Vibration Noise When Braking Is Applied

[ajaz]

ok guys! the problem I am having is with the abs brakes, when I am braking the brakes seem to work fine, only when the car is coming to a stop 5-0 mph I get a vibration noise at the front of vehicle and also a slight judder on brake pedal! the abs light is not staying on at dash, so no fault showing.. could it be abs speed sensors? if yes how do I test them? what are the possibilities? I have changed the brake pads also I have greased the sliders on the caliper housing because they were seized! also I have changed the caliper dust boot!! but problem has not gone.

[alan333]

I'd guess warped discs. Especially so as the brake sliders were seized. If you're a confident driver try braking hard at a reasonably fast speed and see if you can still feel the vibe. You'll probably also feel it thru the steering wheel. Be careful tho as the brakes could pull you to one side etc, and obviously do it on a quiet road. Don't try it if you're not too confident behind the wheel. The other way to check is to set a screwdriver or something so that it touches the disc and spin the wheel. If the disc touches the screwdriver at some points but not others then the discs are shot.

[ajaz]

i definetly know its not the discs, i think it might be the abs speed sensors on the wheels! any idea how to test each one with a multimeter!

[jimtaxi]

You need to check your disks again, what check made you think they are ok? I have gone through 4 sets of disks mileage now 186000 at the end of their life they displayed the vibration braking at speed and groaning at pull up to lights. Unless you have access to a magnetic base and clock to check runout you cannot check the disks accurately enough, the slider pins are prone to siezing and should be dismantled and regreased every 20000. All the taxi owners I know 10 drivers approx mileages 200000 in 4 years have had no ABS sensor failures or any ABS unit failures at all.

[My first toyota]

From what you've told us Id say its your brake discs too. Maybe you havn't explained yourself properly.

My last car started off with a vibration in the brake pedal, then the steering wheel started vibrating when braking especially when going down hill. Id recommend you get your brake discs checked before spending time and money on other things which are less likely to be the problem.

[ajaz]

the reason I think its not the disks is because on high speed when braking is applied I don't get vibration, also the steering does not shake or vibrate.. also at the time the car is coming to come to a stop,i get this vibration noise and it sounds like the abs has kicked in! but I will have a look at disks or even get them changed then take it from there!

[Wintertton]

ihave some vibration at the pedal when i first press the brake pedal but no noise at all, second application it is as smooth as ever, looked into the brakes and found the off side rear brake had seized and possibly i think the abs is having the wrong message?.

how to change slider pins and grease them? thanks