What a frustrating day. I followed my repair manual as best I could. Basically I removed the right side motor mount, belt tension bracket, belts, and then the belt tensioner cover plate and water pump cover plate, both of which are on opposite sides of the timing chain cover. I could see the chain and physically put my hands on the water pump but I couldn't get the tension off of the chain so that I could get the pump out. The book simply says to push the tensioning piston in and place an appropriate size pin in the hole to hold it in. A little to vauge for me. I couldn't get the tension piston to move. I put a screwdriver on the chain guide and was trying to pry between it and the chain cover to force it back into the tensioner and it wouldn't move. After accepting my defeat, and spitting on the floor numerous times, I gave up and put it all back together (5 hrs later). If someone knows the trick, I'll try again. If not, I'll save up the money and have it done. Do we have any experts on the subject.
I did try to find something in the How to section but couldn't find it. If it is there please give me a link to it.

 

you have to remove the cover located to the left of the waterpump almost same sort of cover.. you have to retard the chain 20 degrees counterclockwise and then hold the tensiner in place with a pin this will loosen the chain to allow you to pull out the waterpump... the water pump will come out when you turn the two screws on each side very carefully...
caution i just did mine a few weeks ago its very tedious so what ever you do make sure you dont make the tensioner fall into the engine.. not good. if you have to guess dont do it....

 

CMAX is correct.....you have to turn the crank counterclockwise to slack the chain first before you can push the tensioner in and remove it.

Did my pump over the summer in about 3 hours....

Good luck!

 

I rotated the crank counterclockwise and had some slack in the chain but I still couldn't get the tensioner to relieve pressure. Do I need to remove the tensioner completely and then push the piston in? If I remove the tensioner is there a danger of the chain moving off of the crank gear?

 

No, there is only a danger of pieces of the tensioner or a bolt falling behind the timing cover when you remove the tensioner. You can prevent that from happening by stuffing a rag down into the cavity underneath the tensioner. Be sure to have a magnetic pick up tool handy.

It sounds like there may be something wrong with your tensioner if you can't depress the plunger. Maybe it needs to be replaced, too. They're about $50.

Once you remove the tensioner (or depress it and lock it in the retracted position with a pin), then rotate your crank about 20 degrees in the CCW direction in order to remove chain tension from the water pump. Now you can slip the chain off the pump and remove it.

 

I did this the other day on my other max, and it was terrible, I did all of the above and no cigar, I had to eventually pull the whole timing chain cover off, and then remove the pump from there.... and the first time i attempted this feat on my max, i had giving up, and let a mechanic handle it.