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Sierra front axle's with powerlites
Harquil1908 - 28/3/17 at 01:18 PM

Hi chaps.

Hopefully going to get round to bleeding my brakes at the weekend but I think I might have come across a problem!

I've got a pair of sierra axles on the front with wil wood powerlites with solid discs.

When I put the calipers and disc's on everything went on fine and moved so I thought nothing of it but this last weekend I got the car up on its stilts one wheel is turning fine but the other was dragging a little and sounded like something was rubbing.

On closer inspection I can see that the inside brake pad is rubbing on the disc. The calliper is hard up against the axle and I tried to see if the brake pad might move back a bit but it won't.

I'm wondering if I need either bleed the brakes and see if it'll correct its self or is it possible to get axle's ground down? Weird that one should do it if the other is fine?

Any help muchley apprectiate.


mcerd1 - 28/3/17 at 02:15 PM

Are these calipers / discs new - or have they been on the car before ?


Do the discs line up nicely in the middle of the calipers ?


Is one (or more) of the pistons in the caliper stuck and preventing the pad from retracting fully ?
(if so you'll want to free it off and make sure its fine before you do anything else)


Is there any sign of damage to the caliper mounts or the lugs on the sierra uprights ?


Harquil1908 - 28/3/17 at 03:42 PM

Everything is brand new yes apart from the uprights.

I never thought to check if it was in the middle of the calliper without the pad in, will double check that and make sure the pistons aren't stuck. I did try and give the pistons a little push and they didn't move but maybe I need to push a little harder.

If the disc isn't in the center without the pads in what options do I have?!

Can't see any damage to the uprights


indykid - 28/3/17 at 06:03 PM

Either slacken off the caliper bolts (the radial M10 cap screws that hold the caliper to the bracket) and move the caliper, or if you need more adjustment still, shim/machine the bracket block where it mounts to the lugs on the upright.


Harquil1908 - 28/3/17 at 08:09 PM

Any idea where I could get the uprights machines if it comes to that?


CosKev3 - 28/3/17 at 09:47 PM

Discs can be slightly off centre and cause no issues,the only time you will notice it is when new pads are fitted.
I would compare both sides,if it's just a case of a couple of mm max I would be inclined to take a little bit off the face of the pad


mcerd1 - 29/3/17 at 08:52 AM

as above if the disc isn't perfectly centred its not the end of the world - but it should be near enough and the caliper should sit nice and parallel to the disc

quote:
Originally posted by Harquil1908
Any idea where I could get the uprights machines if it comes to that?

you really shouldn't need to do that - its the bolted on brackets that you would normally modify / shim to get them to line up

have you got any pics ?

[Edited on 29/3/2017 by mcerd1]


Harquil1908 - 18/4/17 at 06:31 PM

Sorry for the rather late reply. I've only just managed to get into the garage to look at the car. So the disks are central to the Calipers and match the other side when the pads are taken off so would this suggest that the brake pads need taking down a bit? And if so how do I go about it?

Cheers


CosKev3 - 18/4/17 at 07:37 PM

Are you sure the pistons are pushed right in?


hkp57 - 19/4/17 at 06:41 AM

Get the brake system filled and bled, after its bled and you have stood on the pedal a couple of times check again.

If its a rub that is making it difficult to turn the wheel then yes it needs shimmed or machined or thinner pads.

if its just a noise and not a noticeable resistance then it will sort itself out bedding them in in use.

monitor brake rotor temp for signs of binding on one side

When you say the caliper is hard against the axle, do you mean the inboard end? pics may help!

[Edited on 19/4/17 by hkp57]


Harquil1908 - 19/4/17 at 08:11 AM

Yeah I double checked the pistons were pushed all the way in coskev but they spring back out again. I'm hoping once the brakes are bled it'll sort its self out, just annoying as it's only on one side. Sorry should have taken some pics, will try today.


procomp - 19/4/17 at 11:26 AM

Hi.

The mounting brackets that come with the wilwood calipers are notorious for being wrong ( made in china ).
Remove the pads and double check that disc is running in middle of caliper. you may find you need to either machine a bit of the mounting bracket or add a shim on mounting face to upright.

Cheers Matt


procomp - 19/4/17 at 06:33 PM

Also it just occurred to me that the only pads that fit that kit are the Mintex that RD sell and the willwood smart pads.
They are substantially thinner than what you would see on standard road cars.

Cheers Matt


Harquil1908 - 19/4/17 at 09:01 PM

Hi Matt

I did check to see if the disk was center to the calliper and it is so I'm assuming it must be the pads. Think I got just some standard wilwood brake pads to start me off, if memory serves they cost about £40 so maybe next time I'll get some thinner pads.

Jim