disc brakes skiffing

[mrcrow]

I had my front discs and pads changed last year and they work well..just been through the MOT couple of weeks ago

 

recently whilst reversing from a parking space doing a left full lock the driver's side front disc brake made metal to metal grinding noises...but disappeared after a few hundred yards and with application of the brakes...

i have taken a photo of the caliper...best i could get with the wheel on and the pad seems to be ok...i noticed a bar going over from the inside of the caliper to the front..

a linkage to pull the front half of the caliper against the disc or steady it in some way.??

 

the braking on the move is excellent and the car pulls up on both discs equally

 

is there some lubrication required perhaps

 

cheers

geof

[Murdockman]

All bits need a good wire brush up to remove loose rust, the top  of the disc can be cleaned off with a edge of a file against the disc and turn  the hub around until all loose rust scales are removed, some  fitters  will tell you to hit it with a hammer to do this but  I would not recommend this way, the pads should have some silicone -anti-seize paste applied  to rear of the pads and and where they locate on the carrier  frame, also check slide pins as these are usually over looked when new pads and discs  are fitted, DO NOT USE COOPER SLIP GREASE,  if you look in picture you need to  also clean rust scales from the disc just above the pad as this can also cause this noise, not a major issue but will sort that noise out

[Madvlad65]

Is that a big crack along the calliper?

[Breezy_Pete]

That's a very good question. Can't be though, can it?

 

[sepulchrave]

It's a huge crack and another smaller one, that caliper needs replacing urgently.

 

Some idiot has smashed hell out of it with a lump hammer.

[AGFalco]

Shadow line from the flash. 

 

Thanks. AG Falco

[sepulchrave]

31 minutes ago, AGFalco said:

Shadow line from the flash. 

 

Thanks. AG Falco

 

Haha, so it is, I'm not really a 'visual' person.

[J.R.]

A week ago I would have been wondering what line you were all talking about

[Breezy_Pete]

I'm not sure what made the noise you heard, possibly just a stone caught between dust guard and disc, now departed?

 

As for the bar you mention going over the top of caliper and pads; there is another underneath. They are what prevent the caliper and pads being rotated around with the wheel and disc when you brake. 

[mac11irl]

2 hours ago, Wino said:

I'm not sure what made the noise you heard, possibly just a stone caught between dust guard and disc, now departed?

id go with this.. or it was caught behind the front pad - theres a single deep scoring line about 1/2" from the outer edge of the disc.

 

the thin black line along the caliper to the left of the pic, really does look like a crack rather than a shadow line though

[Phil866]

I frequently get small stones caught between the stone guard and the disc which usually squeal when cornering or braking. They sound like a dry overheating bearing! Reversing sometimes clears them, if not I poke the stone guard with a small hammer handle through a gap between the alloy wheel spokes which always lets the stone fall out.   

[mrcrow]

thanks all....taking all into consideration and even though no problems today....i will let the garage do an inspection and brake bleed...

 

for peace of mind....the rust suggestion now i look closer seems to be the most likely

 

good posts chaps

cheers

geof

[mrcrow]

P.S....took me a long time and a few youtubes to get to understand how this caliper is designed

looked up spare parts as well

all my other cars had the caliper where you take split pins out and slide out the pads etc...

[Breezy_Pete]

Have another look at this area in daylight and maybe take another photo without flash.  Assuming you find nothing remotely resembling a crack, I'd say there's no real need to get it inspected.  Pretty sure it's a shadow thanks to AGFalco's input.

 

On the other hand, various places advertise free brake checks so maybe just bung it into one of those for peace of mind, but beware of inevitable attempts at upselling if you do.  Might be better taking it to a known-to-you garage who might check it free of charge anyway.

 

 

 

[mrcrow]

thanks Wino...will get my real camera out in the daylight and do another shot...without flash but on high iso

 

just finished doing this shot off a youtube so i could get my head round the whole assembly and how the pads are changed...would have to do it myself to appreciate how easy it is in the video

cool bit of design

 

cheers

geof

 

 

[UrbanPanzer]

On 04/12/2020 at 19:46, sepulchrave said:

It's a huge crack and another smaller one, that caliper needs replacing urgently.

 

Some idiot has smashed hell out of it with a lump hammer.

 

What was it you said to me..............

 

Are your eyes ok?

 

[sepulchrave]

8 hours ago, UrbanPanzer said:

 

What was it you said to me..............

 

Are your eyes ok?

 

 

Do try and keep up, I realised my mistake three hours after that post, not three days.

 

On 04/12/2020 at 22:33, sepulchrave said:

 

Haha, so it is, I'm not really a 'visual' person.

 

[Breezy_Pete]

In your last image from that video we can see the vertical/horizontal edge in the casting that we were looking straight down on before, giving the crack illusion. Black arrows added to attempt to show where I mean.

 

[mrcrow]

thanks Wino...

will get that photo soon...if the sun stays out...and the rain stays off...

 

i have looked at automotive disc brake calipers and got ductile iron...as opposed to cast iron which can fracture...?

i am hoping this line is from process which made the caliper..perhaps drop forged and not in a stressed area when the caliper compresses the disc with the pads

i will put a stanley knife blade in it to see if its deep

and

if its sunny and dry get a photo

thanks again

cheers

geof

Bit of fun here....joke could be on me..

[Breezy_Pete]

I promise you that there is no crack, you're just looking down on that right-angle feature of the casting. At the outer end of your first photo you can just make out the vertical section

[mrcrow]

26 minutes ago, Wino said:

I promise you that there is no crack, you're just looking down on that right-angle feature of the casting. At the outer end of your first photo you can just make out the vertical section

WINO WINS

 

i just had another clip done and its pretty clear here

 

bit thanks to you...got my brain in gear....

 

cheers and thanks again

geof

[Breezy_Pete]

Not me, that was @AGFalco's win, I just worked with what he provided. 

[AGFalco]

What did I win??

 

Thanks, AG Falco

[UrbanPanzer]

14 hours ago, sepulchrave said:

 

Do try and keep up, I realised my mistake three hours after that post, not three days.

 

 

 

Shame you don't realise just as quick to have a sense of humour.

[sepulchrave]

3 minutes ago, UrbanPanzer said:

 

Shame you don't realise just as quick to have a sense of humour.

 

It is humour, just wry and dry is all.