How To Apply Belt Dressing To Stop Screeching On Cold Starts?

[Wacky Dee]

I had all my belts replaced recently (car's a 34 GTT) and next few days the belt were squealing so i took it to a local mechanic who tightened them and that stopped the noise.

however a couple of weeks later the squealing has resumed on every single cold start .. the belts are pretty damn tight (imo feel a bit TOO tight) and I don't wannt take it to the local mechanic again as the bloke's very young and might decide to tighten them even further as the only solution adn this might damage the bearings etc I'm afraid.

So anyway I got some belt dressing spray which is supposed to make the belts grip better and not squeal ..my question is how do I apply this stuff? do the belts have to come off ? I mean it's like a hairspray can and pretty big so its impossible to reach the belts from under the hood. Also I can't apply the dressing on the entire belts as they can't be turned when the car is off (or can they ??) so I'm kinda stumped .. anyone done it? any tips?

[Fry_33]

To my knowledge the 'belt dressings' are not good for belts. I think they basically chemically soften (melt) the belt rubber so it grips more. These things are only a band aid fix and one application may not fix it or ever for that matter. This isn't the best for the belts either and you can end up with gooey rubber on the pulleys (or anything else it flies off an hits). Typically a squealing belt is the sign of a tension issue.

What sort of belts have been installed? Is it every belt that is squealing or is it already a bearing? Do you have the air con on when you start it up?

Here is some info on Auxiliary Belt Tensioning that may be useful.

R33___Auxiliary_Belt_Tensions.pdf

Edited November 7, 2008 by Fry_33

[Wacky Dee]

nah aircon is not on .. so it's either the fan belt or the other one. What do you mean by 'is it already a bearing' ?

[Wacky Dee]

I'm thinking of getting a tension meter to check the tightness but I can't quite work out from that pdf what value I should be getting .. ??

[Fry_33]

By is it the bearing already I was suggesting it could be a bad bearing but I guess it would be constantly making a noise if that was the case.

The meter will have a Newtons or kg scale on it (maybe both). You basically just reset them and then just press down until it clicks. Then read the tension on the scale. The place you test it is at the locations of the black arrows. Seeing as how the belts are already on and have been ran in you want a tension value within the Adjustment range in Newtons or kg in the {} brackets.

The info I put up is for an R33 but it should be pretty close, maybe even the same.

[leeboi33]

dude i had the exact same problem all i did was tighten my alt belt till it was tight cos it loosens after a lil cos the belt has to settle in so just tighten it and it should be good all u gotta do is undo the bolt and wind the adjuster

[Wacky Dee]

the alternator belt is pretty tight already ..too tight IMO. There's only about 2-3mm flex in it when it should be 8-12mm from what I've read online. I've also found some info online that says it can also squeal if it's too tight

I'll try loosening it up a bit .. will let yous know how I go.

[RB30-POWER]

you just spray it on the belt with the car idling/running, it's that simple.

will quiten them up, usually only needed with old belts that have gone hard to quiten them as a bandaid fix, kind of masks the slipping rather eliminating it from what i can gather, once the lube dries up in a few weeks, you will need to spray more and go around a never ending circle.

what brand are the belts?

i've never had a problem with most brands, but genuine belts can offer some extra peace of mind for a few extra bucks also.

if you are 100% sure they are torqued properly, you might have an accessory load (alternator/water pump etc) or idler bearing that is causing drag due to faulty bearings, but i would double check the belt quality and torque setting first as nine times out of ten this is the problem, especially your decription of cold start only.

there is a fair load on the alternator belt, it has to spin a fully loaded alternator after initial cold start, plus the viscous fan is locked up on the initial cold start until the fluid flow inside and releases it plus the water pump, so it does need to be tight and some crap belts tend to stretch a little, or more so settle in, so it may take a couple of retorque to get it correct.

if it was power steer, it would squeal as you turned the steer wheel when cold. likewise if the aircon is off, no load is on the aircon belt.

so alternator belt deff the one to look at.

Edited November 9, 2008 by RB30-POWER

[(OO)SKYLINE(OO)]

Your belts should not screech, cold or hot start.

What brand of belts did your mechanic install?