Strange brake problem

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Winner - POTM March 2018
Hi all,

Hoping you can help. I recently had front pads changed onto old discs (Brembo pads) a few months later I changed discs and then pads. (Brembo HC discs and PBS pads) regular braking has always been fine. Gradually I have started noticing a weird pedal feel however. When I brake quickly and slightly aggressively the feel from the pedal is like something is slipping or catching, but its very specific to the pedal or components attached to it.
This might be ABS kicking in but it feels different to other cars and Id have said its not enough to lock up the wheels.
Could this be the brake master cylinder failing? I have no idea if its ever been replaced but the car is now on 124k.

Thanks in advance!
 
You'd know about it if it was ABS.

Did you bed the pads in when you fitted them? All the faces where the pads slide in the caliper clean?
 
I have the exact same problem at the moment, check my recent thread maybe the same issue! Almost feels like the initial bite is really good then as if the pedal feels funny as if something is blocking it and you can feel it on you’re foot? I’m going for new discs and pads and changing the fluid over to see if that cures it and checking seals etc and generally just making sure everything is cleaned up
 
You'd know about it if it was ABS.

Did you bed the pads in when you fitted them? All the faces where the pads slide in the caliper clean?

They have been bedded in as per PBS recommends. 80/90 down to 20ish x 10 times, calipers cleaned, rear of pads and pins copper greased. Bite, pad feel and power is good, no issue there. I should have said I felt this happened a few times with the Brembo pads. I also had new pins fitted at the same time as the Brembo pads.

I have the exact same problem at the moment, check my recent thread maybe the same issue! Almost feels like the initial bite is really good then as if the pedal feels funny as if something is blocking it and you can feel it on you’re foot? I’m going for new discs and pads and changing the fluid over to see if that cures it and checking seals etc and generally just making sure everything is cleaned up

Does it feel like the pedal is clicking? Thats the most logical way I can put it. I had a thought this morning, if anyone has ever ridden a motorbike or a mountain bike with hydraulic disc brakes, the way I can liken it to is when the caliper seals/ lever seals are on their way out and the movement isnt smooth. I wonder then if its the caliper seals that are a bit old and crusty.