MOT fail: front brake balance. Any ideas?

[The_blue]

Just failed the MOT on 2 easy things and the brakes.

Bloke says the front brakes aren't balanced. He suggested it might be a sticky pad.

Never noticed till i jacked it up today that it's a double cylinder setup.

The old owner looked to have put new disks and pads on the front when we got it, now the o/s outside pad doesn't look as worn (maybe 1.5mm thicker).

Are their any well known issues with the brakes on a '82 2l CU van?

What are the things to look for and how can i tell myself if its OK? I prefer things that snap and can be replaced, end of! Had the exact same issue on the mondeo 2 months ago.

[gti mad man]

lazy caliper maybe

[The_blue]

Could be!


How can i motivate it?

[toomanytoys]

drop the caliper off and gently press the brake pedal watching what the pistons are doing.. if one moves a lot more than the other, then restrict that one and press again.. if it still doesnt move its seized /nearly seized... only thing to do then is to try and push it back in and work it in and out a bit.. or you could rebiuld caliper with new seals or exchange the caliper.. but its worth considering doing both then as the otherone wont perform as awell as the rebiult/exchange one..

[The_blue]

Ta!

Problem is that i could realy do with an MOT for friday.

I'll try working them in and out.

[Ian Hulley]

http://archive.club8090.co.uk/viewtopic.php?t=33858



If I were you I'd have em anyway .... for a rainy day.

Ian.

[The_blue]

http://archive.club8090.co.uk/viewtopic.php?t=33858



If I were you I'd have em anyway .... for a rainy day.

Ian.

Ready for next time

Should have MOT'd the bus 2 weeks ago but booked a last minute holiday instead... Paying the price now!

Just hope i can work out the issue this afternoon.

[cumbriankeith]

I've had a sticky piston for a while - it was stopping one pad from wearing while the one on the other side of the disc did most of the work - didn't seem to show up in braking performance - tho got thro an MOT like it!
Mine are Teves (or ATE) versions and I've rebuilt both sides now with seal kits - but not split the calipers completely. My experience shows that the outermost pot gets more weather and on both calipers was very rusted near the outer end and therefore stuck. The Haynes ploy of using an airline to push the pistons out didn't work and I had to reconnect the hydraulics to press them out.
Then I stripped, cleaned and derusted the bores and pistons making sure I didn't spoil the sealing surfaces, before reassembling with new seals, lubed with brake fluid - and new nipples. Seal kits are about £15, nipples £3 from JK - kits are really hard/more expensive to get anywhere else. All in all better than £80 or £90 depending on source for a new or remanufactured one, - as long as the polished "sealing" sector of your pistons are not affected.

[The_blue]

Bah! Failed again!!!!!!


I found the outside N/S cylinder was stiff but after a little oil under the seal and a few minutes pumping it out and pushing it in all looked and felt good... Also bled the front both sides.

What now?? MOT bloke suggested bleeding the whole system as he could feel a little sponge before the N/S come on so i have done.

Original figure was 31%, retest was 29%. Need to hit 25%

[CycloneMike]

Now come on I don't want to lecture, but these are your BRAKES.
The 25% maximum imbalence allowed for the MOT is for the safety of you and everyone else on the road, its not a target we should aim to just scrape through. If you do get to 25%, they are not going to get any better, more likely worse again before your next MOT.
Yes you can rebuild them, but I recently had my Girlings reconditioned for £53+Vat (each) by Brake Engineering via TMS. ATE calipers were even cheeper at £43+VAT IIRC. Hardly worth getting you hands dirty and they should work like new.
I apprieciate you are on a deadline, But I'd hate for you to come to grief!

[IMG:640:480]http://i253.photobucket.com/albums/hh74 ... 008231.jpg[/img]

[Grun]

The_blue,

If all the pistons are now working properly, and there is no air in the system, surely friction surfaces (Discs and Pads) are the next suspects.
How about swapping the pads side to side (NS to OS) and seeing if the problem switches sides, or better still, fitting a new set.

The pad that you said appeared less worn (Offside outer) was not the one on the sticky piston (Nearside outer) a bit strange.

Always a chance that the previous owner has left you with a mixture of pad materials.

'CycloneMike' posted while I was typing......... and really that is the way to go.
Nice to know some things are still available so cheaply.

Mike

[The_blue]

The_blue,

If all the pistons are now working properly, and there is no air in the system, surely friction surfaces (Discs and Pads) are the next suspects.
How about swapping the pads side to side (NS to OS) and seeing if the problem switches sides, or better still, fitting a new set.


Mike

Winner!!

Did just that and it passed! Almost even now

[Grun]

The_blue,

Glad you're sorted,..... (after the usual team effort).......... it's an 80-90 thing.


Mike

[kevtherev]

shucks Mike, I've gone misty eyed...what a thread!

[The_blue]

Group hug time!

[img:395:359]http://www.grassroots.com/images/2007-0 ... 95wide.jpg[/img]