I knew that pattern was possible as I've come across the X wear pattern says Y about your brakes before. Looks like you should just take a peak at your caliper pins. But those brake pads look so far gone I can't believe they were still on the road.

Tapered Pad Wear: If the friction material is worn in a wedge pattern, horizontally or vertically, it’s a good indication that the pad has not been installed correctly. Worn guide pins and a seized caliper slider on one side of the pad can also cause this. To resolve it, service or replace the caliper hardware, lubricate the sliders and replace the brake pads. This can also happen on dual piston, 4 piston and 6 piston calipers where the internal drillings for pressure equalisation are blocked.

 

But those brake pads look so far gone I can't believe they were still on the road.

Thanks for the reply. I’ll definitely tend to the slide pins and make sure everything is right and working.

Yeah,they are bad. I maintain this vehicle for my daughter and I have some guilt. We purchased this about 5k miles ago and I did all of the rehab work to get it running again. I measured the rear brakes at the time and must have measured the thick portion or maybe I just didn’t measure accurately. I was performing routine maintenance this week and found that the rears measured 1 mm. Fortunately there was never a driving problem, but I could have done a better job at the initial service identifying the pad wear.

 

I go through 2 sets of rear pads for 1 set of front. They could have worn a lot in 5 k in crappy traffic conditions.

 

That amount of taper is totally normal in my experience. Sliding calipers like these are hardly perfect, and the rubber bushings on the guide pins allow some deflection that leads to this sort of thing. I wouldn't be concerned if I were you.

 

Interesting. I haven’t experienced taper like this on my other brake work but appreciate your experience and input.

 

I haven't experienced this tapering either. I replaced the brakes on my S40 a 4-5 months ago and the pads wore down evenly. If there was a taper, then it was minimal.

+1 to inspect the caliper pins, and replace them if necessary. BUT, keep in mind, that for some reason VIDA says to NOT lubricate them, they're supposed to go DRY. That's how mine were, I just cleaned them and put them back.

 

I haven't experienced this tapering either. I replaced the brakes on my S40 a 4-5 months ago and the pads wore down evenly. If there was a taper, then it was minimal.

+1 to inspect the caliper pins, and replace them if necessary. BUT, keep in mind, that for some reason VIDA says to NOT lubricate them, they're supposed to go DRY. That's how mine were, I just cleaned them and put them back.

Are the slides exposed at any point in time as the pads wear?

 

That brake pad wear is caused by the brake pads being installed incorrectly.

On the rear brakes, when rotating and pressing the piston back in the bore, you must align the the notch in the brake piston with the nub on the inner brake pad (the pad with the single nub in the center, rear edge of the pad), otherwise the pad will be cocked and wear like this.

The outer brake pad is the one with the tension clip on the back of it and the 2 nubs will fit between the "fingers" of the brake caliper.

From the picture, it looks like the outer pad was installed at the inner position with the nub riding on the piston and cocked.

 

That makes sense

 

I'm wondering about the correct pad installation. I have Akebono pads (ACT1095) and they're like this:

I installed the pads with the spring on the inner side, to avoid the piston making all the force on the rivets. and installed the other ones in the outer position, with the same idea. the caliper contact surface will be against the flat part of the pad.

Now I'm wondering if I did this wrong or not.

 

Yes, you are correct.
The pad with the pig tail clip on the back goes on the inside/piston side of the caliper. The pad without clip goes on the outside. The second spring that is installed on the outside of the caliper makes that outer pad stay quite and not produce rattle.
If that outer pad is installed on the piston side, it will usually create quite a bit of rattle and the rivets interfere with piston.

Anders

 

After actually looking at my rear brakes, I now see that I was wrong in my post above. As others have noted, the pad with the tension spring is the inner pad. 🥴