Hi, I've got severe juddering when using the front brake. I've had the head race bearings checked and they appear ok. Any suggestions as to the cause?

It is not possible to provide a suggested diagnosis without knowing the YEAR, MAKE, and MODEL of your vehicle.
That being said, the "judder" (vibration) that you feel in your brake pedal may be a warped front rotor or a sticking front brake caliper. The stuck front brake caliper may be caused either by a sticky caliper piston, or by a worn brake line that prevents pressure from releasing from the caliper.

you,my friend,have a bad rotor right out of the box. don't worry it happens all the time. all parts have a one year implied warranty against defects.its the law,so have it changed.

If bearing races are removed, the bearings cannot be reused, they must be replaced.
1. Support motorcycle so front end is off floor and forks are fully extended.
2. Remove right side cover and remove maxi-fuse.
3. Remove headlamp and headlamp bracket.
4. Remove both front brake calipers.
5. Remove front wheel.
6. Remove front fender bracket with front fender.
7. Loosen but do not remove fork tube caps.
8. Loosen all pinch bolts on top and bottom triple clamps and pull fork tubes from triple clamps.
9. Remove brake hose bracket from the bottom of fork stem and bracket.
10. Remove fork stem cap and remove fork stem nut.
11. Lift handlebars from steering head with upper triple clamp attached. Be careful not to pinch or kink control cables.
12. Remove adjusting nut, seal, and upper bearing out of bearing race.
13. Pull fork stem and lower triple clamp from bottom of steering head.

hi.

if you do not have any juddering when you are not braking, then it sounds like you either have a slightly warped disk, or an internal fault in the ABS unit.

the most likely is a warped disk, the warp may not even be visible (my last one wasn't) but can still cause a nasty judder. take the disks off and get them measured properly at machine shop.
if they are ok, then the ABS system will need to be checked by a qualified mechanic with the specialist equipment needed to test the system. the system is NOT user servicable. unfortunately this would not be something you can do yourself.

i would recommend getting this problem sorted out as soon as possible, as any braking system fault carries the risk of brake failure.

hope this helps.

Hi,

Your discs when fitted had a small runout problem, this will after 2 to 5000 miles develope into DTV Disc thickness variation. To cure this inexpensively go to www.discskimmers.com or www.skimmydiscs.co.uk
and get your discs machined on the vehicle which will eliminate your runout problem solving the juddering without replacing the discs etc.

most tyres would have a weight on the rims if they were balanced its very rear they dont, but check the head bearings first,,,but my money is on that new tyer being out of balance

Inner, (Large), wheel bearing has failed. This has caused the grease seal to fail.
Solution is to replace the bearing, and seal.

1.Check the bearing race in the brake rotor. If any pits, scoring, or other evidence of break down is present, the bearing race must be replaced also.

2.Check the outer wheel bearing and bearing race also. The inner bearing receives the most wear, but cleaning, and inspection of both bearings, and races is a standard procedure.

3.Observe the area on the spindle where the grease seal contacts. Insure that the spindle area is of good repair, and no scoring is evident.

The Black residue that you observe is grease mixed with brake dust.

The vehicle must be jacked up in the front, with safety stands placed in the proper area on both sides. Wheel chocks should be used behind the rear tires. The vehicle should be on a flat hard surface.

The wheel/tire is removed, then the brake caliper. The caliper is not removed from the brake hose, but hung from a hanger device, from the frame of the vehicle. (Small rubber tie down strap? Wire clothes hanger?)

Then the dust cap is removed, cotter pin, and spindle nut. Ease the brake rotor out, be ready to catch the outer bearing. Remove the brake rotor.

Rotor laying on two small wood blocks, (2x4's? 4x4?), blocks under rotor face. (Where the brake pads rub against)
Blocks placed so area of grease seal is not resting on them. Rotor is laying on blocks with outside of rotor facing up. (Outside of rotor faces outside of Tahoe)

Take a long punch, and tap out the grease seal from the inside of the rotor. Through the hole where the spindle goes through. Be careful that the punch is resting on the metal ring of the seal, and not the bearing race edge.

Front rotors on a 2 wheel drive means you have to take out bearings and all, it is recomended that you replace the bearings and races because they will have to be removed to turn the rotors might add 30 bucks to the total , you should check around because some rotors are cheap enough to replace instead of turning them. You can re-use the bearings as long as you are careful not to damage the races
Remove the brakes, caliper and caliper braket, remove center dust cap, remove cotterkey and spindel nut, pull rotor off you might need to give it a whack with a deadblow hammer to get it off of the seal in the back, front bearing should fall out in your hand ,with the rotor off gently pry the rear grease seal out (have a new one on hand they damage easy) remove rear bearing. Clean all the grease out of the rotor center so you can see what you are doing, once cleaned with the front of the rotor on the table you should see some notches at the bottom race,this is where you will place your punch to remove the race, flip the rotor over and do the same to remove the other race. Borrow or rent the proper tool to put the races back in, they have to go in straight and you will probably damage the races putting them back in with a punch. When you put it all back together remember to re grease everything. Do not over tighten the spindle nut when putting the rotor back on,tighten it enough to take out any play then tighten it just enough to line up the holes for the cotterkey. Then take it to a mechanic and get the bearing runout checked and set.then put your brakes back on

Did you get the rotors machined to specs or just change the pads.If not machined suggest you get them checked to see wether they should have been.This affects ABS equipped vehicles more severely

1. for drum brakes with sealed hub(all one piece) remove lug nuts and wheel.
2. spray penetrating oil around studs if there is a big phillips head screw visible remove it with impact driver/if not use big ballpeen hammer ,tap on flat of drum near studs(becareful not to hit them) until drum loosens(your creating a shockwave to loosen rust)
3. once drum is off there are 4-bolts coming in from behind backing plate, remove them then hub should be able to be removed w/a little persuation from hammer.

with out sealed hub ,

1. remove wheel
2. remove dust cap,cotterpin,star washer(if equipped) do not re use cotter pin
3. remove nut then washer, wiggle brake drum and front bearing will come out.
4. put nut on shaft tighten 2-3 turns grab drum by sides and pull towards you this should remove drum leaving inner bearing/seal on shaft
5. to replace reverse procedure making sure to pack new bearings w/grease(take drum and use long punch to remove bearing races, use race/seal installer to install new races

with disk brakes

1. remove wheel
2. remove caliper/bracket
3. remove rotor
4. remove 4-bolts from behind,tap old hub out
5. reverse procedure