GTR Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
29 Posts
Discussion Starter · #1 · (Edited)
Hi Guys,

Just wondering what others are getting in mileage from the OEM Brakes?

Mine has done 12,000 miles and not been on a track and I have done the last 8000 miles which has some occasional spirited driving but nothing hard on braking, never had brake fade for example.. Also the original Dunlop RF managed 10,000 miles and changed with about 3mm left on them which would indicate the car hadn’t been driven too hard.

Then one day last week suddenly from nowhere after braking a couple of times and the brakes were warm there was a juddering through the steering wheel and brake peddle and this came from no where and went as soon as the brakes cooled down again. This now comes back everytime the brakes are warm and goes again as soon as they have cooled.

My previous experience of when discs have warped on other cars is they gradually start to Judder and get worse and worse until they get changed, however the Judder gets worse and worse when the discs are getting hotter and then the Judder vanishes as soon as they are cooled again.

My last GTR had 20,000 miles on when I sold it and this was still on original discs and pads, hence 12,000 seems a bit low.

Any ideas? Or was I just lucky with the last GTR with getting so many miles out of the brakes? Thanks in advance
 

·
Registered
Joined
·
413 Posts
I've had OEM brakes on my first 4 GTR's and never changed them until I did 4 track days on one of the cars.
 

·
Premium Member
Joined
·
3,454 Posts
Check to see if there are cracks around the drilled holes if they are oem discs.
 

·
Vendor
Joined
·
8 Posts
Decided to comment on the issue as I previously had a lot of experience with brake judder.

Actually, the matter is a tad more complicated than it might seem from the traditional point of view.
There are three major reasons for brake judder in decreasing order of probability:
1. Distortion
2. Thickness variation
3. Run-out


1. Distortion commonly happens when the disc is overheated or shock-cooled (think hitting a puddle of water during a spirited drive). Significant disc wear and brake pads inadequate for actual use can all contribute to overheating. Incorrect brakes warming and cooling procedures on a race track are also likely to cause this.
Probability: This is the #1 reason for a noticeable judder
Common symptoms: Juddering usually less severe when cold and very noticeable on hot brakes
Solution: Discs and pads replacement only

2. Thickness variation is caused by local spots of hardened disc material due to local overheating. It causes the brake pad to 'jump' resulting in judder.
Realistically, in most cases, this happens when pad material transfers either due to corrosion (example: car washed and parked without drying brakes) or static melting (example: you braked hard to a full stop and keep pressing the brake pedal to hold the car still). Local overheating can also easily happen after brake discs developed considerable surface rust (it might be on the inner disc surface and not easily visible!) and then you drive the car normally still causing spot overheating.
Probability: A bit less common than #1, but still very popular and commonly underestimated
Common symptoms: Usually hardly noticeable juddering when cold and moderate one on hot brakes
Solution: Discs and pads replacement only. Also useful to reconsider a combination of discs+pads. Some claim that skimming can help but the areas of hardened steel go deep into the disc material, so it's a temporary fix not solving the core issue, and juddering always returns after a while.

3. Run-out is when the disc is not sitting perfectly perpendicular to the axis of wheel rotation. Can be caused by dirt and rust being introduced to the wheel hub face, brake disc face or wheel mounting face. Also happens when the wheel hub is damaged or the wheel is incorrectly mounted (not aligned perfectly with the hub or overtightened). It causes the brake caliper to vibrate transversely and also adds pressure pulsation to brake lines
Probability: The least common, usually this defect is immediately noticeable after carrying out certain works on the wheels and brakes or after hitting a large pothole (tyres and alloys usually take the damage first though)
Common symptoms: Severe judder regardless of the temperature
Solution: An immediate and thorough cleaning of all mounting surfaces during any works with wheels, removing all rust and debris, using copper grease on clean surfaces, using spigot rings for non-standard wheels, wheel nut tightening only with a torque wrench.


Worth noting that it is always recommended to make a comprehensive examination of the braking system whenever juddering is experienced and to find the root cause. Without doing so, there is a good chance you would see the same symptoms developing soon after replacing the discs.
 

·
Registered
Joined
·
29 Posts
Discussion Starter · #8 ·
Check to see if there are cracks around the drilled holes if they are oem discs.
I’ve checked for cracks and can’t see any. The holes were quite full of dust so have cleaned them out today and will take it out later to see if it has made any difference.

when they are cold they are fine, just get worse the hotter they get.
 

·
Vendor
Joined
·
8 Posts
Cracks as such are rarely causing issues.

As an example, Porsche specifies cracks up to 7mm long are not even considered to be a defect at all provided they do NOT connect the two drilled holes and do NOT reach the edge of a disc
267253
 

·
Registered
Joined
·
29 Posts
Discussion Starter · #10 ·
Decided to comment on the issue as I previously had a lot of experience with brake judder.

Actually, the matter is a tad more complicated than it might seem from the traditional point of view.
There are three major reasons for brake judder in decreasing order of probability:
1. Distortion
2. Thickness variation
3. Run-out


1. Distortion commonly happens when the disc is overheated or shock-cooled (think hitting a puddle of water during a spirited drive). Significant disc wear and brake pads inadequate for actual use can all contribute to overheating. Incorrect brakes warming and cooling procedures on a race track are also likely to cause this.
Probability: This is the #1 reason for a noticeable judder
Common symptoms: Juddering usually less severe when cold and very noticeable on hot brakes
Solution: Discs and pads replacement only

2. Thickness variation is caused by local spots of hardened disc material due to local overheating. It causes the brake pad to 'jump' resulting in judder.
Realistically, in most cases, this happens when pad material transfers either due to corrosion (example: car washed and parked without drying brakes) or static melting (example: you braked hard to a full stop and keep pressing the brake pedal to hold the car still). Local overheating can also easily happen after brake discs developed considerable surface rust (it might be on the inner disc surface and not easily visible!) and then you drive the car normally still causing spot overheating.
Probability: A bit less common than #1, but still very popular and commonly underestimated
Common symptoms: Usually hardly noticeable juddering when cold and moderate one on hot brakes
Solution: Discs and pads replacement only. Also useful to reconsider a combination of discs+pads. Some claim that skimming can help but the areas of hardened steel go deep into the disc material, so it's a temporary fix not solving the core issue, and juddering always returns after a while.

3. Run-out is when the disc is not sitting perfectly perpendicular to the axis of wheel rotation. Can be caused by dirt and rust being introduced to the wheel hub face, brake disc face or wheel mounting face. Also happens when the wheel hub is damaged or the wheel is incorrectly mounted (not aligned perfectly with the hub or overtightened). It causes the brake caliper to vibrate transversely and also adds pressure pulsation to brake lines
Probability: The least common, usually this defect is immediately noticeable after carrying out certain works on the wheels and brakes or after hitting a large pothole (tyres and alloys usually take the damage first though)
Common symptoms: Severe judder regardless of the temperature
Solution: An immediate and thorough cleaning of all mounting surfaces during any works with wheels, removing all rust and debris, using copper grease on clean surfaces, using spigot rings for non-standard wheels, wheel nut tightening only with a torque wrench.


Worth noting that it is always recommended to make a comprehensive examination of the braking system whenever juddering is experienced and to find the root cause. Without doing so, there is a good chance you would see the same symptoms developing soon after replacing the discs.
Thanks very much for taking the time with writing a very helpful description.

it’s strange becauseI only noticed it shortly after some new tyres were fitted however that wouldn’t allow for the dirt to get behind the discs because they were not removed. The day after the tyres were fitted the car was in Nisssan and I asked them to double check the torque of the nuts and he commented that they were all okay, just slightly under and so he done them to correct settings with a torque wrench so I doubt if the hub has been damaged through over tightening. There are no hot spots as far as I can see and no cracks. Never done a track day and never been driven hard for more than a few minutes at a time and never had then hot enough to get brake fade. When cold they are okay and when they warm up they get worse and can then start to feel like wheels are out of balance even when not braking.

Thanks again.
 

·
Vendor
Joined
·
8 Posts
Thanks very much for taking the time with writing a very helpful description.

it’s strange becauseI only noticed it shortly after some new tyres were fitted however that wouldn’t allow for the dirt to get behind the discs because they were not removed. The day after the tyres were fitted the car was in Nisssan and I asked them to double check the torque of the nuts and he commented that they were all okay, just slightly under and so he done them to correct settings with a torque wrench so I doubt if the hub has been damaged through over tightening. There are no hot spots as far as I can see and no cracks. Never done a track day and never been driven hard for more than a few minutes at a time and never had then hot enough to get brake fade. When cold they are okay and when they warm up they get worse and can then start to feel like wheels are out of balance even when not braking.

Thanks again.
It's an extremely important point that sometimes you feel the judder even when not touching the brake pedal and narrows down the searches.
I would suspect alloys/tyres first – either balancing issues or alloy/tyre distortion (perfectly visible when the wheel is rotating on a balancing stand, you will notice a wheel run-out). Please visit any reputable tyre shop and ask them to check both matters.
 

·
Registered
Joined
·
388 Posts
Another idea (from many years ago). I had a car where I could feel juddering through the brake pedal. It turned out to be one piston seized in a caliper and this was distorting the disk. I found out when I braked hard one day and the disk sheared off from what I believe is called the bell! Quite exciting at the time...
 

·
Registered
Joined
·
29 Posts
Discussion Starter · #13 ·
Thanks guys for the tips.

Took the car out to attempt to burn off any pad deposits and when cooling the brakes down the drivers front wouldn’t cool down and when pulling over to check the drivers front was so much hotter than the passenger side.

From that I’m going to guess there is a calliper problem and because the car is still under warranty then that should be covered. Because of the heat built up then I’m wondering if they should also replace the disk and pad as part for the warranty repair. Anyone idea or suggestions if they try and say they will only do the calliper?

thanks in advance
 

·
Premium Member
Joined
·
795 Posts
Get Nissan to check the brake discs and pads thoroughly. Assuming they were OK (including callipers) when they last serviced it then any damage to them now could be said to be directly caused by the sticking calliper piston, so for me, I'd want all parts that are damaged replaced. Wear and tear is one thing, but damage is another....that's the point I'd be making to them.
 

·
Registered
Joined
·
29 Posts
Discussion Starter · #15 ·
Get Nissan to check the brake discs and pads thoroughly. Assuming they were OK (including callipers) when they last serviced it then any damage to them now could be said to be directly caused by the sticking calliper piston, so for me, I'd want all parts that are damaged replaced. Wear and tear is one thing, but damage is another....that's the point I'd be making to them.
Good advice, thanks.
 
1 - 15 of 15 Posts
Top