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1982 C-10 6.5L Diesel Air Compressor


Techventure
08-22-2013, 02:30 PM
I've been working on this truck all summer revamping it from the frame up and I'm at the point of getting the engine going. I had it turning over and it would not start. Bled the injectors and tried again. Cranked over a couple if times and when I tried again the cable to the starter motor heated up.
Took the starter off and did a check and it spins fine.
I read were the next check should be turning the engine by hand. I did this and noticed the serpentine belt would turn on the air compressor pulley clutch, but the compressor would not rotate. Attempted to turn the compressor over by hand and it would not go.

I'm assuming the compressor is seized. Would I be correct?
If this is true how do I remove it? I'm a little afraid of handling air conditioning systems, however with the right directions I would tackle it.
After removal is it easy to repair or should I put another one on?
How do you recharge the system?

Your experience and help would be most appreciated.
I'm working on this truck as retirement project as I'm almost 70, but have worked on vehicles all my adult life due to necessity...........$$$'s were scarce.

Thanks very much.

Schurkey
08-23-2013, 02:49 AM
The belt rolls the A/C pulley just fine, but the compressor itself cannot be turned by hand? Pulley bearing is OK, compressor is seized. If this is the "R4" Radial 4-cylinder style compressor--and it surely is, from my memory of that model year--they were underdesigned junk prone to failure; particularly the early years. They may have gotten better as the design aged. This coming from the company that built an absolutely bullet-proof A6 compressor (Axial 6-cylinder) twenty or thirty years prior to the lightweight R4.

Rebuilding the compressor in-the-field is no longer recommended; I'm not sure it was EVER a good plan with the R4. A person can buy a rebuilt compressor having a reasonable warranty, at any parts store in North America.

Refrigerant work is regulated, purchase of R12 refrigerant requires a compliance certificate--which although remarkably easy to obtain, is still a pain in the ass.

http://www.ase.com/Tests/cfc.aspx

Which means that once you repair the system, you're probably going to have to take the car to a licensed, certified, (EPA-compliant) service center for recharging. If there is any refrigerant still in the system, you'll have to have an EPA-compliant shop reclaim the existing refrigerant before you work on the A/C system.

There is no logic in replacing the compressor on a vehicle that old without also replacing every o-ring in the system, (Do NOT use cheap-junk Chinese O-rings!) and the dessicant pack (which means replacing the accumulator or whatever part houses the dessicant pack.) It's a good idea to also install a fresh orifice tube and screen. I would not do this work without also having the evaporator and condenser flushed and tested by a local radiator shop. You will probably find that the evaporator box is packed half-full of leaves, twigs, and maybe a mouse nest.

Conversion of the system from R12 to 134a is common, but involves it's own complications, starting with requiring different high- and low-side service fittings also available at any parts store. Opinions on the suitability of the existing A/C rubber hoses when used with 134a are mixed. Some say the old hose is fine, others suggest having the rubber hose replaced with "Barrier Hose" specifically marketed as suitable for 134a.

Short story: You better really want the A/C to work, 'cause this is not going to be cheap or easy.

ASJT3
08-23-2013, 01:27 PM
If you're really anxious to get this engine started (and it sounds like you are), you can probably buy an A/C bypass pulley at your local auto parts store. It takes the place of the compressor and is basically a "dummy" pulley. You can set the compressor off to the side (may sure you secure it somehow from flying around the engine compartment, maybe hose clamps) and leave that job for later while you get everything else set up.

Schurkey
08-23-2013, 01:42 PM
If you're really anxious to get this engine started (and it sounds like you are), you can probably buy an A/C bypass pulley at your local auto parts store. It takes the place of the compressor and is basically a "dummy" pulley. You can set the compressor off to the side (may sure you secure it somehow from flying around the engine compartment, maybe hose clamps) and leave that job for later while you get everything else set up.
If the pulley he has spins on the compressor hub, (which is the way I read his description) all he has to do is DISCONNECT THE ELECTRICAL CONNECTOR TO THE CLUTCH.

Cost = Zero.
Labor time = seconds

If the A/C pulley isn't rotating on it's bearing, the bearing probably costs less than the A/C bypass pulley assembly.

ASJT3
08-23-2013, 04:12 PM
If the pulley he has spins on the compressor hub, (which is the way I read his description) all he has to do is DISCONNECT THE ELECTRICAL CONNECTOR TO THE CLUTCH.

Cost = Zero.
Labor time = seconds

If the A/C pulley isn't rotating on it's bearing, the bearing probably costs less than the A/C bypass pulley assembly.


Got it, I read his post as the belt would "slip" over the A/C pulley

webbch
08-24-2013, 12:07 AM
If the compressor is seized, you'll want to pull the orifice tube and check it...after having the system evacuated. If there's a lot of debris, you'll need to flush the lines and especially the condenser. Otherwise, a new compressor won't last long. A/C systems thrive on cleanliness. I kept my '90 on R-12, having picked up a tank of it a few years back. If you decide to convert, you'll definitely need to flush all the lines anyway, as R-134a and mineral oil (used on R-12 systems) are not compatible.

If you plan on doing any work on the A/C, then do yourself a favor and get an A/C gauge set so you can check the low and high side pressures. I suspect the high side needs a 3/16" flare to 1/4" flare adapter fitting if it's like my '90 K2500.

Techventure
08-27-2013, 07:19 PM
Thanks to the 3 of you who provided the useful information.

I decided to check my starter motor before going on with any further A/C checks. I removed the starter and had it growler checked by a shop and found the armature is fine but the coils in the field frame have shorted.

The fellow who checked my starter has a rebuilt starter available for my truck for $90.00(CDN) plus my old starter. Is his price a fair one?
Would it be less costly to replaced the coils in my existing starter frame? If it is less costly, where would you purchase replacement coils?

On to the A/C.

I was at a vintage car/show on Sat. and talked to one of the car owners who had converted his system over from F-12 to R134a and he has had no problem. He told me it was well under $500 (CDN) to have everything done.
Does this sound reasonable or expensive?
If I don't have A/C my wife will not want to ride with me in the truck and I only drive it in the summer and we have been experiencing some very hot and humid weather as is normal here in Southern Ontario, Canada.

I would appreciate any further input>

Thanks.

webbch
08-29-2013, 05:13 PM
Generally, when you convert a system that was designed for R-12 to R-134a, the cooling capability is reduced. There are various ways to address this problem, the most common being to install a parallel-flow condenser (as opposed to the stock serpentine one), which aids in greater heat transfer. However, this requires custom lines, as PF condensers are generally universal, and no drop-in replacements likely exist for your vehicle.

With that said, this particular vehicle is about as good as it gets for a conversion. A relatively small cab to cool combined with a quite large surface area for the condenser makes the conversion pretty reasonable-performing without any of the above nonsense.

To perform the conversion, you're looking at disconnecting all the components, flushing all the lines, installing all new o-rings and adding back the appropriate amount of esther oil, adding r-134a adapter fittings to the service ports (required for proper conversion), and charging it with ~80% of the R-12 capacity (and adding a conversion label). On these vehicles, I frequently hear that going from the stock white orifice tube to a ford blue orifice tube also helps. Finally, you always replace the accumulator after having the system opened up.

Since it sounds like your compressor has seized, flushing everything is already a mandatory step before putting it back together. Pay close attention to the condenser, as you normally get about 75%+ of the debris in there after a compressor failure. On my '90 K2500, I replaced the condenser. I probably could've flushed it OK, but there were quite a few bent fins on it as well, which helped with the decision to replace. Nice thing about esther oil (or POE) is that it's compatible with both R-12 or R-134a, so you could go with either one (but don't mix them :) ).

Sounds like your buddy just had a straight up conversion. Having gotten in there and done this type of work myself, I'd say $500 is pretty reasonable. It's dirt cheap if that figures includes a replacement compressor; otherwise figure on another $200-300 for that.

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