Bends brake disc

[ytre]

Ive recently had to change the front wheel bearing on my Toyota. About 8 weeks later i noticed the steering wheel shutter when i braked. it gradually got worse and when i investigated the brake disc had warped.

I thought i may have bent the hub or flange when pressing the bearing out so i fitted another hub with new bearing and flange and a new brake disc. 8 weeks later and the same thing is happening

I took the wheel off yesterday and all looks fine, brake caliper is free as are the gliders, with car in gear and the disc spinning all looks to be running fine but something is not right and i welcome your opinion on the matter.

Could the alloy wheel be bent though i cant notice anything when its spinning.

 

[s410man]

to check if the alloy is bent put it on the car and set up a peice of wood or metal etc so it is about 3mm away from the alloy part of the wheel not the tyre then spin the wheel and see if the gap gets bigger or smaller but if this is the case the steering will probably shuddder all the time

try swapping wheels front to back

thanks

 

[George641]

Check the rear brakes. Our load sensing valve had failed so the back brakes wernt doing anything. So the front brakes are put under more stress than designed for and give the same symptoms as warped front discs. Perhaps the extra work they do does warp them. Quick and easy to check. Just take it to a friendly mot place to check em. We went through 3 lots of discs getting to the root of this problem. Kept blaming the discs until took the rear drums off and absolutely no dust in there.

 

[ytre]

to check if the alloy is bent put it on the car and set up a peice of wood or metal etc so it is about 3mm away from the alloy part of the wheel not the tyre then spin the wheel and see if the gap gets bigger or smaller but if this is the case the steering will probably shuddder all the time

try swapping wheels front to back

thanks

checked the alloy and there doesnt look to be a twist in it also checked the rear brakes and plenty of dust and with someone holding the foot pedal down they seem to be holding well. I just know its one of these things which wont be easily diagnosed

 

[grandads_shed]

u sure one of the drums are not oval shaped in stead of being round ??

 

[George641]

Ours stopped if you tried turning it with your hands. However thats not comparable with the force required to stop the van. Goodluck

 

[knoba]

The simplest test, for ovalled drums, is to raise the rear wheels, apply the handbrake until it just starts binding the shoes on the drums. Turn each wheel by hand. If there is any ovaling in the drums, you will feel it here.

• Does your vehicle have discs, drums or combo's on the rear, ytre?
• Did you pack the new front wheel bearings, properly, with grease?
• Did you re-check the front wheel bearing hub nut adjustment after running them in?

Personally, I would be inclined to look closer to home; cheap discs (too soft) and cheap pads (too hard)? Where did you source your discs & pads from?

Things are not what they once were; a few years ago, I put new rear shoes & 2 new rear cylinders on my van; branded "patent parts" from a motor factor. One of the new cylinders leaked after a month. So... I replaced them with another set of new shoes & another new cylinder, then the other side leaked 2 months later... Fuming with myself, I bought two new cylinders direct from Ford dealer... they've been fine ever since (2-3 years)! Worked out cheaper, in the end, to go to main dealer. I won't buy critical machined parts from a motor factors any-more.

 

[ytre]

Hi Knoba
Ive discs on the front and drums on the rear, bearing is a sealed one and ive checked the hub nut and its still at the specified torque ref the haynes manual. i bought the discs and pads from a motor factor, think 'i'll scource news pads from dealer and get a disc too from the same. im not hopeful though but i'll try anything.

 

[knoba]

Not an automatic is it?

 

[ytre]

no its manual

 

[rikrobson]

When was the Brake fluid last changed? It will absorb water over time and go from a golden honey colour to an olive oil green colour. The boiling point of the fluid is reduced with water absorption. when the brakes are applied the generate heat and this can boil the fluid making juddering worse. Don't forget that this often gets overlooked and sometimes the fluid can be as old as the car!! It's recommended to change it every 2 years.

 

[ytre]

The fluid was changed about 14 months ago, new brake pipes were installed for MOT

 

[hotrodder]

Read this... http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml#

I thought i may have bent the hub or flange when pressing the bearing out so i fitted another hub with new bearing and flange and a new brake disc. 8 weeks later and the same thing is happening

i bought the discs and pads from a motor factor, think 'i'll scource news pads from dealer and get a disc too from the same. im not hopeful though but i'll try anything.

Did you check the runout of the new discs i.e. a bit of grit or a burr on the hub/disc mounting face that got overlooked could result in runout which can cause disc thickness variation aka 'warped' discs. Any chance you've used the new brakes hard (say leaving a motorway) before they were bedded in and immediately ended up sat in traffic with your foot on the brake i.e. the reason Knoba asked if the car is an auto

 

[Robotstar5]

That link made interesting reading Hotrodder

 

[the snooper]

not all correct though (the part in bold) brakes have had warning system in place for years letting you know when pads are low, the float in the reservoir is to alert you to the fact you are / could be losing fluid somewhere resulting in brake failure.

MYTH # 6 - The brake fluid reservoir should be topped up during routine service.
In most modern passenger cars, the brake fluid reservoir is designed with a specific volume and is equipped with an internal float. The volume corresponds to the amount of fluid that will be displaced when the pads have worn to the point of replacement plus a generous reserve. When the replacement point is reached, the descending float completes an electrical circuit and a light appears on the dash warning the driver that the pads should be replaced.If the brake fluid is topped up the first warning of warn out pads will be the screech of steel backing plate against iron disc. This will be both annoying and expensive

 

[eil]

Have you put new tyres on as well by any chance.

 

[knoba]

ytre
Could the alloy wheel be bent

Yes it is possible... Is there any cause why you would ask?

A few more questions...

1. Are you the only person that uses the vehicle, ytre?
2. You don't ride the brake do you, ie. resting your foot on the brake pedal while driving (I'm just asking...)?
3. After the first wheel bearing change; how did you discover the brake disc was warped?
4. Any evidence that the tracking is out (tyres scrubbing on one edge)?
5. Any minor / major accidents or minor / major work done to the front-end in the last 12 months?
6. How many miles a year does the vehicle do?
7. What's your driving style (maniac / careful)?
8. What sort of travel is the vehicle used for (motorway / local)?
9. Do you think Carol Vorderman is still attractive for her age?
10. With the wheel off; does / did the new disc replacement spin freely, between the pads, without any obvious sideways movement?
11. Why did you replace the wheel bearing in the first place? ...& what caused it to fail?
12. You replaced the front wheel bearing on one side only?
13. Was the other side (disc & bearing) still ok?
14. Where did you get the new wheel bearing & hub from?
15. What equipment did you use to press out, & press in, the bearings?
16. Full make, model & year of car?

 

[brightspark]

Yes it is possible... Is there any cause why you would ask?

A few more questions...

1. Are you the only person that uses the vehicle, ytre?
2. You don't ride the brake do you, ie. resting your foot on the brake pedal while driving (I'm just asking...)?
3. After the first wheel bearing change; how did you discover the brake disc was warped?
4. Any evidence that the tracking is out (tyres scrubbing on one edge)?
5. Any minor / major accidents or minor / major work done to the front-end in the last 12 months?
6. How many miles a year does the vehicle do?
7. What's your driving style (maniac / careful)?
8. What sort of travel is the vehicle used for (motorway / local)?
9. Do you think Carol Vorderman is still attractive for her age?
10. With the wheel off; does / did the new disc replacement spin freely, between the pads, without any obvious sideways movement?
11. Why did you replace the wheel bearing in the first place? ...& what caused it to fail?
12. You replaced the front wheel bearing on one side only?
13. Was the other side (disc & bearing) still ok?
14. Where did you get the new wheel bearing & hub from?
15. What equipment did you use to press out, & press in, the bearings?
16. Full make, model & year of car?

the spanish inquisition

 

[knoba]

...just want to cover all the bases...

 

[hotrodder]

not all correct though (the part in bold) brakes have had warning system in place for years letting you know when pads are low, the float in the reservoir is to alert you to the fact you are / could be losing fluid somewhere resulting in brake failure.

That article is probably from one Carroll Smiths' books as he passed on in 2003. The word 'modern' is just out of place/time now