Brake Shudder

[yoshie]

It's not the tyres.

One thing no one has mentioned is material transfer. Long periods of braking, lets say from a high speed and then holding the brakes on when you stop create a massive hotspot. This doesn't generally lead to warping, but DOES allow the now hot pad material to transfer from the pad to the disc, effectively producing a high spot.
The next time you try and brake, the pad "jumps" over the high spot and causes judder.
This is well documented elsewhere, but I have never heard of it on these cars.
Warping a disc is a lot harder than you'd think. Again, this is well documented elsewhere.
As for the puilling to one side, I would assume sticking piston (ie not working) in offside caliper, very worn pads allowing over extension of piston causing the sticking) or a more discrete issue such as a kinked hose or dented pipe? Have you done any spannerwork in the engine bay? Worth checking the lines.

So posts 26 and 28 then.

[ads surf]

Theres been no work in engine bay to cause any problems but thats not to say there isnt a problem so i will check that out also. In the mornings when i first set off the first time i brake i still get the shudder when everything is still cold could there really be a hot spot so quickly with very little braking??

[Wolfracer]

So posts 26 and 28 then.

Okay, playing devils advocate here...

26 and 28 state "warped discs"

Did 26 and 28 measure the run out of the "warped disc" on and off the vehicle?

Did 26 and 28 try skimming the high spots off the affected discs?

Not saying their wrong, just saying its harder to warp a disc than it is to produce material transfer.

[yoshie]

Okay, playing devils advocate here...

26 and 28 state "warped discs"

Did 26 and 28 measure the run out of the "warped disc" on and off the vehicle?

Did 26 and 28 try skimming the high spots off the affected discs?

Not saying their wrong, just saying its harder to warp a disc than it is to produce material transfer.

[Wolfracer]

Theres been no work in engine bay to cause any problems but thats not to say there isnt a problem so i will check that out also. In the mornings when i first set off the first time i brake i still get the shudder when everything is still cold could there really be a hot spot so quickly with very little braking??

No, if it is material transfer, the issue has already happened and the disc is affected.
Imagine a lump on the disc, which pulses the brake pressure, effectively producing a vibration.
If it was MT skimming the discs will solve it, or buying "friction pads" which have a "sanding" effect on the discs to reduce high spots.
Normal pads are like an eraser, and can leave a residue on the disc.
Friction pads are like fine sandpaper and actually clean up the disc, but wear it away quicker as a result.

[Wolfracer]

Found it.

http://www.stoptech.com/tech_info/wp...rakedisk.shtml

[ads surf]

Ive learnt something tonite. i never relised the pads could leave a permant residue on the disc. It all makes sense, not to say thats the problem but it definatly gives me something to consider.

[Sancho]

No, if it is material transfer, the issue has already happened and the disc is affected.
Imagine a lump on the disc, which pulses the brake pressure, effectively producing a vibration.
If it was MT skimming the discs will solve it, or buying "friction pads" which have a "sanding" effect on the discs to reduce high spots.
Normal pads are like an eraser, and can leave a residue on the disc.
Friction pads are like fine sandpaper and actually clean up the disc, but wear it away quicker as a result.

It's not material transfer.

[Wolfracer]

It's not material transfer.

Why?
Genuine question. Don't surf's suffer this?

[Sancho]

Why?
Genuine question. Don't surf's suffer this?

No idea. It's just you said "it's not the tyres" so I thought I'd make a statement with no explanation too...

Sorry, just in one of those moods.

Seriously, I doubt it is material transfer as that would tend to happen with very heavy braking from high speeds rather than the more sedate braking of a surf, which barely manages to actually stop the thing even when it's all good.

My opinion is that it's probably a combination of using old parts and not fitting them 100% correctly, but that's the genius of a forum where everyone has a different opinion: someone's going to be right and they get to feel all smug like they're a genius and everyone else is stupid.

[BUSHWHACKER]

Yep, I've already said what the problem is and how to cure it.

[hellmett]

re

I had a very similar problem.

Done everything that was possible to do with the brakes.

New this, new that and new the other!

Turns out that it was probably the wishbone bushes!!!!

Replaced them (very difficult job single handed) and the problem was cured!

http://www.hiluxsurf.co.uk/showthread.php?t=61590

[ads surf]

yeah i think with the information i have i reckon i have a fighting chance in solving this problem wish me luck and i'll let you all know how it went.

[Wolfracer]

No idea. It's just you said "it's not the tyres" so I thought I'd make a statement with no explanation too...

Fair enough. should have said - I just don't see how a tyre changes it's behaviour from being spun around feely, to being slowed under a constant force.

Actually I don't think it's MT either as there would be more instances of it, but as I said, no one had mentioned it, and the op still has issues so just throwing it into the pot.

So, who's right....?

[Albannach]

Me.