New pad installation problem

redridernl

redridernl

Well-known member
I tried to replace my brake lines and pads today. Started with the rear in case there were any problems. The new pads didn't seem to fit, when I finally got them in, they were super tight and the wheel wouldn't turn freely. Took it around the block and it was dragging but applying the brake didn't seem to do anything. Should I not use the oem backing plates with the new pads and would that make enough of a difference?

Thanks
 
The backing plates are integral to the pads. A pad is usually a metal plate at the back with a smaller but thicker piece of braking material glued or riveted to it. Usually the backing plate on the pad directly contacts the caliper piston or caliper body.

Did you remove the brake material and backing plate? They sometimes separate over time. Pics would probably help since I can't quite figure out what you are trying to say.
 
I heard you have to compress the brake caliper in,with a clamp.to allow the new pads to seat to the original setting,could be a problem if they are too tight on the disk.
 
When installing pads (on the rear, and with some front brake designs) there are two primary things you need to be concerned with regarding the caliper. First, the piston must compress properly into the caliper smoothly and there shouldn't be any fluid or wetness under the dustboot. Second thing (which I suspect is your problem) is that the caliper must slide smoothly on it's mount. The piston in the caliper applies pressure to the one pad and the other pad is applied to the rotor by the piston pressure sliding the caliper.

Was the caliper difficult to slide back into place on the pin? Did the pin that the bolt goes through slide easily?

- the above comments are only applicable to sliding calipers where there is a piston(s) only on one side of the caliper
 
Thanks Sircastic.

The caliper, from what I can tell, moves as it should. I think the big problem is that the pads are just too tight against the rotor. From what I've read on 1000rr.net, it's okay to leave the backing plates off so I'm going to give that a try in the morning to see if it's enough to let the wheel spin freely. If I'm still not getting sufficient braking power after that I guess I've got another issue.
 
redridernl said:
Thanks Sircastic.

The caliper, from what I can tell, moves as it should. I think the big problem is that the pads are just too tight against the rotor. From what I've read on 1000rr.net, it's okay to leave the backing plates off so I'm going to give that a try in the morning to see if it's enough to let the wheel spin freely. If I'm still not getting sufficient braking power after that I guess I've got another issue.
Click to expand...

Generally the backing plates you're referring to are anti-rattle or anti-squeal shims. The brakes (depending on the design) should function adequately without them. The reason I suggested the caliper and sliders possibly being the cause is that you indicated that the brakes weren't functioning correctly.

Is the rotor OEM? What brand are the pads? I've had an issue in the past where an off brand aftermarket rotor was thicker than the original and was tight until the pads wore down.
If it's OEM and the pads are aftermarket and not fitting properly I would exchange them for another brand. If they don't fit properly and drag on the rotor you risk overheating the brakes and causing more damage than just pads.
 
The 'backing plates' you're describing sound like shims - you can leave them off but if you start getting a squeal from your rear brakes, well, you know what the culprit is. I don't understand how your pads can be too tight against the rotor when there's no pressure on the brake pedal; you did push the pistons back into the caliper before mounting the pads, correct?
 
sircastic said:
Generally the backing plates you're referring to are anti-rattle or anti-squeal shims. The brakes (depending on the design) should function adequately without them. The reason I suggested the caliper and sliders possibly being the cause is that you indicated that the brakes weren't functioning correctly.

Is the rotor OEM? What brand are the pads? I've had an issue in the past where an off brand aftermarket rotor was thicker than the original and was tight until the pads wore down.
If it's OEM and the pads are aftermarket and not fitting properly I would exchange them for another brand. If they don't fit properly and drag on the rotor you risk overheating the brakes and causing more damage than just pads.
Click to expand...

I should have mentioned that I put the oem pads back in and everything seemed to be normal.

The rotor is oem. I got Carbone Lorraine RX3 for the rear
http://stores.sportbiketrackgear.com/Detail.bok?no=11012

...and Carbone Lorraine XBK5 for the front.
http://stores.sportbiketrackgear.com/Detail.bok?no=927

I didn't buy them locally. I tried a few shops and no one had anything in stock. If removing the backing plates doesn't work or causes squealing I'll order a set of oem pads from Ready Honda.

Scary said:
The 'backing plates' you're describing sound like shims - you can leave them off but if you start getting a squeal from your rear brakes, well, you know what the culprit is. I don't understand how your pads can be too tight against the rotor when there's no pressure on the brake pedal; you did push the pistons back into the caliper before mounting the pads, correct?
Click to expand...

Correct. I cleaned the area around the piston with brake cleaner and pushed it back in.
 
Did you remove the reservoir cap on the master cylinder before you pushed the pistons in? Have you ever topped up the res while the pads wore down, and the fluid level dropped?
 
JohnnyP636 said:
Did you remove the reservoir cap on the master cylinder before you pushed the pistons in? Have you ever topped up the res while the pads wore down, and the fluid level dropped?
Click to expand...

I've never needed to add fluid. The caliper was off the bike when I pushed the piston in.
 
So you took the caliper off, pushed the pistons in, installed new pads (with or without shims), replaced caliper... and now the pads lock on the rotor? Weird. It sounds either like the pads are too thick for your application, the wheel is not centred, or the pistons aren't retracting (which is why the previous poster asked if your reservoir was too full). Post a link to the pads you bought, if you don't mind. And what year/make is your bike?
 
redridernl said:
The rotor is oem. I got Carbone Lorraine RX3 for the rear
http://stores.sportbiketrackgear.com/Detail.bok?no=11012

...and Carbone Lorraine XBK5 for the front.
http://stores.sportbiketrackgear.com/Detail.bok?no=927
Click to expand...

I already posted a link for the pads. The shims/backing plates were on. They don't lock on the rotor but you can really feel it dragging. The piston pushed back smoothly, the reservoir cap was off and it wasn't too full.

The bike is an 08 cbr1000rr. It seems like the pads are just a mm or so too thick.
 
Redrider, I don't think I can offer any more in the way of suggestions... but just out of curiosity, did you ensure that the rear pads were in fact the right pads for your bike? Should be pn# 1174rx3?

Other than that, it seems like you've covered all your bases - the pads fit, no shims, the caliper floats, pistons retract, fluid's good... bizarre. If it were me, I'd bleed the rear brakes for jokes and see if it changes anything :shrug:
 
redridernl said:
I've never needed to add fluid. The caliper was off the bike when I pushed the piston in.
Click to expand...

Ok sometimes people dont open it and dont have enough room in the res for new pads, so it makes the brakes have constant pressure on the rotor even with no lever pressure...

If you are sure the pistons are pushed all the way in, they should be flush with the caliper face. And they are still tight then something is wrong, there should always be some free space with the pistons pushed all the way in and new pads...It could be that the new pads are thicker and not designed to use the backing plates, or it could just be bad tolerance in the manufacturing of the pad and they are too thick...

If you have a pair of vernier calipers, you can measure the width of your caliper slot, the thickness of your new pads, and the thickness of your rotor..Add them up and see if the match allows them to fit properly with some free space
 
JohnnyP636 said:
Ok sometimes people dont open it and dont have enough room in the res for new pads, so it makes the brakes have constant pressure on the rotor even with no lever pressure...

If you are sure the pistons are pushed all the way in, they should be flush with the caliper face. And they are still tight then something is wrong, there should always be some free space with the pistons pushed all the way in and new pads...It could be that the new pads are thicker and not designed to use the backing plates, or it could just be bad tolerance in the manufacturing of the pad and they are too thick...

If you have a pair of vernier calipers, you can measure the width of your caliper slot, the thickness of your new pads, and the thickness of your rotor..Add them up and see if the match allows them to fit properly with some free space
Click to expand...

The piston isn't flush with the caliper. It sticks out a very small amount but it pushed in smoothly up to that point. Like I said, I cleaned them, they were off the bike so there shouldn't have been anything to interfere with the piston. Are they always flush?
 
redridernl said:
The piston isn't flush with the caliper. It sticks out a very small amount but it pushed in smoothly up to that point. Like I said, I cleaned them, they were off the bike so there shouldn't have been anything to interfere with the piston. Are they always flush?
Click to expand...

You tried to save money and bought the wrong pads. Doh! To fix your clusterfak go to the dealer with your year and model and let the dealer determine the pads you are to use. Don't be a hero and go in with part numbers. Let them help you out and figure it out for you.
 
redridernl said:
The piston isn't flush with the caliper. It sticks out a very small amount but it pushed in smoothly up to that point. Like I said, I cleaned them, they were off the bike so there shouldn't have been anything to interfere with the piston. Are they always flush?
Click to expand...

Yes, they should be completely flush.
 
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