Abs Pulsing

[Nigebob Squarepants]

I recently had all the discs and pads changed, the back were changed one month and the fronts changed 2 months later. I am now experiencing (occasionally) the ABS pulsing through the pedal

especially when braking whilst on slightly rough or potholed roads! (No warning lights)

The guy who did the rear brakes said the “Shims were shot” and would be best to get some new ones!

Could this be the cause or is it something else?

Suggestions welcome… Thanks.

[gjnorthall]

The shims basically help prevent brake squeal - if the shims aren't replaced, a dab of Ceratec on the back of the pads will have the same effect - wouldn't really affect the ABS system. If the ABS kicks in whilst braking and there isn't a genuine reason - it's often due to a loose sensor, a loose/damaged ABS ring on one of the wheels or a bad cable connection at one of the sensors.

[Cyker]

Do they work okay if you e.g. do 30mph and then emergency brake to a stop? (Obv. only test this on a totally empty road!)

My Yaris displayed this behaviour and it turned out the brakes were not clamping properly, so they'd basically slip until a certain point, at which they'd lock up and trigger the ABS.

If I'd done an emergency brake test, I would have found that the car wouldn't actually stop anywhere nearly as quickly as it should, but I only found that out when I needed to stop and instead rear-ended someone :(

Doing the same test on my new brakes, the car will try to throw me through the windscreen and cause the seatbelt to lock up with NO ABS triggering! Which is what it should do! :D

Another possibility is the tyres are shot and have lost grip; This can happen on older tyres where the rubber is hardening, and the tread depth has decreased.

[don21]

I would be looking at the driveshafts for a broken ABS ring.

[Nigebob Squarepants]

Thanks for the suggestions!

Emergency Stops ok

The tyres are in perfect shape, so I think I will check the sensors and cabling,

then the abs rings and take it from there.

Does anyone know if you need “pullers” to get these rings off?

[Nigebob Squarepants]

Good call fellas!

Tis indeed a split ABS Reluctor Ring…

Mr T does not sell it as a separate item and wanted £345 + vat for the driveshaft !!!!!!!!!!!!!!

Another so-called toyota “Specialist” wanted £75 plus vat !!!!!, also said it comes complete on the driveshaft

eBay wants around £9.99, just for the ring

I got it for £2.99 from www.jandrcvjoints.co.uk

Thank God for the Internet…

Just think how the Garages must have been ripping ordinary jo bloggs off all these years… and still do,

friendly Toyota Garage North Wales execpted.

£345 to £2.99 in a few clicks of the mouse and a tel. call.

[gjnorthall]

There are a couple of ways of fitting ABS rings but in either case - clean up the mounting area to bright metal on the CV joint with wire wool before attempting to fit. The better quality rings are made to fine tolerance and will knock into place - use a few drops of Loctite shaft sealing compound around the inside of the ring - this will make the job easier, will ensure the ring is secure and will prevent water and salt getting under the ring. The second method of fitting is to heat the ring up until it's blue, place it on the CV joint and it will shrink to fit as it cools. Ensure the CV joint boot is well protected - it wouldn't be the first time that someone has burnt a hole through a boot by touching it with a hot ABS ring!