Brake Issues!! Please help.

mills_88

1 AYC Bar
Location
Perth, WA
First Name
Matt
Drive
Toyota Supra RZ - The Project
Holden Commodore SS VF Series 2 - The Daily
Well im hoping somebody is going to be able to shed some light on the cause of this problem im having because me and my dad are completely out of ideas as to what could be causing it.

The problem: As i brake from around 100km the steering wheel and the entire car except for the brake pedal start to shudder. As i pass about 70km/hr the entire car starts to shudder like crazy, enough to rattle fillings out ya teeth. then by 50km/hr it is gone. then (this could be unrelated) as you come to a stop the brakes make a sort of clicking noise.

Things we've tried:
1- Got the mic out and checked the discs were the same thickness all the way around which they were.
2- Checked the calipers werent loose which they were not.
3- Checked the pad material (plenty left) and if they were loose which they were not.
4- Checked the steering rack wasnt loose which it wasnt,
5- Checked the wheel bearings wasnt loose which it wasnt.
6- Checked the wheels themseves were not buckled which they were not.

Am going to get a wheel alignment done next week but dont think this will help as the problem only occurs when the brakes are applied. Also the brakes are completely standard.

Hope someone can help because me and my dad whose been an engineer for the last 30 years are completely out of ideas.
 
G

Guest

Unregistered
have you had the disk's skimmed?? (there not warped??)

have you checked the slipers on the calipers (there not seized or jamming?)

have you checked any of the suspesion bushes/ball joints??
 

VR-04-TT

1 AYC Bar
Location
NSW
First Name
Paul
Drive
2005 Liberty 3.0R Spec B
Just throwing an idea around, could be hogwash, but I'll say it anway.

Could it be something loose with the suspension that, when braking, causes it to lose stability, but under accelleration and cruise the geometry/force keeps the loose parts stable? The click could be these going back into place?

If you had any "warping" your pedal would be pulsing.
 

weeaazz

Leaving Skid Marks
Location
qld/noosa
First Name
james
Drive
legnum
possibly badly warped brakes,mine used to do it,never that bad and i just bought new pads and rotors and it never happened again
 

mills_88

1 AYC Bar
Location
Perth, WA
First Name
Matt
Drive
Toyota Supra RZ - The Project
Holden Commodore SS VF Series 2 - The Daily
Havent had them skimmed. But did check for thickness, didnt actually check if they were warped though as no way to check.
If you mean the metal thing the pad sit in then they are fine and yeah the suspension and that all solid.
 

J-B

Leaving Skid Marks
Location
South Australia
First Name
Jarrad
Drive
EVO VII GSR
I had the same problem, i was 90% sure that my rotor were warped as i found that braking when moving slowly i could feel them gripping then slipping again.

Cant give you a 100% answer as I just upgraded my brakes to Brembos and havent had a problem since
 
G

Guest

Unregistered
Ok just a rule of thum for detecting warped brakes.

If the steering wheel shudders then it normaly is the front discs. If the shuddering is felt thru the seats it would be the rear discs.

To further confirm is the part you said from 70km-50km it shudders then below it is fine. That points to the rear discs. As the rear brakes are realy only there to keep the back of the car inline whilst under hard braking. Aswell as assist the front brakes under emergency braking.
 

mills_88

1 AYC Bar
Location
Perth, WA
First Name
Matt
Drive
Toyota Supra RZ - The Project
Holden Commodore SS VF Series 2 - The Daily
Starting to think warped discs now, only reason i didnt look this way before is because my dad doesnt think the symptoms fit. But the shaking is through the wheel and i just cant think of anything else it could be so im going to replace the rotors and see what happens. Doubt its the rears cos when the handbrake is applied very carefully doesnt have the same effect
 

Hipsi

Leaving Skid Marks
Location
QLD
First Name
Trav
Drive
D40 Navara
other cause can be heat checks on the rotors. These are most evident on cars with plain rotors (ie, not slotted). On repeated heavy application of the brakes, hot gases build up between the pad and rotor and without the slots the gas has no way of being expelled until you release the brakes. These hot gases can actually cause hot spots on your rotors that then have different adhesion properties to the rest of the rotor surface. Shuddering is the result, and it gets worse over time.

check my post in the OZVR4 Shop for pricing on RDA rotors.
 
G

Guest

Unregistered
Doubt its the rears cos when the handbrake is applied very carefully doesnt have the same effect

Usually the handbrake wont be affected at all as the legnum/galant uses a mechanical drum style of system on the inside of the rotor hub sort of, hard to explain.... Therefore the rotor is not used and the warping wont effect the braking via the handbrake.

You did mention that the steering wheel was vibrating so That normaly leads to the font disk/rotor.
 

mills_88

1 AYC Bar
Location
Perth, WA
First Name
Matt
Drive
Toyota Supra RZ - The Project
Holden Commodore SS VF Series 2 - The Daily
Oh really, thats interesting. But yeah id say the front purely from how it feels.
 

matchtheclown

Time p33nt
Location
nsw
First Name
hugh
Drive
99 VR-4 Type S Man
Getting them skimmed wont cost you more than $50 at a decent brake workshop mate.

Just get it done first. Then see how it goes from then.
 

SiliconAngel

1 AYC Bar
Location
Perth, WA
First Name
SA, Trevor
Drive
'99 Legnum VR4 Black MT
I'm gonna have to go and disagree with you there, Hugh - Matt I recommend just replacing the rotors. If you just get RDA slotted rotors its really not very expensive to replace the whole lot and the stock items are known for warping - they just weren't engineered to handle the kind of temps you can build up under hard braking. Its a small price to pay for your safety and confidence in the car.

If you want to work out if the rotors are warped, you can test this by pulling them off and spinning them on something like a drill press or preferably a lathe. If they're warped the surface will rotate unevenly. But TBH I'd just take the excuse to replace them and be done with it - even if that ISN'T the cause (and it certainly seems to be from what you've described) it will be a big step in the right direction and make further trouble-shooting much easier, apart from the fact that you should just do it for safety reasons.

Oh and Tommo's right, the hand-brake is a drum brake inside the rear rotors. Its a common design used by Mitsubishi. No one ever recommends replacing the pads on the drums because they ideally shouldn't experience any wear, but if you ever use your hand-brake to deliberately develop oversteer its something you should keep an eye on.
 

naughtika

OzVR4 Stalker
Location
Brisbane, QLD
First Name
Christian
Drive
'96 Galant VR4, '17 MB A180, '25 Macan GTS
I'm with SA.. if your rotors are oem mitsubishi and are warped.. REPLACE THEM.. stock mitsubishi rotors SUCKS.. even if you get them machined and replace the pads.. they will keep warping until you need to replace them..

replace them with RDA and you won't be disappointed.. slotted or non slotted.. they are far better than the oem rotors..
 

mills_88

1 AYC Bar
Location
Perth, WA
First Name
Matt
Drive
Toyota Supra RZ - The Project
Holden Commodore SS VF Series 2 - The Daily
Replaced with RDA slotteds, and problem has gone away. Very happy with the RDA's so far. And thanks to Hipsi for great service.
 

Scubasteve

Leaving Skid Marks
Location
QLD
First Name
James
Drive
96 Mitsubishi Galant VR4 Manual
I have the exact same problem, Whats it cost for a set of RDA Rotors ? It only happened bad once, and i get a slight vibration now and then how damaging or danderous would it be to keep driving on these rotors?
 

Hipsi

Leaving Skid Marks
Location
QLD
First Name
Trav
Drive
D40 Navara
Hi Steve, I can only answer this by asking you a question. How much would you like to be able to rely on your brakes? If it were me, trust me I need to be able to rely on them 100%, I would be ensuring that they're operating as best as possible. Front slotted rotors are $250 and rears are $220. The Gold passivated ones are a bit more. Full price list is here
 
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