Civicnoobie

4 pulleys under our hoods right? How often do they go bad? Are they notorious? I had a loud hissing/squeal from around my POwer steering pump area when (and only when) my AC is on. I lubed the AC pulley and alt pulley with silicon spray (couldnt reach the AC pulley dont know how and not sure either on the idler pulley where it is). The sqeal is 100% gone. But its most likely only temporary. If it comes back im guessing i need new pulleys?

maxtierney

iTrader: (5)

Belts tend to go before pulleys. Belts are normally good for 100k miles or so. Less, for the smaller belts, but this is when most people change these belts. Sad, but true. Proper tension tends to be the major contributor to belt squeal, due to the accessory belts stretching over time. Uneven wear and brittleness are also a factor. Belt dressing helps to keep the belts "moisturized" and prolong the wear rate. Periodic adjustment of the P/S and Alternator will keep optimum tension on these respective belts. If this is a concern for you, you might want to invest in a tensionometer. Specs for your belt are in the manual. If your timing belt squeals, you've got problems. Pull over...

lowlife9

if you hear your timing belt squeal its already to late.

gearbox

iTrader: (95)

the only pulley i would change is the crank pulley when doing the timing belt service. its the only one with wearable rubber parts inside that dampen crank vibration.

Civicnoobie

Im pretty sure its not my timing belt pulley cause i only get the hissing when my AC is on, thats it. And my timing belt is only about 35,000km old.

I dont even know where all these belts are. I was told the best way to test which best it is, is to do the screwdriver tapping trick.

All I know is i had my power steering belt replaced last summer. My A/C compressor was checked last week and they said its running strong.

And is it true that these belts need to be lubed every now and then?

A buddy of mine says it could be the bearing in my AC compressor gone bad and the fact why you should run your AC for 10mins each month in the winter to keep it from acting up.

Is a tensioner the same as a pulley? So the A/C has a belt, pulley AND tensioner?

Civicnoobie

Turns out its the serpetine belt. Apparentl the serpentine, alternator and AC belt are all one belt on our cars. Just two belts we have aside from timig belt. Puting in new belt now. Went napa brand hope thats ok?

pjb3

I am curious what "the screwdriver tapping trick" is.

Belts transmit power, when the AC is off it takes almost no power to turn the AC pulley. When the AC is on the clutch engages and the AC use a lot more power. If the belt is not tight enough it slips and you hear a squeeling sound. If it slips enough it will glaze the belt which will make the belt able to transmit less power and the squeeling gets worse. You can spray lube on the belt to reduce the noise but you are masking a problem instead of fixing it. A belt can be 1 week old and bad if it has been allowed to slip enough to glaze it. I would never lube a belt.

The hard part of replacing a belt is getting the tension right. If the tension is too low the belt slips, if the tension is too high it puts stress on the bearing of the accesories such as AC, PS and alternator. Most places make the tension a little high when they install the belt so that after it stretches it will be correct. Unless you have a tool that measures belt tension, I set the belt to the least tension that does not cause it squeel. If it starts to make noise then I increase the tension small amounts until it stops.

There is not always a seperate tensioner but there is always a way to adjust the tension. For example, if the belt goes around the crank shaft pulley and the alternator the tension can be adjusted by changing the distance between the two pulleys (moving the alternator). If it is a problem to make the alternator moveable then they may add an idler pulley to adjust the tension and this would be the tensioner. This is simply a third pulley that is adjusted to create the tension needed. Idler pulleys are also used to increase the amount of belt contacting the pulley. If a belt runs between two pulleys there should be around 180 degrees of contact, if there were four lets says it would be 90 degrees of contact. An idler pulley can cause the belt to take a different path and increase contact from say 90 to 120 dregrees. The more belt that contacts a pulley the more power it can transmit.

Civicnoobie

I just read somewhere online about using a screwdriver to tap against the belts to see if the sqeal goes away.

My mech pretty much said the same as you, if its not tightened properly itll put extra strain on the alternator. He said its not even worth paying labour to tighten it, might as well just replace it so I did. No more sqeal.

Now for my other problem (rear right tire thread), that is still up in the air but i think im a bit closer to figuring it out.

Also just curious why you would never lube a belt?

pjb3

Belts transmit power by friction. The amount of power that can be transmitted is a function of the area of contact, the tension of the belt and the coefficient of friction between the belt and pulley. A belt dressing can act in two way. If it acts as a lube it will allow the belt to slip without squeeling which will reduce the power transmitted. If it acts by making the belt sticker then it is causing the rubber to break down quicker.