worn out rear brakes after 3months

[whutsupdoc]

ok... my 94 Q45a has been running great forever... but this year (must have been all the darn snow)..its dying slow. In march i replaced the rear brakes with bendex semi-metalics... this past weekend what do u think happened????... yep the darn pads on the passenger rear were down to BARE metal (and grooved the hell out of my rotors)....

did i do something incorrect with the replacement of the old pads??? i bascially used a large c-clamp to push back the piston on the caliper and re-installed the pads.... isn't it suppose to be this simple??? HELP??? i don't want these new pads to wear in 2-3 months.

[DAEDALUS]

There's an ongoing thread about bad brakes. Did you remove the shear pins, clean them (and their boots) really well, and then lube properly? Consider it mandatory every time you replace your pads. If you did all that, then something else is very wrong. Bad bearing?

http://www.nicoclub.com/forums...24901

[PalmerWMD]

Shims.

Fred...

[whutsupdoc]

sorry.... which shims are you referring too??

[DAEDALUS]

There are shim pairs between the pads and the calipers/pistons. Each pair consists of a thin metal plate and a soft pad. Mostly their function is to dampen the vibration of the pad and eliminate brake squeal.

[DrewQ45]

Sounds like your caliper is locking up. The caliper opens and closes (braking) by sliding along the pins which must be kept lubricated by high temp grease. If these pins become dry then the brake stays in a semi-applied position. A telling characteristic is uneven brake wear (one pad has much more meat than the other) or the fact that the passenger side wore faster than the driver's.

This happened on my infiniti... the slide pins were so dry that they were no longer smooth and had actually started to accumulate deposits on what should be a slick steel surface. I rubbed them down with steel wool before lubricating them.

Infiniti sells a caliper kit which comes with grease and seals etc.

..Drew...

[szh]

Mu usual dumb questions for the experts.

If a caliper were locking up and causing the pad to drag heavily on the rotor (enough to cause a pad to wear out in 3 months!), wouldn't this be noticeable in driving? Particularly if it were on one side?

I would have expected some "pulling" to the other side - during driving and/or braking. If not, then it is disconcerting to hear that serious car problems can be occurring with no evidence in driveablity! How does one then know when things are going wrong in general till it is too late? It is not possible to check everything on the car, all the time!

Confused ... and concerned!

Z

[DAEDALUS]

Yeah, I would think you could tell the difference, but probably not all the time. Consider a single gradual stop from 60MPH. The pads will wear x amount. If the brakes then began sticking with the same force, the driver could accelerate back up to 60mph and, because the original stop was gradual, perhaps not feel the difference. But by the time he was at 60mph, he's already doubled the brake wear. But the pads will continue to wear while he's crusing, though less and less. Eventually the pads will stop wearing until the brakes are applied again. Thus each stop-and-go cycle could conceivably triple or quadruple (maybe more?) the wear of a single stop without being all that noticeable. The softer the pad, the more wear that would occur while cruising, since a given amount of braking force would cause greater compression of a soft pad relative to a hard pad.

[bodyman240]

i have z32 brakes and the calipers are brand new, would I have to lube the pins in those?

[DAEDALUS]

Definitely. The lubrication will prevent/delay oxidation, wear and scoring on the pins. Aside from the brake pads/rotors I can't think of a single metal-to-metal wear interface that isn't lubricated.

[bodyman240]

would the new calipers come already lubed or is that something you must do on your own. I thought that they would be ready right out of the box.

[Q45tech]

Wrong..............thats why when I true my rotors I clean the brakes up each time probably over kill...........but they are your brakes after all.

Go idea to examine them at least every year...........not the just look with a flashlight method.

Amazing that people ignore them between pad changes.

[bodyman240]

could you explain that process briefly, because for one I have never done it, and I would like to know how.