Uneven brake pad wear on my 2017 Bajaj Avenger 150: Need Advice

These pads were just 2,500+ km old and usually have a life of 18,000 - 20,000 km.

BHPian Warking recently shared this with other enthusiasts.

Hey everyone!

I'm Warking. A long-time reader of Team-BHP, and finally a member of it. I own a 2017 Bajaj Avenger Street 150 BS4. I recently got my bike service in June at the ASC in Gurgaon. The bike was due for its service for the past two months but wasn't able to make time for it.

I took my bike for its annual service. Got the engine oil replaced and both brake pads were nearing their end of life hence got them changed. The rear brake being a drum brake was replaced easily. But when they were trying to remove the front caliper, it wasn't budging open, no matter what. They tried to pry it open with force, tried to open it by trying to open it with a hammer, but it still didn't. They advised getting a new caliper.

They installed a fresh caliper. I verified the part number before installing it. Now for the past month, I've been noticing a weird dust trail on my front disc. Looking at it, I felt something was off with the front brake pad and hence went to the ASC again yesterday.

When they pulled out the caliper, well the top half of the brake pad looked fresh, while the lower half, crossed its half-life. These pads were just 2,500+ km old and usually have a life of 18,000 - 20,000 km.

After looking at the pads, I don't think I have ever seen this type of wear on them. Upon asking why this happened, the SA didn't have an answer and just said that it could be due to dust and water. He suggested getting the pads replaced and I gave them a go-ahead to change new pads. Due to this uneven wear, there was a little uneven wear on the disc as well, which they manually sanded. When they were changing them, I requested them to drive the bike to ensure this isn't happening again.

New pads vs old worn-out pad

After rolling the front wheel a few times and applying the brake so that the wear pattern can be shown on the new pads, the same pattern was discovered, as in the image below.

This caused both the SA and SA's Supervisor to go into blank mode as they failed to understand what caused this. They tried to check the caliper whether was applying even pressure on the pads or not. Nothing wrong was found there.

Due to the closing time of the ASC, they advised us to continue using the old pads as they still have some life left and leave the bike for a detailed inspection as to what this is causing. Now, I don't have my weekends off, neither I've any fixed off days due to my work line, which makes it difficult for me to leave my bike for inspection nor do I've another vehicle to leave this for inspection and use the other for my daily commute.

Has anyone seen this kind of wear pattern in their pads before, and what step should I take next?

Here's what BHPian shancz had to say on the matter:

Welcome to TBHP

Just looking at your pads it's obvious that:

• They're not inserted properly, the entire pad surface should contact the disk rather than 50-60% in your case. Hence that distinct line where the disk ends.
• Since they've changed the pads and then the issue happened I am assuming they've messed something up then. It's obvious that something is pressing the brake pads to your disk continuously which can be the piston / caliper / disk (bent), master cylinder or some issue in the hydraulic line. This is something they've to check and fix.

Easy to test:

1. Rotate your front wheel while on the centre stand and it won't rotate freely.
2. If it does then apply the front brake and then observe it should stop then and won't be rotating freely after that.

If only 2 happen then they have to check the master cylinder area as the pressure isn't getting released. If 1 happens then it could be either, start by checking if one or both pistons aren't sticking out of their normal positions.

I expect this to be the cause but can't say for sure. I also feel that the caliper which they changed wasn't needed as well. Calipers last very long. If they have that lying around then once the issue is resolved, test with that as well. They should return the caliper which they changed if it's true.

A normal worn-out brake pad should look like the one in the video below, right at the start.

Check out more info on the process.

Here's what BHPian sagarpadaki had to say on the matter:

The problem is in the brake disc/rotor. Not the pads. Changing the caliper was totally unnecessary. Looks like a warped rotor.

Bajaj sells complete caliper rebuild kits. Unless the caliper is structurally damaged, it need not be discarded.

Here's what BHPian SS-Traveller had to say on the matter:

This is a case of wrong / mismatched caliper & disc combination. The caliper and pads are wider than the available disc surface, so the outer part of the pads is not engaging with the disc at all, The central mark on the pad is actually where the edge of the disc is.

Get your service centre to fit matching discs, calipers and pads.

Check out BHPian comments for more insights and information.