On my 79 f 150 400 i have got a squeaky belt. It is tight. It does not make the noise all the time. It does not usually squeal unless i get on it. Sometimes it squeals after i let off the throttle. Will the soap trick fix it properly. I have heard many people say it works while others say it is not a good idea. What is the best way (and safest) to fix it?

 

Which belt is it that squeaks? Is the tension devise for the belt adjusted to it's maximum? If it is as tight as it will get, replace the belt with one that is a little shorter so you will have more tightening adjustment. Could be a worn out and stretched belt. If the adjustment isn't bottomed out, remove the belt from whatever it is driving (alternator, p/s pump, a/c compressor, air pump, etc.) and manually turn the accessory to assess whether the bearing in the shaft of the assessory is worn out and causing excessive drag that makes the belt slip under hard load. Worn and/or dry bearings in idler pulleys and accessories can also make the squeaks associated with belts and add to the frustration when a belt is changed for a new one and the problem still exists afterwards. Belt dressings will temporarily quiet a belt, but it's not a permanent fix. A concentrated spray of WD40 on the belts, one at a time, while goosing the throttle can sometimes help locate which belt is squeaking, providing the fan actually allows you to get it on the belt and not all over you, the engine, the dog, and everything else within fifty square feet!

 

How old are these belts? If they are older than oh.... a year get new ones and get some brake cleaner and clean the pulleys really good before you put them on. If the belts are worn to the point the bottom is touching the pully it's junk, the idea here is for them to just touch the pully on the sides. Oh and don't use soap, you want them to grip not slip.

 

Do not put any form of lubricant on your belts, it ruins them. Do like Phinxter says. If the belt has polished the pulley because it has been slipping for a while it is sometimes necessary to abrade the surface of the pulley with sandpaper or scotchbrite pads. Do NOT do this with the engine on!!! Just work the abrasive around the pulley by hand.

 

Sorry Torque, I wasn't implying that WD40 was a repair. It's an easy way to determine which belt is the one causing the noise. It should be standard practice to replace any belt that has been slipping any amount of time. With multibelt systems, sometimes it's hard to determine just which one is the culprit. And Lord only knows the ages of all the belts underhood. Easier for me to determine if the belt is in need of replacing or do I have to look further into the component that the belt is driving for the cause. It really blows to spend todays prices for new belts, button everything up, and have either: a) still have belt slippage and squealling due to an assessory with a bad bearing or b) completely toast an assessory that could have been repaired with a new bearing had the thing been properly diagnosed. What's the point of puting a twenty dollar belt on only to have it ruined in the first two weeks 'cause of the same undiagnosed problem? Neglecting stuff like hoses and belts eventually leads to the more expensive repairs. Sorry for any confusion or misdirection.

 

Spraying your belts with WD will ruin them tho. I guess if you just wanted to know which one was making noise and intend to replace them all and clean up the pulleys and engine compartment it would be OK...

 

And above all don't use belt dressing. I was at a seminar on belts and drives a few months ago and the question was posed to the Mfg. rep doing the class-- He smiled a big grin and his answer was "use all you want, it doesn't work, and helps me sell more belts." Seems the belt dressing stuff is a carry over from back when they were made of leather eons ago.