Screaching fan belt

[maestro vans]

What causes these fan belts to screach?
My clubman has now decided to do it permanently.I will replace the fan belt
with a new one and tension correctly tomorrow. Do you think it is worth running some emery/sand paper around the water/ crank and alternator pulleys to take the shine off them. Is this causing the belt to slip and screach. Any ideas?

[Blair G]

What causes these fan belts to screach?
My clubman has now decided to do it permanently.I will replace the fan belt
with a new one and tension correctly tomorrow. Do you think it is worth running some emery/sand paper around the water/ crank and alternator pulleys to take the shine off them. Is this causing the belt to slip and screach. Any ideas?

Chances are the rubber belt is worn and needs replaced asap. I wouldnt bother sanding the cogs as the rotation of the belt rolling round them should keep them ok.

Dont make the mistake of spraying WD40 on the belt to stop the screach (as one of our customers did to a timing belt :horror: :nonono: :rage: ) as this eats away at rubber and causes it to snap.

www.blairgmotorsport.co.uk

[H48HPE]

It may not be the fan belt, the water pump squeals when it’s on its last legs,

On mine it used to have a constant whine, which got progressively worse each day of use. At its worse it would do a really loud squeal when the engine started then produce a constant squeaking while running.

It wasn’t difficult to replace, only access was difficult which hindered things somewhat.

Andy

[Jack]

Almost certainly the belt is simply not tight enough. I had a diesel Fiesta with the same problem and I was unable to pull the alternator enough to get the belt tight. I used rubber lubricant spray from Halfords which helped for about 5 minutes.

Eventually I got off my ar*e and got the vehicle over a pit and used a lever to pull the alternator down while tightening the bolts. No more problems. I bet if yours is screeching all the time it'll be quite loose.

[E_T_V]

If a new belt tensioned up correctly doesn't help it'll be likely that either the waterpump or the alternator bearing is on its last legs. Don't do the belt up too tight though as you'll damage the bearings in the waterpump/alternator if you over tighten them. Overtigntening them is difficult on the maestro/montego as they don't have an adjusting bolt, but is easy on some other cars with the adjusting bolt. my rover 214 belt was so tight it killed the alternator and actually seized the engine! :o