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Help With Brakes


Paul Laing

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Since changing my brake pads over i've experienced some juddering on my steering wheel. I know the front wheels need balacing as since i put them on it vibrates slightly at 80, and the back ones have just been balaced when the tyres went on so it's not those juddering.

 

I've bedded them in but when doing 100 and over they judder like mad and also pull the car slightly to one side :conf:

 

The pins were siezed in when we changed them so we had to actually take off the left side calipers as they were the worst, could they just need bleeding? As they could have air in the system from taking the caliper off.

 

I thought about taking the brake cap off but it's a no return valve isn't it? The brake fluid goes in but doesn't come back out that way so i don't really know what it could be.

 

the brakes are Hawk HP Plus ones, any help?

 

thanks,

 

Paul

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the only time I EVER had wheel wobble was due to a faulty rotor.

 

Made the steering wheel judder under braking and at speed.

 

The scond I replaced it the problem went.

 

I doubt you would get judder from calipers as they are not part of the rotational mass that could make a judder.

 

:music:

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Originally posted by Paul Laing

Since changing my brake pads over i've experienced some juddering on my steering wheel. I know the front wheels need balacing as since i put them on it vibrates slightly at 80, and the back ones have just been balaced when the tyres went on so it's not those juddering.

 

I've bedded them in but when doing 100 and over they judder like mad and also pull the car slightly to one side :conf:

 

The pins were siezed in when we changed them so we had to actually take off the left side calipers as they were the worst, could they just need bleeding? As they could have air in the system from taking the caliper off.

 

I thought about taking the brake cap off but it's a no return valve isn't it? The brake fluid goes in but doesn't come back out that way so i don't really know what it could be.

 

the brakes are Hawk HP Plus ones, any help?

 

thanks,

 

Paul

 

Can you tell us if they judder ONLY when braking or does this happen all the time at speed?

 

If a wheel is out of balance they will judder all the time (at speed). If this only happens under braking, then the problem is with the brakes.

 

HTH

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At 80mph the wheel wobbles which is down to the front two needing to be balaced i think. It stops under that or over it

 

The wheel judders alot when doing say 100 plus then stamping on the brakes. If i took off both passenger calipers there must be air inside, i kept the same fluid for now and just put grips on the pipe going into the caliper to stop the fluid going everywhere.

 

Paul

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OK, so you've removed the brake flexi hoses form the calipers.

 

They will have to be bled.

 

Wasn't sure when you said you had removed the calipers if you just meant that you had removed them form the hub assembly to get the new pads in, but left the brake lines connected.

 

Any time you open up the fluid system, (i.e. by undoing on of the unions on a brake line) you introduce air. This has to be bled out.

 

However, this alone does not cause the wobbling you describe. THis has to be either something out of balance or something not running straight, such as a disc with dirt under it as Chris suggested.

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Originally posted by Paul Laing

Can you get to them without taking off the wheels?

 

Paul,

I know you had a go at me before hwen I suggested you get someone who knows what they're doing to do this, but seriously, you are asking very basic questions here and you obviously haven't done this before.

 

I'm not trying to put you down, you obviously want to learn about your car and that can only be a good thing. But get a mate or someone who has done this before to show you/give you a hand.

 

Have you got an old Haynes manual lying around for one of your previous cars? That will tell you how to bleed your brakes and willl have some pictures to boot! It's pretty much the same process from one car to the next.

 

But you must do it right. We can all tell you to a point how this is done, but if you are determined to do this job (and you obviously are) then get hold of an old Haynes manual. It's not too difficult to do but if you get it wrong it could be disastrous.

 

Just don't want to hear about another damaged Supe.

 

:)

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Thanks for the advice everyone, really appreciated.

 

I have never changed the brakes before as you can tell lol, but my dad has done loads before, aswell as swapping engines etc but i just wanted to know a few things so that when we do bleed them i'm not lost off if you know what i mean.

 

It would be nice to know what he's doing instead of watching :)

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Originally posted by Paul Laing

They arn't warped disks, as they were perfectly fine before i changed them so it's definetly not that. I'll give bleeding the brakes a go, is there something i have to do with the UK traction control system?

 

Paul

 

So its not possible that the brake pad has been continuosly rubbing on your disk due to a dodgy piston and casued your disk to heat up to a million degrees each time you take it over a ton?

 

That would certainly warp your disc and is also something that can realisticly happen. As it did to me:(

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When? Since i changed the pads do you mean? Because the brakes were fine before then, and it's only when going over 100 the judder occurs.

 

When feeling the disk there no marks or ridges, so everythings ok with the disks. They wouldn't warp just by changing the pads surely?

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Yes, this could happen and you would not be able to see the mis-shaped disc without removign it and placing it on a very flat surface. (An old sheet of glass is good for this.) Then look for gaps between the disc and the glass.(Or whatever flat surface you have chosen)

 

However, if a brake was binding on, you would probably have noticed that when you put the wheel back on, it was difficult to turn. Did you notice any resistance when refitting the wheels?

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Paul, what can happen is:

 

You put new brake pads on that makethe piston sit another 15mm back in the caliper as they have extra pad over your old worn ones.

 

Becuase your car is a lardy UK and has had years of salt corrosion it is possible to have a sticky piston that is holding your brake pad on your disk. This doesn't have to be hard enough for you to notice it but the friction would heat the disc up to a point that they could warp. Especially if you are doing 150mph!!:)

 

You may also not notice the discs are waped as they can warp axiallly, like a buckled bicycle wheel. Which will cause vibration when braking.

 

A small buckle would be noticed a higher speeds as the buckle would pass the pad more frequently and resonate through your steering.

 

Although, you would also expect the disc to look like it been subjected to bit of excess heat. Still, i wouldn't rule it out:)

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