Help! Brake pulsing

[Crickleymal]

I've got a pukka brake spanner from Halfords. Didn't work on my wife's Hyundai brake pipes. I had to use a Stilson in the end and the brake pipe was seized in the connector so it twisted. I saw it twist and went back but it was too late.

 

[Crickleymal]

OK I bled the rear brakes. No air in them at all. Brake feels firmer but on a run the pulsing is still there. I've got new rear pads arriving tomorrow so I'll fit them and see. It's possible that the pulsing is a bit better and with a bit if use they'll bed in and start working again.

picture of right rear disc

 

[Crickleymal]

Should I bleed them with the engine running or not? I did them with it off and got an ABS light for a short while.

 

[Joderest]

That looks the same as the rear disc's i had on ML. I replaced them, and issue was resolved.
It could well be that one is warped, They are easy to replace, but that has to be your choice, its possible that pads will help. But why do half a job ?, they do not cost much.

 

[littleowl]

I don’t know if it’s comparable, but my motorbike had brake pulsing after only 3k miles (I bought it from new). It had its disc replaced under warranty, all was well for another 3k miles or so, then it started again. Had it replaced once more, along with the calipers, and so far it hasn’t returned although I haven’t done many miles in it. Ducati would not admit to any fault on their part (well they wouldn’t), even though I subsequently found out on Ducati forums that it happened to more than a few people on the same model of bike.

 

[Crickleymal]

I'd replace the discs today but by the time they arrive we'll be on holiday.
I'l order some in for when we get back.
Someone somewhere (motorbike forum i think) had a theory that keeping the brakes on when you' come to a halt migrated some material from the pads to the discs. So the discs didn't warp as such bit had high spots which caused brake pulsing.

 

[Joderest]

Bit of a misconception. If you hold brakes on after a long stop, the heat generated by the pads could cause a hot spot on the disc leading to warpage of the disc.
The preferred method to clean discs is to brake hard from about 50 mph, and release the brakes at about ,15 to 20 mph to avoid heat transference

 

[PobodY]

Also not setting the parking brake on red-hot discs helps. - Ever notice that race cars tend to chock the wheels instead?