About 3 months ago I changed the rear discs and pads on the Xantia - the other discs were paper thin and heavily corroded on the edge, and the pads were slightly unevenly worn around the top edge.
Did the job as per Haynes but the workshop I used didn't have any Copper Ease so being in a rush I put them back in without and drove round for a few weeks. After this the rear brakes made a horrendous squealing at low speed braking.
When I did the job the pins that hold the pads in place across the top of the caliper were a bit rough, so I bought a new pair and new nuts and washers from the dealer. I removed the pads and they were worn with a 1mm wide lip - the pads had obviously been riding over the edge of the disc.
I gave the pads a good smear of copper ease, scrubbed the pads flat again and refitted them with new pins, having tapped the pads down as far as I could. All has been well for about 8 weeks and today the horrendous screaming has started again, only worse than ever!
The original pads on the car did not have shims, the pads I've bought (AP Lockheed) didn't either, but Haynes says the pads should have shims fitted. Is this correct?
I'm at a bit of a loss what to do next, I've a feeling I'll find the same uneven wear again. The only reasons I can think of is that the pads need shims, the discs are ever so slightly too small causing the pads to ride over them, or the pads aren't to the exact spec and the friction material comes too high.
Any thoughts?
Xantia Rear Brakes
Moderator: RichardW
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Jon
Um, yes, a few thoughts.
1) The rears discs are actually Xantia ones, and not BX ones sold as Xantia by some Motor factors? The Bx ones are slightly smaller but fit!!
2) The rear pads. Most folk including our own Dave Burns would swear by Bendix or Textar for the rears to prevent squealing.
What I do when doing Xantia rear brakes is to deglaze the disc by turning it by hand and pressing emery paper to both sides, then, slide the pad up and down in and out of the caliper rapidly until it moves smoothly. Then coat both side edges of the pads with copaslip and work up and down in the caliper again before re applying the copaslip to the pad edges then a blob on the back where the piston touches.
That almost guarantees long rear pad life and squeal free braking. I also Copaslip the retaining bolt and the top of the pad where the bolt passes trough it.
Anyone? [;)]
1) The rears discs are actually Xantia ones, and not BX ones sold as Xantia by some Motor factors? The Bx ones are slightly smaller but fit!!
2) The rear pads. Most folk including our own Dave Burns would swear by Bendix or Textar for the rears to prevent squealing.
What I do when doing Xantia rear brakes is to deglaze the disc by turning it by hand and pressing emery paper to both sides, then, slide the pad up and down in and out of the caliper rapidly until it moves smoothly. Then coat both side edges of the pads with copaslip and work up and down in the caliper again before re applying the copaslip to the pad edges then a blob on the back where the piston touches.
That almost guarantees long rear pad life and squeal free braking. I also Copaslip the retaining bolt and the top of the pad where the bolt passes trough it.
Anyone? [;)]
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David Goddard
- Posts: 138
- Joined: 26 Sep 2001, 04:39
- Location: United Kingdom
- My Cars:
Jon -
It's known that most pads available are covered on the rear with a thick paint like hard mastic. This acts as sqeal damping against the pistons.
However I've noticed a couple of times that new pads (unknown origin) I've bought only had a thin layer of standard protective paint - and had a tendency to squeal awfully - right from day 1 of fitting.
this is my experience to both front & rear pads on several cars I've owned.
In past times it was possible to purchase a set of anti-squeal paddings to insert between pads & pistons - a rubber/fibre like material. And they did the job - helped instantly on the cars I tried.
The reason is that the sqealing originates from the friction between pads & discs - causing high frequency vibration between the hard (undamped) rear of pads & the piston surface - or high frquency tapping if you like.
The actual vibration is of course dependant on many factors - like pads & discs materials/composites - and any foreign influence on the surfaces - like stain, water, salt etc.
As to your description on pads replacing :
was it you over my neck last time I did mine [?][;)][:D][:D]
It's known that most pads available are covered on the rear with a thick paint like hard mastic. This acts as sqeal damping against the pistons.
However I've noticed a couple of times that new pads (unknown origin) I've bought only had a thin layer of standard protective paint - and had a tendency to squeal awfully - right from day 1 of fitting.
this is my experience to both front & rear pads on several cars I've owned.
In past times it was possible to purchase a set of anti-squeal paddings to insert between pads & pistons - a rubber/fibre like material. And they did the job - helped instantly on the cars I tried.
The reason is that the sqealing originates from the friction between pads & discs - causing high frequency vibration between the hard (undamped) rear of pads & the piston surface - or high frquency tapping if you like.
The actual vibration is of course dependant on many factors - like pads & discs materials/composites - and any foreign influence on the surfaces - like stain, water, salt etc.
As to your description on pads replacing :
was it you over my neck last time I did mine [?][;)][:D][:D]
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blueboy2001
- Posts: 423
- Joined: 29 Jan 2003, 04:16
- Location:
- My Cars:
The brake parts came from a local place called Trafford Brake Services, they do brakes for everything from cars to tractors. I used them because we had an account with them at work so I could get the stuff FOC on the jobs account; if I'm paying I always use GSF. The discs and pads were both branded Delphi/AP Lockheed and cost over £50+VAT so it wasn't cheap stuff.
To be honest I don't know if the discs are proper Xantia ones - any chance of the correct dimensions on a Xantia disc please so I can check?
I'll pop to Liverpool GSF in Walton tomorrow if I get time and get a set of Bendix pads - I used Bendix discs and Pads on the front and they've been fine so I'm happy to go with them again.
I did give the pins a bit of Copper ease when I did them. The old pads that came off had a real thick layer of something on the back - I presumed it was copper ease but it may be the anti squeal stuff Anders talks about. I'll pop into a Motor Factors tomorrow and see what they do.
I'll swap the pads, be very careful when fitting them, rub the disc down with emery paper and make sure the callipers are free from corrosion. If that doesn't fix it I'll drive it off a cliff!
To be honest I don't know if the discs are proper Xantia ones - any chance of the correct dimensions on a Xantia disc please so I can check?
I'll pop to Liverpool GSF in Walton tomorrow if I get time and get a set of Bendix pads - I used Bendix discs and Pads on the front and they've been fine so I'm happy to go with them again.
I did give the pins a bit of Copper ease when I did them. The old pads that came off had a real thick layer of something on the back - I presumed it was copper ease but it may be the anti squeal stuff Anders talks about. I'll pop into a Motor Factors tomorrow and see what they do.
I'll swap the pads, be very careful when fitting them, rub the disc down with emery paper and make sure the callipers are free from corrosion. If that doesn't fix it I'll drive it off a cliff!
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by David Goddard</i>
My rear brake squealed - reason, corrosion between the calipers and the cast iron rear suspension arm (electolytic corrosion due to alloy and iron in proximity, encouraged by winter salt!).
Solution: Scrapped the alloy clean, applied grease to inhibit a repeat, and the squeal went!
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote"> i'll second that,i would never replace these discs/pads without cleaning behind the caliper & rear arm.this also seems to cause the pads to wear at an angle.
My rear brake squealed - reason, corrosion between the calipers and the cast iron rear suspension arm (electolytic corrosion due to alloy and iron in proximity, encouraged by winter salt!).
Solution: Scrapped the alloy clean, applied grease to inhibit a repeat, and the squeal went!
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote"> i'll second that,i would never replace these discs/pads without cleaning behind the caliper & rear arm.this also seems to cause the pads to wear at an angle.
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Dave Burns
- Posts: 1915
- Joined: 14 May 2001, 05:30
- Location: United Kingdom
- My Cars:
- x 2
Rear disc for hatch is 224mm dia. x 9mm thick (minimum thickness 7mm)
http://am.brembo.com
Go to bottom right hand box and click on cars, all sizes of discs given plus fitting info and causes of possible faults, good site.
Dave
http://am.brembo.com
Go to bottom right hand box and click on cars, all sizes of discs given plus fitting info and causes of possible faults, good site.
Dave