Front Brake advice please.

[axxeman]

Changed my front pads and discs last week whilst doing the n/s wheel bearing, as they were very badly worn down and an advisory on the recent MOT. All went very smoothly but I am getting a weird noise on the o/s under gentle but firm pedal pressure; there is a sort of rapid ticking noise which is related to the speed of the wheel; it gets slower as the van slows...

The van stops OK but obviously I'll need to look at this. What I did do;

1. Cleaned the new discs both sides to remove the oil film
2. Torqued the bolts up to the correct settings (double checked too)
3. Removed and wire brushed the bolt on part of the caliper (carrier?) and greased the pad locating grooves lightly
4. Greased the ends of the pads and put some on the rear too

What I did not check was the state of the caliper pistons. I had to push them back a long way in order to renew the brakes and I am wondering if perhaps there might be some corrosion on the piston which is fouling on the rubber seal and causing this problem? I imagine that the brakes may have been worn low for some considerable time and so the piston has been extended for longer than normal. As the brakes had been working fine, and the rubber boots looked good, I neglected to peel them back and inspect.

I remember years ago doing some cleaning up on brake caliper pistons with very fine emery paper to 'polish' the rust off.

Thoughts, please?

[blue estate]

What van? Could be the hub nut cover

[axxeman]

What van? Could be the hub nut cover

Connect 04 Tdci LX220

[gt_addict]

You haven't got a chip or donk in your disc have you?

[axxeman]

You haven't got a chip or donk in your disc have you?

Didn't see anything when I cleaned them prior to fitting...

With more thought, the o/s piston was tougher to push back into the bore. Maybe should have rung alarm bells there and then. Guess I should order a repair kit and totally dismantle and service them as I bet that exchange units are going to be too dear for my pocket.

On further thought, the pedal goes from a 'tick' to a rubbing, almost pulsing, judder in the last couple of metres coming to a standstill.

This'll teach me not to be lazy and investigate more thoroughly.

[BIG E]

I had a similar noise when i replaced my pads.It turned out to be the paint coating on the pad lugs was too thick and it stopped when i filed the coating off the lugs.

[gt_addict]

Disc seated on the hub nice and flat?

[axxeman]

I had a similar noise when i replaced my pads.It turned out to be the paint coating on the pad lugs was too thick and it stopped when i filed the coating off the lugs.

Interesting... I did file the pad end lugs as they ALWAYS tend to stick or jam in the slides from the burrs that are made when they are pressed out of sheet blanks in the factory, and subsequently get painted over. Worth another look.

By the way, the van doesn't pull under braking, it keeps gun barrel straight.

Thanks.

[axxeman]

Disc seated on the hub nice and flat?

I'd hope so but another possibility, thank you. Mind you, there's no discernible rubbing or drag under normal driving...

[gt_addict]

Only course of action for me would be take it all off again and go over with a fine tooth comb.

[axxeman]

Only course of action for me would be take it all off again and go over with a fine tooth comb.

Agreed. I hoped that it was bedding in but I really don't think so...

Any good links for piston and seal kits?

[axxeman]

Well, I dismantled the nice new brakes on the o/s. Checked the caliper piston for damage or rust and found it to be nice and shiny under the seal. Checked disc for run out - none. Went for another test drive and still clicking and pulsing as you come to standstill. Started to suspect the ABS so popped into local boys to see if they had any ideas...

Plugged their diagnostic in and two front sensor codes came up. Cleared codes and test drove and the o/s code returned. Put it into real time analysis to monitor the speed of all four wheels. Off side front showed 0 mph all the time so either dirty connection, or new sensor required.

Happy that it wasn't my DIY skills to blame - and only charged me a tenner for the help. Happy days.

Cheers guys.

[axxeman]

Checked sensor and found no output so wait for new one to arrive. Why does everything go wrong all at once!