belts

[Trunkster]

I have had a few squeals from what I thought was my alternator belt so I have adjusted it up fully. It has since carried on and after further investigation it appears to be the water pump belt slipping. How do you change the water pump belt on a 1.9 td aaz engine. It has three allen key bolts in the centre of the water pump pulley and four in the bottom pulley. I assumed there was a bolt to slacken it off the same as the alternator but I cant see one! Does that mean I have to undo the three water pulley bolts and simply remove? How do you adjust the tension or don't you? While it is off I will change both belts. Is there any thing else worth changing or needed when I change the two belts?
Thanx

[Wychall]

Hi Andy. As you haven't received a more knowledgeable answer, I'll throw my idea in. The water pump on mine (Audi 5 pot) is mounted on three bolts in elongated holes so that rotating the pump adjusts the belt. Hope this helps.

[max and caddy]

It's not like the Audi setup...if you remove the 3 bolts holding the pulley on you will find a stack of shims between the 2 pulley halfs...move these to the outside of the pulley and the belt will be tighter...don't leave the shims out altogether as most "mechanics" do as then in future a new belt will be to tight and whoever fits it will need l find the rare shims.

I'm 99% sure it's the pump pulley you need to remove but if there is an idler it could be that's where the shims are...I can't picture the setup as mine is a PAS configuration and has no shim stack.

If there are no shims at all but one of the pulley is in 2 peices the belt is worn out and needs replacment...and you need shims!

[California Dreamin]

Sounds right....altering the belt tension by removing or adding shims between the two halves of the pulley was commonly used by VW although I can't be 100% sure this is the method employed here but it sounds likely.
FYI...you have to turn and tighten so the belt isn't pinched but rides 'higher' in the pulley groove as the allen bolts are tightened...it might take several attempts to get the tension right.
Check after the first 'run' as they do have a tendency to slacken quite a bit initially.

Martin

[Trunkster]

Thanx for the replies guys. The front part of the pulley comes off via 3 bolts and the pulley is in two halves. No shims on mine, it is as Martin says. Just squashed between the two halves and you have to keep spinning it to stop it pinching. Very basic really and only a 10 min job.
Thanx again

[Oldiebut goodie]

The shims should be sat on the outside of the pulley ready - unless some bright previous owner ditched them.