AC system help

[thecantaloupeman]

So I just bought my first truck. It's a 78 C20 Camper special. The AC compressor clutch is bad though. I wanted to know how I go about fixing it, and then how I can make it use r134a refrigerant. Thanks.

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[bucket]

Did the clutch simply fail, or did the compressor lock up and smoke the clutch? These days, it's common practice to just replace the compressor with a reman unit. The cost is often about the same.

 

[yevgenievich]

Reman compressor, clean the system, probably could use new hoses, new o rings, orifice tube, dryer, oil and vacuum/charge

 

[RoryH19]

If the system is original I would replace all components, especially since you are changing to 134a.
New compressor, dryer, condenser, evaporator, orifice tube, O-rings and the rubber lines.
For 134a you will need the high and low side fittings.
After all is installed take the truck to an AC place. Have them evacuate the system and hold vacuum to make sure there aren't any leaks.
Then charge with 134a.
Takes about 80-85% of the R12 amount would originally be.

 

[Red 87]

If the system is original I would replace all components, especially since you are changing to 134a.
New compressor, dryer, condenser, evaporator, orifice tube, O-rings and the rubber lines.
For 134a you will need the high and low side fittings.
After all is installed take the truck to an AC place. Have them evacuate the system and hold vacuum to make sure there aren't any leaks.
Then charge with 134a.
Takes about 80-85% of the R12 amount would originally be.

I had a company do the conversion several years ago, but the AC Delco compressor failed just after a year (only 1-year warranty) and they wouldn't warranty it. So I bought all the components (sans the hoses since they were relatively new) and replaced everything else myself. Took it to a Firestone and had them evacuate and check for leaks and then charge it up. Paid a fraction of what the other company charged me...damn cakeholes.

But now, it's not cooling. So I need to take it in and have Firestone find the issue, and then I'll fix whatever the problem is. It's already starting "Hell season" down here.

 

[RoryH19]

I had a company do the conversion several years ago, but the AC Delco compressor failed just after a year (only 1-year warranty) and they wouldn't warranty it. So I bought all the components (sans the hoses since they were relatively new) and replaced everything else myself. Took it to a Firestone and had them evacuate and check for leaks and then charge it up. Paid a fraction of what the other company charged me...damn cakeholes.

But now, it's not cooling. So I need to take it in and have Firestone find the issue, and then I'll fix whatever the problem is. It's already starting "Hell season" down here.

I do all the work myself too.
For the evacuate and charge I take it to a shop down the road.
Less than $100 so it's not bad at all.

I'm in DFW so I know the feeling of needing a good AC.

BTW, I noticed you still have the bed rails on your R10. Mine are in the attic.

 

[thecantaloupeman]

If the system is original I would replace all components, especially since you are changing to 134a.
New compressor, dryer, condenser, evaporator, orifice tube, O-rings and the rubber lines.
For 134a you will need the high and low side fittings.
After all is installed take the truck to an AC place. Have them evacuate the system and hold vacuum to make sure there aren't any leaks.
Then charge with 134a.
Takes about 80-85% of the R12 amount would originally be.

Why do you recommend getting a whole new system? I am on a pretty low budget so I was hoping I could just replace the clutch and then charge it and be good.

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[yevgenievich]

Compressor should be resealed for r134 use to be reliable if it is already not rated for r134. But will work. On my stealth I used mineral oil with original r12 compressor with good results as well

 

[Red 87]

Why do you recommend getting a whole new system? I am on a pretty low budget so I was hoping I could just replace the clutch and then charge it and be good.

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This explains it pretty well.

http://ricksfreeautorepairadvice.com/convert-auto-r12-system-to-r134a/

 

[CorvairGeek]

We don't know if the OP has an R4 or an A6. I'm guessing an A6 with a V8 Camper Special (unlike my 292 L6). An A6 can run beautifully and quietly as a good conversion. An R4 is on borrowed time when new.

 

[thecantaloupeman]

We don't know if the OP has an R4 or an A6. I'm guessing an A6 with a V8 Camper Special (unlike my 292 L6). An A6 can run beautifully and quietly as a good conversion. An R4 is on borrowed time when new.

Here's my compressor. It looks like maybe I could put a belt on it and be fine, but the part that's in front of the belt attachment is loose or something. Anyways if I did just replace the compressor, what else do I need to do to convert the system to 134a?

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[C10MixMaster]

Here's my compressor. It looks like maybe I could put a belt on it and be fine, but the part that's in front of the belt attachment is loose or something. Anyways if I did just replace the compressor, what else do I need to do to convert the system to 134a?

first you compressor was toast. oil leak and a blown clutch it needed to be replaced.

to convert to r134
must replace the acumulator
remove orifice tube and verify its not plugged with pieces of the compressor.
if you find metal make sure you get it all out or you will have more problems in the future.
orifice tubes are cheep replace it. plus its a different size for 134.
need to get as much of the mineral oil out of the system as possible.
with compressed air you can blow out the evaporator on the truck.
with compressed air you can blow out the the condenser it will clean out better if removed.
the old r12 hoses can be reused if in good condition blow as much oil out of those ass possible to
add new oil to the system ester oil is compatible with the original mineral oil but doesnt work as wel.l GM would not waranty a compressor that had ester oil in it . the other option is pag 150 its a better oil but it not compatible with mineral oil so the cleaner the system the better. some contamination is ok however there is a term called black death associated with mixing pag and mineral oil mostly a problem in fords.
put 2 oz in the evaporator 1 oz in the condenser 2oz in the accumulator 5-6oz in the compressor after the compressor is drained.
reassemble
evacuate the system
charge ~42 oz r134 is recommended (my trucks is making ice with 36oz 3 cans)

 

[thecantaloupeman]

first you compressor was toast. oil leak and a blown clutch it needed to be replaced.

to convert to r134
must replace the acumulator
remove orifice tube and verify its not plugged with pieces of the compressor.
if you find metal make sure you get it all out or you will have more problems in the future.
orifice tubes are cheep replace it. plus its a different size for 134.
need to get as much of the mineral oil out of the system as possible.
with compressed air you can blow out the evaporator on the truck.
with compressed air you can blow out the the condenser it will clean out better if removed.
the old r12 hoses can be reused if in good condition blow as much oil out of those ass possible to
add new oil to the system ester oil is compatible with the original mineral oil but doesnt work as wel.l GM would not waranty a compressor that had ester oil in it . the other option is pag 150 its a better oil but it not compatible with mineral oil so the cleaner the system the better. some contamination is ok however there is a term called black death associated with mixing pag and mineral oil mostly a problem in fords.
put 2 oz in the evaporator 1 oz in the condenser 2oz in the accumulator 5-6oz in the compressor after the compressor is drained.
reassemble
evacuate the system
charge ~42 oz r134 is recommended (my trucks is making ice with 36oz 3 cans)

Well I have a question because I'm confused about how this works. If I want just the defrost and don't care about AC is that possible? I don't care if I'm hot, I just need to be able to see out the windshield if it's winter time or if it's raining and the windscreen fogs. How did old cars defog the windshield without AC?

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[KilgoreTrout]

Well I have a question because I'm confused about how this works. If I want just the defrost and don't care about AC is that possible? I don't care if I'm hot, I just need to be able to see out the windshield if it's winter time or if it's raining and the windscreen fogs. How did old cars defog the windshield without AC?

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I've never used AC to defrost a windshield.

Am I weird?

 

[bucket]

The AC kicks on in Defog mode to reduce humidity. With out functional AC, the Defog will work the same as any truck without AC to begin with.