BRAKE SHUDDER ISSUE

[sexual harrassment panda]

Definitely a lot better with all the front bushes replaced, hubs and rim mating surfaces cleaned and wheel nut tension checked regularly.

[gemms61]

I thought I'd check with Wholesale Suspension what's involved in the bushes, fell over when told its about $550.

I'll get a set of rear DBA,s tomorrow off Vic performance and see how it goes.

Thanks again for the input.

[aiboart]

I have run through at least two sets of DBA5000 T2 slotted and a set of factory Premium discs with no issues whatsoever. The brakes were perfect.

Now running a new set of DBA5000 T3 bidirectional slotted (2000km) and new Ford Premium Brake pads and:

• experiencing severe shudder on light braking but only at speeds over 80kph.
• no shudder whatsoever below 80kph.
• no shudder on hard braking, anywhere at anytime - all smooth.
• light braking above 80kph will incite sever shudder, however, adding more braking force will stop the shudder and provide smooth braking.
• applying high braking force rapidly will preclude any shudder

The brake pads have remained constant for all applications - Ford Premium Brake Pads.

All the new discs and pads go through a dedicated bedding in sequence on open roads over a period of some 40 minutes.

Brake experts installed the brakes as they have previously. They have subsequently reviewed the braking system for dirty hubs, witness marks on the hats, balanced the wheels, reviewed the bushes. No joy.

Now considering that there may be pad vibration due to a number of causes including air (though the brakes are absolutely rocks solid always...due to DBA braided lines), or, some weird harmonics generated as a result of the T3 asymmetric (from the L-R side of the car) slot pattern.

Edited 09/04/13 09:57 PM by aiboart

[gemms61]

I have run through at least two sets of DBA5000 T2 slotted and a set of factory Premium discs with no issues whatsoever. The brakes were perfect.

Now running a new set of DBA5000 T3 bidirectional slotted (2000km) and new Ford Premium Brake pads and:

• experiencing severe shudder on light braking but only at speeds over 80kph.
• no shudder whatsoever below 80kph.
• no shudder on hard braking, anywhere at anytime - all smooth.
• light braking above 80kph will incite sever shudder, however, adding more braking force will stop the shudder and provide smooth braking.
• applying high braking force rapidly will preclude any shudder

The brake pads have remained constant for all applications - Ford Premium Brake Pads.

All the new discs and pads go through a dedicated bedding in sequence on open roads over a period of some 40 minutes.

Brake experts installed the brakes as they have previously. They have subsequently reviewed the braking system for dirty hubs, witness marks on the hats, balanced the wheels, reviewed the bushes.

Now considering that there may be pad vibration due to a number of causes including air (though the brakes are absolutely rocks solid always...due to DBA braided lines), or, some weird harmonics generated as a result of the T3 asymmetric (from the L-R side of the car) slot pattern.

Had a chat to someone in the trade today re the shudder, seems to think its the design and size of the calipers that's the culprit, apparently when braking they flex and eventually puts the root r out of shape.

Apparently previous models had it worst until they changed the caliper design?

I don't know enough about brakes to comment but made sense.

[gemms61]

Hi boost69

Tried to change the rear rotors today and couldn't get them off, I didn't want to go taking everything apart (in case I couldn't put it together again) so what exactly did you take off or loosen so the rotor would spin?

Cheers

Yeah rears are as straight forward as the fronts, though what I did fid when I did mine on the BF is that the rotors wouldn't come off the studs.

I had to undo the handbrake so the rear wheels would spin freely, then they just loosened off the studs...

Though I have gone down the path of changing rotors to dba 4000 and using Bendix Ultimates allround, and like yourself I found that the shuddering always came back.

Never really found a solution for it, even did the cleaning of the wheel hub thing...etc...

My shufddering would always start off gradually after the rotors were replaced or machined, with a slight pulse in the peddle and then before you know it would progress to the steering wheel.

[boost69]

Hi mate, maybe I used the wrong terminology, what I meant to say is that I just put the handbrake leaver down, which allowed the rear wheels to spin freely.

Once you have done this, If you give them a bit of a nudge they should just pop off the threads.

Other wise a couple of light taps on the side of the rotor with a rubber mallet should get them unstuck.

[spinr33]

Did u have the hand brake on or off mate ?

[Ralph Wiggum]

if they rotors are not moving and the Handbrake is off, try and do it whilst the brakes are still hot. Plenty of WD40 and good few whacks with a mallet will free them up if they are siezed on the centre bore.

[gemms61]

I did have the hand brake off but the rotors wouldn't turn or budge, and I gave them a couple of good whacks with a bloody big hammer too.

Ill try again on the weekend but ill make sure the wheel is free while their still on the car, should give me more leverage rather than playing around with the smaller rotor.

well thanks for your quick replies, at least in know I'm on the right track.

Cheers

[gemms61]

Ok, All good, a few wacks with a big hammer and finally got the rotor off. One thing had me stumped, what is the plate between the rotor and wheel for? I put it back on but not sure why as I cant see any reason why its there. Possibly to cover up the ugly rusty oem rotor but since the new DBA rotor is painted black I cant see any other reason.

Could anyone let me know what its for?

Cheers