vents! I'd be curious to know if a Sanden compressor would make much difference. Oh, I did switch to r134. I was told it should run within a couple of degrees of what it would have done with r12.
I don’t think so..
1500 rpm hood closed fan on low what is lowest temperature? 34-46f cycles compressor all is well..of course if real hot it won’t cycle..and of course a manual shut off valve helps
Last edited by interpon; Jul 12, 2021 at 07:07 PM.
Heres what I did, Factory A/C system goes down to 42 degrees. May not be what you want but I don't care what anyone says the factory A/C gets very cold when done right.
A/C Question - '79
).. i know many leave off but it sure is nice to have in winter..and defrosting..or that chill in the night windows down..
