Strange brake wear

Sorry for the long winded post here but I am trying to understand something here and it sounds like there are a lot of knowledgeable folks that visit this section.

My wife was complaining about a noise when she applied the brakes on her Venture. She said it was not a high pitched squeal (wear indicators). I simply bought new pads and shoes and figured I would pull the wheels on the weekend to have a look.

I drove her car down the street and immediately recognized the sound of metal on metal. I went and picked up a new pair of rotors too.

When I pulled off the old parts this is what I saw:

Front Passenger – Metal on metal. The bottom of the pad (trailing edge) was metal on metal whereas the leading edge still had about 1/16” remaining.

Front Driver – Normal wear. Still had some pad left but not much.

Driver rear – Normal wear

Passenger rear – Very minimal wear.

The rears are the factory installed shoes and the fronts are now on the 4th set of pads and there is about 100000 miles on the vehicle.

Obviously I have a lot of questions about what happened so here they are:
1) Could the passenger rear not be self adjusting due to the adjustment wheel being stuck? I remember while the vehicle was under warranty that the dealer “cleaned” the rears. Perhaps they just removed the drums and sprayed brake clean. If so this could have removed the lubrication of the adjustment wheel (although they should know better).
2) Could the presumably not working RR have caused the RF to wear faster than the LF due to the rear not doing anything and causing the front to do all of the work (in lieu of the normal 90% or so)?
3) What could cause the Front Right to wear more on the trailing edge? Is it because it is actually fractionally hotter due to the rotor already being in contact by the time it reaches the trailing edge?
4) Why did she not hear the wear indicators? At first I though it might be due to the uneven wear and thus the indicator never made contact but after looking more closely I doubt the wear indicator would make contact before the fronts were completely worn. It is possible that she did not notice the noise but I doubt it. From what I think I remember is that the wear indicators make a noise when the brakes are lightly applied. If this is true then is the pad expected to rotate slightly (due to the rotor rotation such that the indicator makes contact and then the pad straightens out as more force is applied)?

Just for the record I replaced the pads and rotors about 2 years ago and I put on good quality Canadian made pads and rotors. These pads cost about $40 Canadian so they were not cheap. These pads are not remanufactured either as there is no casting charge.

When I replaced them I did not contaminate the surfaces in anyway and I used a can or 2 of brake clean to clean the new rotors.

I would love to hear some opinions so feel free to comment.

Often uneven brake wear from side to side is due to sticking calipers.
They stick in 2 different ways.

1. The caliper piston no longer retracts properly in the bore when you release the pedal. This allows the pad to rub excessively on the rotor causing drag, decreased fuel economy and excess wear. Often, one side sticks worse than the other.
This is usually caused by moisture - contaminated brake fluid allowing the caliper to rust internally.

2. The caliper does not slide freely on the guide pins and/or the mounting pads on the steering knuckle, due to external rust, dirt etc. This also causes excess (and often, uneven) wear.

IMO your worn side was sticking more than the other side. But both sides may be deficient, causing excess wear.

A good quality brake job always includes new calipers (both sides!) and hardware (guide pins, etc.) to prevent problems like yours. Sure many people risk reusing the old calipers, but it's a gamble. Personally, I have had trouble with sticking calipers about 25% of the time when I've reused the old calipers.

Also, when installing, all rust must be brushed off the caliper mounting pads and a high temp anti - seize or Sili Glide applied to the calipers slide pins and mounting pads.

When new calipers are installed, flush out all the old fluid from the lines to get rid of any contaminated fluid, and remember to bleed the brakes.

Finally, it's impossible to compare front and rear brake wear, since they do different jobs, have different loads and are a fundamentally different design. It's common for cars, especially nose-heavy front wheel drives to wear out front brakes much faster than the drums. So long as the rear brakes function properly, do not worry about their relative lack of wear.

As for the wear indicators, cheaper pads sometimes do not have them. Canadian tire pads, even the good ones are IMO cheaper. This does not mean 'bad' but it means they may not have all the bells and whistles. I have found Canadian Tire carries several different grades of pads for each car. Wear indicators are available on only certain pads and you have to ask for them

Sometimes the parts guy was selling skateboards the previous week and knows squat about parts, and will not ask you if you need them. I always have a good look at Canadian Tire's parts counter screen to see the options available. I never go by what the parts guy says.

Thanks for all of you thoughts.

I would never take the advice of a Canadian Tire clerk nor do I recall any part of my post where I indicated that I had. I did buy the pads and Rotor there. The pads and the rotor was the premium Monroe.Wagner brand and I specifically asked for them. I admit they are not the best available anywhere but they are certainly quality products. The rotor is American. BTW I had said that we DID HAVE wear indicators but they never made a noise. (you must have misread my post).

My concern for the wear was not the difference between the backs and the fronts, I expect the fronts will wear faster. I was more concerned with the wear between lefts and rights on both sets of wheels.

Although I do not doubt that new calipers are the best way to go I don't believe that it is very commonly done. The pads came with new pad retainers. New guide pins would have been a good idea.

You have given me a lot to think about.

Iv never known it to by common practice to replace calipers when doing pads as well.
Certianly on drum brakes you always replace the salve cylinder, but with discs usualy the caliper will function through several sets of pads before a rebuild is needed, assuming the rest of system is kept in good order.

Iv never known it to by common practice to replace calipers when doing pads as well.
Certianly on drum brakes you always replace the salve cylinder, but with discs usualy the caliper will function through several sets of pads before a rebuild is needed, assuming the rest of system is kept in good order.
As I said, a 'good quality' brake job uses new calipers, to avoid problems. Usually, but not always, you can get away with reusing the old calipers; I have done so often, and, by doing so, I have learned the true value of using new calipers whenever reasonably possible.

If the brake fluid is old and contaminated by moisture, the inside of the bore may rust. When you push the piston caliper back into the caliper, the piston and seal will rub over this rusty bit, causing sticking and/or leaks.

Of course, if your fluid is good and clean, you should not have rust and you should not have problems reusing the calipers. But it is a supreme irritation to do a brake job and reuse the calipers just to find they stick, drag, brake and/or wear unevenly. Then you must do the job all over again. IMO its better to do the best possible job the first time.

Since rebuilt calipers are pretty cheap for most domestic cars, especially on the front, I put in new calipers if I am unsure of their age/condition.

some cars have X patern master cylinders.....

what car is it?

Since rebuilt calipers are pretty cheap for most domestic cars, especially on the front, I put in new calipers if I am unsure of their age/condition.


Heres the differnce, I used to work on cars where a set of calipers came with a 4 figure, or even 5 figure price tag, or are simply unavliable any more.
If its my own car, then I have a pretty good idea of what condition things are in, like wise with cars that belonged to regular customers, they might go through a set of pads ever year, replacing calipers at that interval would be very expensive.
However, on cars that were older (which I did a lot of work on) or looked badly maintianed then it was common to at least pull the piston out and check and caliper bore and piston for pitting.
Depending on the car then new calipers would be fitted, or as was often the case just a rebuild kit used, new seals, over sized pistons and rebore the caliper.

some cars have X patern master cylinders.....

what car is it?

It is a 99 Venture.

Heres the differnce, I used to work on cars where a set of calipers came with a 4 figure, or even 5 figure price tag, or are simply unavliable any more.
If its my own car, then I have a pretty good idea of what condition things are in, like wise with cars that belonged to regular customers, they might go through a set of pads ever year, replacing calipers at that interval would be very expensive.
However, on cars that were older (which I did a lot of work on) or looked badly maintianed then it was common to at least pull the piston out and check and caliper bore and piston for pitting.
Depending on the car then new calipers would be fitted, or as was often the case just a rebuild kit used, new seals, over sized pistons and rebore the caliper.
Uh, okay, I was not addressing such high dollar cars here in this thread.

My comments, as I qualified them, were specifically for brake repair on American domestic cars, (like the one in this thread). They have very affordable calipers in front (at my local parts emporium, $15 after core charge) , so reusing them is not worth the hassle.

Obviously, an educated judgement or inspection must be made whan prices get a bit expensive.

I've had expensive calipers and cheap ones. My '77 Lincoln has $18 calipers up front and $200 ones in back. Guess which ones get changed more often? Ditto for my BMW and Supra. :)

Uh, okay, I was not addressing such high dollar cars here in this thread.

My comments, as I qualified them, were specifically for brake repair on American domestic cars, (like the one in this thread). They have very affordable calipers in front (at my local parts emporium, $15 after core charge) , so reusing them is not worth the hassle.


Where exactly in Ontario are you getting calipers for a Venture for $15?