thrashingcows

I finally decided to swap out my lower A/C and water outlet bracket. I am going to be finishing up my A/C retrofit soon and needed to get that old C171 A/C compressor out of the way, and install my new Sanden A/C compressor.

So I picked up a used lower bracket form a 96 12V motor. Cleaned it all up and then bought a rebuilt Sanden A/C compressor from these guys.....

http://www.acpartshouse.com/

Here is the bracket and new compressor...

thrashingcows

Started by draining the fluid from the rad...Those drain valve location sucks so I use an old rad hose to catch the coolant and re-direct it into the pail. Works like a hot ****!!

Then removed the belt and the Alternator, then the belt tensioner. Here's what the old set-up looked like.





Move the lower rad hose and unbolt he old C171 compressor. There are 4 bolts on the bottom and one on the top. Then wiggle and jiggle the old compressor out. Then remove the old water/ A/C bracket. There are three 13mm bolts around the water outlet, 2 short and one long, and three 18mm bolts down low behind the old compressor location.

Here's the old bracket beside the new one.



Think it weighs 4 lbs less....

thrashingcows

Then install the new bracket. I asked a bit ago about a gasket or O-ring for the lower water outlet on the block but nobody seemed to know for sure. Well it turns out to be a big O-ring. I didn't have new O-ring so I left the old one in place and put a thin coat of RTV over the matting surfaces and bolted things up.

The only thing I found was that one of the 3 bolts that go around the water outlet is too long. The old bracket had a 3/8 raised location for one of the bolts and the new bracket does not. So I had to rummage through my tins of misc bolts to find one that would work.

I didn't have the factory bolts to hold the compressor to the bracket, so I bought four 4" x 5/16 grade 5 bolts, with washers. Don't think the threads are standard thread since they were a little tight going in. Make sire you put the bolts into the compressor before you try and install it, or else you won't be able to get them in.

Here's the new bracket and A/C compressor installed....





Not a bad job...other then the pouring rain today.... Got everything back together and fired it up....no problems with belts length or anything.

So for all you Non-IC guys with bad compressors, here's your fix. Though you will now need to get new lower hoses made up, but since I'm doing the complete retrofit I will be making all my own anyways.

Rampage1967

I believe that the Cummins is all metric which would mean those are metric bolts.
I have found that 5/16 will screw on to that particular size with the results you mention. (8mm i think)
The threads will be off just enough to make them tight.

Jim Lane

How are they diffrent, size or length?

Jim

jimbo486

X2. I can't see the back of the compressor where the lines bolt on but are the fittings different also?

When did you ask about the water inlet seal? I must not have caught it but I was about to ask what condition the original was in and then suggest a replacement. Had I caught that particular post, I would have given you the Cummins P/N for it. Of course, it's too late now but the P/N is 3906697 - $1.56.

thrashingcows

You know after I your comments it got me to thinking....you might be right the original lines might bolt right up. I'm going to dig out my old ones and see. Not that I'm going to use them, but for reference for others who might do this upgrade.

jimbo486

I have a set of i/c a/c lines. I'll go take a peek at them and snap a picture really quick.

Jim Lane

Jimbo
Thanks, I am replacing my C-171 compressor right now but I want to replace it using the intercooled SD709 soon, where is a good place to find the bracket?

As far as the lines I could probably make 2 stubs to adapt the compressor to the existing lines using barrier hose and bead-lock fittings.

Do you happen to have the factory specs on the C-171 compressor?

Jim

jimbo486

Unfortunately, they're nowhere near the same style fitting.

jimbo486

Jim, I don't have any specs for the C-171 compressor. I assume the C-171 is the compressor used on the non i/c motors?? You could get the bracket (aka water inlet connection) at Cummins. I don't foresee it costing too much. Use ESN: 44609750 (that's intercooled).

Jim Lane

Anybody know how much oil that I need to replace?

New Compressor = oz.
Full system = oz.

Thanks Jim

maybe368

The fsm that I have says 44 oz max., but someone found recently that it is 42 for diesels, of course that is for a stock system...Mark

jimbo486

I do know that, with R-134a, you do not need to charge the system with as much as you would with R-12 due to higher pressures seen with R-134a and I believe our systems running R-12 are charged to 2.2 lbs (?).

Jim Lane

Sorry I didn't make it clear,
I am replacing my compressor and I need to add OIL to the new compressor.

Also I am going to flush out the system and I need to replace the oil for the components.

I am using 3.0 lbs. R-12

I will also drain the old compressor and check it but I wanted to make sure on the amount.
Jim