Fan belt adjustment on air compressor ISC 8.3

[Ed_95682]

I have a '99 Holiday Rambler with the Cummins ISC 8.3 diesel, with side mount radiator, so direct access to the engine compartment is great. Over the past couple of days, I've been trying to figure out how to loosen the air compressor V-Belt tension in order to replace the belt...it seems fairly straight forward on how you would do this, but still no luck. (I've taken photos, but unfortunately they won't upload to this post)

It appears that the air compressor belt tension, is but together with a threaded bolt attached to the compressor frame and a 18mm nut secures this bolt; which looks like you would tighten or loosen the nut in order to create tension.

I've tried repeatedly to unloosen this nut (sprayed penetrating lubricants, used breaker bar), but it just won't budge. The nut/bolt does not appear to have corrosion and the bolt threads look great.
The nut does not appear to be welded or as part of the frame.

My question: Am I attacking this properly? Is this nut the key to loosening the belt tension or is there something else I should do prior to? Any ideas?

[dons2346]

I think you are referring to the air conditioner compressor?

If so, loosen the two bolts on the base plus the one bolt on the swing arm. Using a large screwdriver, push the compressor to tighten the belt and then tighten the bolt on the swing arm and then the other two.

[Ed_95682]

Thank you for the input. I'll see what other bolts I can loosen. I've taken pictures of the set-up, but unfortunately it doesn't seem like there's a way for me to post them.
I do appreciate the input.

[barnaclebill]

That is the A/C compressor, you have to loosen the 2 pivot points as well as back off the tensioner bolt. I am doing mine tomorrow as I need to replace the serpentine belt behind it. If you don't get it, P/M me for my phone number and I will walk you through it! Bill

[hipower]

Without seeing your actual installation, I would cautiously say that is the tension adjuster.

You should also find a couple of bolts on the lower side of the compressor mounting that are where it pivots when adjusted and generally need to be loosened also.

A word of caution, don't overtighten the belt, the wear on the compressor isn't easy or inexpensive to repair.