Best approach for fixing inop R12 A/C system

[someotherguy]

Its not illegal to purchase r-12, just to manufacture it. Any 609 certified auto a/c tech can procure and install it, and there are also “r-12 replacement” refrigerants that you can use (not sure what’s in them but I had used them in the past after r-12 was pulled from the shelves) that I had success with…just sayin. If you get your compressor running and can do a sat vacuum leak test then that could still be an option for you.

Yeah, I remember some of the replacement R12 products from years ago - Freeze-12 still seems to be available, and it's what we used in a few vehicles back then. It costs a LOT more than R134a does...$198 for a 28oz bottle. I've considered it, briefly, but not entirely sure why I don't feel comfortable with it.

There's other R12 stuff out there but I have to wonder how much of it is bootleg stuff.

Is your system still charged?

No idea but I seriously doubt it. I could be wrong. Since I don't have A/C tools at this time I haven't attempted to find out.

Richard

 

[Erik the Awful]

www.amazon.com/Chemours-Refrigerant-Freon-Self-Sealing-Container/dp/B088HGRJ3Z

 

[someotherguy]

www.amazon.com/Chemours-Refrigerant-Freon-Self-Sealing-Container/dp/B088HGRJ3Z

That's 134 tho.. I sure wish you could find old stock R12 for prices like that.

Richard

 

[L31MaxExpress]

Replace the condenser, I use the 34" wide suburban/tahoe with rear air replacement micro tube parallel flow on all of these trucks. If the orifice is at the condenser outlet, use the Cadillac Yellow 0.062 orifice. It is also called out for on the last of the SUVs like a 1999 Suburban. If the orifice is in-line near the evaporator core I use the Ford Red 0.062". I do not see why adapter brackets would not mount a Sanden to any R4 bracket. Its just a universal bracket that bolts to the R4 bracket pattern and the Sanden ears. I swapped a Sanden in place of a V-belt R4 about 5-6 years ago on an Oldsmobile 350 diesel powered Caprice wagon. My personal preference would be to adapt a ~2003 S10 2.2L V7 compressor as WildBlue19 has done and now has two of them on his Suburban or swap to Vortec brackets to run a HT6 replacement. WildBlue19 could probably make some money having brackets water jetted out to his design and sell them. I will never mess with the unreliable R4 again in anything and the 87 G20 van is proof of that. I will not even touch a system if someone wants to keep the R4. The R4 Scroll is not a good idea if the truck will idle around down in Houston much, it is a lot like the Sanden, inadequate at lower rpm. I get my bulk a/c hose and fittings from Cold Hose and have an inexpensive amazon sourced hydraulic ac hose crimper that works easily and quickly.

Kwik Performance sells a set of adapter brackets that bolt a Vortec 4.3L-5.7L accessory bracket setup directly to a 454 as well. I used a set of those on a 1971 C20 I helped my buddy setup that had a 402 in it. Could use the 10 cylinder upgrade HT6 I have on my 97 Express van that way. 454 vortec accessory brackets are also fairly common to find. You can re-use your TBI power steering pump. Also a good way to be able to run a much more reliable LS Tahoe AD-244 145 amp alternator. The AD244s can put out nearly 100 amps at hot idle and are a far more reliable design overall than anything that came on these trucks.

I would replace the hoses, condenser, accumulator, upgrade to a better compressor setup, at a minimum flush the evaporator core and run the 0.062" orifice. Proven formula for me to get ice cold air even with R134a on a old R4 system. Most of these trucks are missing the accumulator blanket and the suction hose insulation. GM sells the accumulator blanket for the newer Express vans reasonably as an AC Delco part number, it fits all the older accumulators very well.

 

[someotherguy]

Replace the condenser, I use the 34" wide suburban/tahoe with rear air replacement micro tube parallel flow on all of these trucks. If the orifice is at the condenser outlet, use the Cadillac Yellow 0.062 orifice. It is also called out for on the last of the SUVs like a 1999 Suburban. If the orifice is in-line near the evaporator core I use the Ford Red 0.062". I do not see why adapter brackets would not mount a Sanden to any R4 bracket. Its just a universal bracket that bolts to the R4 bracket pattern and the Sanden ears. I swapped a Sanden in place of a V-belt R4 about 5-6 years ago on an Oldsmobile 350 diesel powered Caprice wagon. My personal preference would be to adapt a ~2003 S10 2.2L V7 compressor as WildBlue19 has done and now has two of them on his Suburban or swap to Vortec brackets to run a HT6 replacement. WildBlue19 could probably make some money having brackets water jetted out to his design and sell them. I will never mess with the unreliable R4 again in anything and the 87 G20 van is proof of that. I will not even touch a system if someone wants to keep the R4. The R4 Scroll is not a good idea if the truck will idle around down in Houston much, it is a lot like the Sanden, inadequate at lower rpm. I get my bulk a/c hose and fittings from Cold Hose and have an inexpensive amazon sourced hydraulic ac hose crimper that works easily and quickly.

Kwik Performance sells a set of adapter brackets that bolt a Vortec 4.3L-5.7L accessory bracket setup directly to a 454 as well. I used a set of those on a 1971 C20 I helped my buddy setup that had a 402 in it. Could use the 10 cylinder upgrade HT6 I have on my 97 Express van that way. 454 vortec accessory brackets are also fairly common to find. You can re-use your TBI power steering pump. Also a good way to be able to run a much more reliable LS Tahoe AD-244 145 amp alternator. The AD244s can put out nearly 100 amps at hot idle and are a far more reliable design overall than anything that came on these trucks.

I would replace the hoses, condenser, accumulator, upgrade to a better compressor setup, at a minimum flush the evaporator core and run the 0.062" orifice. Proven formula for me to get ice cold air even with R134a on a old R4 system. Most of these trucks are missing the accumulator blanket and the suction hose insulation. GM sells the accumulator blanket for the newer Express vans reasonably as an AC Delco part number, it fits all the older accumulators very well.

Thanks, that's pretty much the whole kitchen sink approach and probably more than I'm wanting to do just yet. It *should* be easy to cool this truck, being a regular cab, without going crazy on a full system upgrade..

I'm leaning more towards seeing what's salvageable from the current setup. If I can manage to either scab some wires temporarily onto my broken clutch, or use a clutch from a cheap junked compressor (found a couple semi-local), and see if my compressor is any good. If it is, next step would be see if the system will hold vacuum, then decide do I want to spend a fortune on R12 replacement, or go ahead and convert to R134a. Either way I'm spending money, but the R12 replacement seems less wise as once the system decides to leak or something goes bad, I'll be spending that money again, or spending it on R134a conversion the next time around.

Richard

 

[jd33173]

Get the A/C system running with the bare minimum of parts first: compressor, conversion fittings, and a recharge.
If it operates and theres no additional leaks found, then you can go further, tear down and replace the accumulator, orifice tube and perform a flush.
There's no sense in loading up the parts cannon if it has a wiring problem, or another blown up component.
By the way, the high pressure cut-off switch should be on the new compressor. No new wiring needed.

This is truth. It will show you all the special places where its bad by promptly commiting seppuku on whatever the hottest available day after you fix it. Rinse and repeat. Adult beverages and language will be required.

 

[Wildblue19]

@L31MaxExpress is the guru. He's got hundreds of posts on here about AC optimization in our trucks. I'm in the do it right the first time camp - inevitably a patched up old system will crap out right when you need it most.