Brake Pad Wear Pad squealer: inner or outer pad?

[WalkGood]

2001 LeSabre Custom

I was taught and I've read that the wear tab "squealer" on disc brake pads should be installed as the inner pad. And the wear tab should be on the leading edge of the rotor. Because the inner pad wears more it is better to have the tab on inner position to warn when it got too low.

I bought a PowerStop "kit" of ceramic pads and the rotors. I put the pad with squealer wear tab into the caliper mount bracket, on the inner side with the caliper piston. But the wear tab made contact with the bracket. It was solid contact and would drag on the bracket. The tab is too wide. If I put the pad in the outer side the tab did not contact the bracket. So I called powerstop customer service, got a tech to call me back. He verified that I had the correct pads. Said it would be okay to put the pads on outer position but agreed that they should go on inner position. He could have new pads sent to me but I'd have to wait for them a few days. I asked if I could grind the side of the tab that was contacting the bracket. He said that would be okay and that he has done the same in the past. So I ground the tab a bit on the side.

Anyone ever encounter this problem?

 

[BuickGirlFromMars]

This is just if you need help with the pins to

The brake pad wear sensor should be on the trailing edge of the pad touching the piston
The reason for this is the trailing edge tends to wear more(esp with 1 piston) and the inside pad is more likely to drag than the outside pad, thus, we want to know when that point hit its wear inidicator, so you have warning/time for the whole brake set. Lube them properly, use the right products. Service them every couple of years at most (hardware+lube) the reason those pads had clearance issue is likely because your car has 15 inch wheels?
If Im wrong on that, you have rear disc(16 inch wheels), then its becuase that pad design doesnt match your rotor/caliper but that isnt a big big deal. can you show us the fit problem.

 

[BuickGirlFromMars]

Thats a THICK ass rotor you got there. Wheres it from?

 

[WalkGood]

Thats a THICK ass rotor you got there. Wheres it from?

Must be an "optical delusion" of the pics. The forum made me shrunk the file size. But even the small size looks better on my laptop that after posted to this forum.

You mighta missed it in OP, these are powerstop brand rotors.

Regardless of leading or trailing edge, the tabs are too wide. My 2001 LeSabre Custom has 15 inch wheels with 11" front rotors. I verified the pads are correct for this vehicle. I don't have a pic of the tab scraping the bracket. I did try both pads with tab, it still scraped the bracket whether leading or trailing.

I forget which brand & vehicle, but I've bought pads where all four had the squealer wear tabs.

 

[WalkGood]

Thats a THICK ass rotor you got there. Wheres it from?

Looks normal to me. Marked as minimum 30.7mm, I didn't mike it tho. I can do that for other side since havent done it yet. Will do when it stops raining here in 2 or 3 days. (Don't worry I'm not driving it with half new brakes).

 

[2007LucerneCXL]

Right box, wrong part? Not saying if the pads had a part# on them and confirmed, but did QC in automotive and had seen enough to never assume everyone was having a good day at work on all the parts lol.

As long as you are happy with the fitment that all that counts.

 

[WalkGood]

Right box, wrong part? Not saying if the pads had a part# on them and confirmed, but did QC in automotive and had seen enough to never assume everyone was having a good day at work on all the parts lol.

As long as you are happy with the fitment that all that counts.

There is a part # , date code and some other number on the pad metal plate edge. I read off to the phone tech, he said was proper for my car. The physical comparison/dimensions are all correct versus the old pad. What I think is, the wear tabs are the wrong width. Or the tab mounting hole is not in right spot, skewing it just a bit. Five seconds on bench grinder "fixed" it.

Now I'm puzzled by the leading vs trailing edge for the tab location.

Not that they are correct. But I google searched, watched pro mechanic videos they put the wear tab on outer pad of same gen LeSabres. Also the inner. Read a bunch of web pages say put the tab on inner pad on leading edge. I've seen uneven wear on brake pads, but I don't recall if leading or trailing edge. I cannot dispute putting wear tab sensor on trailing edge. But I'll do it.

 

[2007LucerneCXL]

This is from the Chilton manual, but they also mentioned the calipers had two designs but not sure on what is different between them.

 

[WalkGood]

This is from the Chilton manual, but they also mentioned the calipers had two designs but not sure on what is different between them.
View attachment 39661View attachment 39662

Not clear if 2nd sketch has wear tab on inner or outer position.


The lesabre with 16 inch tires and 12inch rotors would have different size bracket , so perhaps caliper too?

 

[2007LucerneCXL]

Again not sure on what First design VS Second design difference is. As with the tabs they go on the inside at least on my 95 and 07 Buicks, honestly I just matched on how they came off.

 

[BuickGirlFromMars]

Again not sure on what First design VS Second design difference is. As with the tabs they go on the inside at least on my 95 and 07 Buicks, honestly I just matched on how they came off.

1st and 2nd design refers to either size which 15 inch brake cars have a different.... bracket? maybe it was caliper. But The pads are different. or its refers to 97 vs 99 pads.
Or it refers to 99+ pads and 05 pads.
THere are 3 design front pads, gm went throguh. The first design has a pad with tapered ends on the material. Then the 2nd design lost those tapers, then the 05 pads were diffeerent in numerous ways but they were not the whole year. They lost the taper , too, only on 16 inch wheels, but the slot down the center was added, but the 15 inch on lesabre kept the tapers from the 97 park avenue design AND got a slot down center



this is a 15 inch lesabre rotor and pads. the pads have the taper on the edges, which the 16 inch pads do not. I think thats because the size/material being less so the piston is more effective over the pad.
On a 16 inch,

They do not use the taper. So your car should have pads like the top set of pads, which it appears to, does your tab look bigger than that one? quite a bit to me, your theory on the tab is looking strong. but im worried about the pad size now. Can you show us how it fits on the car with the caliper on and the pads against the rotor?

 

[WalkGood]

The new pads I have match up in size to the one's I removed. But yeah, the tabs on my new pads stick out. The ones in your pic (slot and tapered sides) have narrower tabs. I think someone put the wrong tabs on these pads I bought.

I'll get pics when I continue the brakes/rotors replacement. It's been drizzly and pouring rain for last few days. And again Wed.

 

[BuickGirlFromMars]

The new pads I have match up in size to the one's I removed. But yeah, the tabs on my new pads stick out. The ones in your pic (slot and tapered sides) have narrower tabs. I think someone put the wrong tabs on these pads I bought.

I'll get pics when I continue the brakes/rotors replacement. It's been drizzly and pouring rain for last few days. And again Wed.

also after googling more resources, the inboard seems to be universally understood to be the right side, but the trailing/leading is all over the place, which means

I would suggest trying the side which the old pad wore the most, if you can visually tell. leading edge would be the wheel rotating while moving forward, the pad cinches down and contacts first at that point. So it would be the "top" of the pad if your break setup is ahead of the center line of the hub.

But yeah on the sensor thing, good call, regardless of the issue its turning out to be. Because the pads may be dimensionally similar in mounting on the bracket, I still like to see what yours look like when you get the oppoirtunity

 

[WalkGood]

Following up, Life & weather not cooperating with me to get things done.

Here's the drivers side showing the rotor on right and the caliper bracket. Note the rusty gouge line where the pad squealer wear tab was touching the bracket. From the prior brake pads! The old pad's wear tabs were jammed in there. I did not realize.



The wear tabs are not as wide on the older pads as they are on the new pads. But they were still grinding on the caliper bracket. I cleaned up the brackets with wire wheel.





I've got more pics & details to post.

 

[WalkGood]

Here is the "old" pads, showing the wear tab edge where it hits/rubs/gouged the caliper bracket. Yes, there is practically no wear on these old pads. I had replaced the pads when I first acquired the car from a relative about 4 yrs ago. Did not drive the car much , especially during pandemic. It has been our spare car. Car sat for 2 yrs of not driving it. Rotors got rust pits from salty air of my closebto ocean Long Iskand south shore locale. So I decided to get new pads/rotors on it before inspection which would 99% chance of failing the rotors due to rust pits.
Tap on pics to get full view.

 

[WalkGood]

Here you can see the new pad's squealer tab contacting the caliper bracket. And the gouge made by the pad's tab, and debris on the tab edge that was gouged from the bracket. I could feel the contact and resistance while installing the pad which is what made me look carefully at the tab.



Somehow the pics got resequenced here.

 

[WalkGood]

Because the pads may be dimensionally similar in mounting on the bracket, I still like to see what yours look like when you get the oppoirtunity

Just pinging you here to see my update for today. I've got more to post.

 

[WalkGood]

I used a bench grinder and took off some material from the squealer wear tab. Lots of clearance now.





Compared to before

 

[BuickGirlFromMars]

Following up, Life & weather not cooperating with me to get things done.

Here's the drivers side showing the rotor on right and the caliper bracket. Note the rusty gouge line where the pad squealer wear tab was touching the bracket. From the prior brake pads! The old pad's wear tabs were jammed in there. I did not realize.



The wear tabs are not as wide on the older pads as they are on the new pads. But they were still grinding on the caliper bracket. I cleaned up the brackets with wire wheel.

View attachment 40034



I've got more pics & details to post.

What is that red stuff on the caliper piston?

But excellent showing what your situation was and what you did to make those work.
Were both of your slide pins identical or did one have a little recession/rubber piece on the end and the other was a single size through its length?
Did you use a silicone based lube for the grommets/did you use new grommets/rubber dust boots
What did you use for metal contact surfaces and where did you put it ? What metal was the clips used made of?

lastly, how often do you get inspections?

 

[WalkGood]

What is that red stuff on the caliper piston?

But excellent showing what your situation was and what you did to make those work.
Were both of your slide pins identical or did one have a little recession/rubber piece on the end and the other was a single size through its length?
Did you use a silicone based lube for the grommets/did you use new grommets/rubber dust boots
What did you use for metal contact surfaces and where did you put it ? What metal was the clips used made of?

lastly, how often do you get inspections?

Red stuff is Disc Brake Quiet. Yeah, it's kinda redundant with the attached backing plates on the pads. But I've never had a squeal or issue using it anyway. But I've had a squeal long ago, diff car, that this stuff made go away. I'm a creature of habit with things that work.



The slide pins are identical. The bottom one has a long 1.25"(?) rubber tube on the tip. Sometimes it comes out with the pin. But not when cleaned and lubed. Using Sta-lube Synthetic grease.



The rubber boots were in excellent shape, I cleaned and lubed them and also the pins. The metal clips were replaced with new ones with the pads. Caliper bracket (wire brush cleaned) spots where clips contact were lubed with the caliper grease. The contact spots on the pad metal around the ears also lubed.

Safety inspections & emissions testing here are yearly, includes brakes.

Further interesting brake pad info. I found the pads I replaced when I first aquired the car (were in my scrap metal pile). Looks like they were installed with squealer tabs on the outer position. I don't recall that but it's evident from this pic.

.
You can see the squealer tab is wide and would contact the caliper bracket if placed on inner position. I'm beginning to wonder if this caliper/car was spec-ed to have squealer tab positions to be on outer positions.