Thundercat New Front Pads Judder

[MAR5H7]

Hey there

Iv known for a while my front pads needed replacing, as there was little to no friction on the brake and the MOT inspector hinted towards them a few months back.

I also noticed a Juddering feel when I was using the front brake, the more I pulled the more noticeable it became. so I stopped using it until I got the new pads as I thought this would solve it.... I was wrong

I never had a problem when I first purchased the bike but then it just suddenly appeared around 2 months ago

With the new pads, they are sticking to the disc and pulling away is rather a chore on the bike, like it doesnt want to go but then budges through :/

As for the calipers, when removing the old pads, I noticed on each caliper, on one side, the pots were stuck, and to back this up, one of the old pads still had about 1/2 the graphite on it still

Anyone have any ideas/ solutions??? would really love my front brake back smooth and to not put more stress on the engine from pulling away at lights

Thanks
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Ex: CBR 125 R 06', ZXR 400 96' (RIP), Bandit 650 06'
Owned: SRAD 600 97'
Current: YZF Thundercat 600 96'

[Nick 50]

If the pistons are stuck, clean them. If I were you I would strip the calipers, clean them, stick pads back in and then bleed the system.

Have you checked the brake discs? Wheel alignment? (not sure if this would cause the symptoms you mention) Front wheel bearings? Head Stock bearings?

How old are the tyres? Is one side more worn than the other?
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Current Bikes: ZX7r 97 (Black Beauty), VFR400 NC24 (The banana)
Previous Bikes: Aprilia Tuono 03 (The Beast), CBR600f (97)
First bike: A GZ125 Lemon.......

[MAR5H7]

[unitynotsocri...]

uneven pressure on the disc due to sticky calipers cause vibration and can warp discs quicker.On a single disc a seized/sticky piston may be hard to detect when riding but on a twin disc front end..dodgy/seized calipers can cause far more vibration and uneven braking,head bearings have more of a clunk.

Follow Nick50's advice and you'll soon have a much crisper front end...worth the trouble of overhauling the calipers,discs,front wheel bearings and checking the head bearings...then it should be good for another 17k..
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nearly a normal tax paying tosser.......with ferrileness suzi100,cg125,cb125scb100n,cb175,cd100,cj250t,kh250,c15,125 bantam,super 6,rickman gs750,xt500,250rs,dt175,lifan125,dolomite1850,metro,Morris220ld,morrisfg,leyland princess,range rover,corsa,vw camper .now struggling with legs. MORE ORDER = MORE CHAOS

[janner_10]

I rebuilt all my calipers on my last bike. Its not that bad of a job to do, a good mornings work but fairly straight forward.

I would purchase genuine Yamaha seals though if you go for it, a couple on here in the past have have problems with other makes. Also, find a small watch makers type screwdriver, makes a great tool for scraping away the crap behind where the seals sit.
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Yamaha FZS600 (Now gone to heaven) > CBR600F4i (SOLD) > '99 YZF-R1

[Nick 50]

Personally I see the front brake as the most critical mechanism on a bike. Your bike has something wrong which means it wont go, not a big deal. having something wrong which means it wont stop properly .......... that's how I look at it.

Stripping the calipers, cleaning the pistons, fitting new o-rings doesn't take that long like janner has stated.

Not only will you have much better brakes, but you will have the piece of mind knowing that you sorted it and they are spot on.
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Current Bikes: ZX7r 97 (Black Beauty), VFR400 NC24 (The banana)
Previous Bikes: Aprilia Tuono 03 (The Beast), CBR600f (97)
First bike: A GZ125 Lemon.......

[dangerousdave]

i had something similar on my Thunderace - it turned out the front tyre was the culprit.

Although the tread was just about within its limits, the tyre was old and hadn't had the pressure checked regularly. This lead to the tyre developing subtle but visible bulges around the centre of the tread. When the brake was whacked on hard it vibrated like hell !

I'd even bought a set of disks to go on the front as I was convinced the disk was warped, but as soon as the tyre was changed the problem vanished.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[MAR5H7]

[el_oso]

popping the sticky pistons on them blue spot calipers is a bitch!
There really isn't many/any complicated parts to the part of the brakes. It's just the hassle more than anything. If you have patience, it is easy as pie.
pop the piston out > remove seals and replace as necessary > clean the groove where the seal sits with a poking/scraping device > put new seals back in > out the piston back in;
like everyone else has mentioned fairly easy. Just takes a bit of time
The real pain with these brake is the bleeding of an empty system. I had to use a syringe to push the fluid back through the system to get a good hard lever
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Duke 390
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