ABS water pump -How much play is too much play?

[emtee]

Hi Folks,

My 1.8GL is making an intermittant knocking/tapping noise that appears to be coming from the water pump.

If I slacken the alternator bolts and push down on the alternator to loosen the ribbed belt while the engine is running, the noise changes/goes away.

If I push down on the alternator (while the engine is stopped!) and grab hold of the pulley on the water pump as best as I can, I can detect a small amount of play. Would you say that this means that the pump is knackered? I'm kind of thinking that if I can detect play then there's more than is obvious.

It's raining and I don't fancy 3 or 4 hours spent changing the pump only to find that it aint broke.

Cheers for any help or guidance

[emtee]

Looks like I misdiagnosed the problem

Changed the water pump only to be greeted by the same knock at start up.

Decided to triple check the crank pulley bolt and found it to be, lets say, a little on the loose side.

Quick tweak with a socket on a 4ft bar and all seems to be well,touch wood.

Oh well, you live and learn (sometimes...)