Has anyone adjusted the tension on their water pump belt on a cat 3126?

[Richard Good]

I have a Cat 3126 with a rear radiator. The 2 bolts appear to be 1/2" and it looks as though there is a square indent to insert a socket drive to adjust the tensioning plate. My 3/8" drive seemed loose and I need an offset wrench for one bolt. The one I can get a socket does loosen freely. I thought I would see if I can get any feedback before I start in case someone else has tackled this and has any words of wisdom.

[Eric Maclean]

Richard
My 97 Patriot has a side rad which makes it easier not get at but the 3126 is the same the easiest way to make the adjustment is to remove the serpentine belt tensioner which will give you full access to the second bolt on the water pump belt tensioner.
While your there check the bearings in both tensioners for roughness , noise or any movement.also check the serpentine tensioner for full travel movement .
Also look over the hydraulic pump drive coupler for back lash .
You will have to remove the pump bolts and move the pump back far enough to create a gap in order to replace belts if they are needed.


Hope this helps
Eric

[Mike Shumack]

The bolts on my CAT engine (not a 3126) are all metric (i.e. 13mm not 1/2").

[Richard Davis]

Richard
Years ago I was forced to adjust tension on the water pump belt on a 3126 in a campground.  It took 3 trips to parts stores to finally find a 1/2 inch box end wrench with the correct angle offset to get to that bolt.  But, I finally found one and got the job done.  Now I have a few extra 1/2 inch wrenches.
Richard

[Carl Boger]

Tightening that belt is a PIA!  A offset wrench and two people will make it easier. Removing serpentine belt will also give you better access.  Get ready to get under and over the engine and get dirty.  You can see what needs to be done, but you still have to get at it!  Clearance is tight.

[Richard Good]

So, job accomplished without removing anything else. Items needed: a couple of magnetic led flashlights, a 1/2" x 6" socket drive extension, an offset 13mm 12 point wrench, a 13 mm 6 point 3/8" drive socket and 2 ratchets, one 1/2", one 3/8". a shop crawler so I could lay on my back and slide around. I have a rear radiator so this is pretty much only accesible from under the engine.
I was able to insert the 1/2" drive extension in the slot in the adjustment plate without removing the  serpentine belt. I used some pb blaster in advance on the pivot and adjustment bolts. I used the 13 mm socket to loosen the pivot bolt and the 13mm offset wrench to loosen the adjustment slot bolt. I then used the  the 1/2" ratchet to tension the belt whilst simultaneously tightening the adjustment slot bolt. After that I retightened the pivot bolt.

[Eric Maclean]

Good work Richard
 I know that's a tight area to work and takes some patience

Good luck with your next project
Eric