Found an easy way to tighten cat 3126 water pump belt…

[bpu699]

My belt was loose, but didn’t need replacement…

Loosened the locking bolt. Pivot bolt would not give, and I did not want to break it,

Went in from the top and used a 2 foot straight pipe and a hammer, to gentle tap the water tensioner mount down. It pivoted on the bolt. The pipe will fit between the serpentine belt and all the other pulleys.

Couple gentle taps, belt was tight, and I tightened the locking bolt. Way easier than trying to use the square drive to tighten it, AND you don’t risk breaking the pivot bolt.

If you do need to replace the belt, do the same in reverse. Just tap the tensioner mount from below to loosen tension on the belt. No need to touch the pivot bolt…

Hope that helps someone.

[Skip426]

The pivot bolt actually protrudes through the timing gear cover ; so you could try spraying the back side with a generous amount of liquid wrench .

My new go to spray is ; CRC Screw Loose , spray on when motor is hot and try to loosen the bolt when cold..

When I purchased my coach (15 years ago ) one of the first things I heard about in the Caterpillar forums was , the two water pump belt tensioner bolts seizing .
I was very careful to remove them and apply a generous amount of anti-seize.

[bpu699]

I tried spraying with wd40… one bolt loosened, the other didn’t. I did spray it from behind also.

I was not brave enough to use in impact (which might have fit between the fan blades…maybe).

But if someone can’t get that pivot bolt loose, the method above is better than pushing your luck and braking or stripping the bolt…

[Skip426]

I was lucky ; as side radiator was one of my " must haves " when I was shopping for a coach .

Removing the serpentine belt and tensioner makes access to the pivot bolt a lot easier .

As I mentioned ; my new go to for stuck bolts is Screw Loose , after years of WD-40 use.
I just found that more often than not WD wasn't working.