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Severe pulsating with new EBC rotors and pads

D

ddialogue

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Guest
My apologies in advance for yet another brake pulsating thread!  ;D

My 2010 C14 has had pulsating in the brakes since I bought it used in 2012 with 2,750 miles on it.  It's gotten progressively worse so I broke down and bought a new set of EBC MD4155XC's and the matching EBC sintered brake pads.  These things look great on the bike and I was excited to take it for a test spin.  Once out on the roads I noticed the pulsation is now twice as bad as with the worn out stock rotors.  It's completely unrideable and I'm at a loss as to why they'd be like this.  :truce:  I'm going to go through the entire front end tomorrow to ensure cleanliness of the components and that everything is torqued to spec.  While replacing the pads, I did notice the right caliper pads were worn about twice as much as the pads on the left caliper but I didn't really think too much about it.

Thoughts?

Thanks,
Dave
 
Put your bike on the center stand and jack it up so the front wheel is off the ground. Without applying any brake pressure spin the wheel. Are the brakes dragging ? If yes you have a caliper/master cylinder problem. One of the likely culprits is the return hole in the master cyl. How old is the brake fluid? Is it clear or dark? Are the wheel bearings ok?
 
Check the runout or the rotors with a runout gauge.  It's possible you installed the new rotors without getting the mating surface on the hub perfectly cleaned. 
 
jwh20 said:
Check the runout or the rotors with a runout gauge.  It's possible you installed the new rotors without getting the mating surface on the hub perfectly cleaned.
Click to expand...

Thank you both for your replies.  I stopped out this morning and bought a gauge to check the run-out.  Man, they are WAY out for brand new rotors.  I pulled the wheel and made sure the mating surfaces were clean (they looked good but I cleaned them again.)  I cleaned the red loc-tite out of the recessed bolt holes thinking that maybe the bolts weren't going in deep enough before hitting their torque values.  Put it all back together and the result is the same.

I'm including a link to videos of the rotors with the gauge on them for your viewing pleasure.  I appreciate any and all thoughts on the problem.  Thanks!

https://www.dropbox.com/sh/3ph30xz8tg5u65o/AAAGoRGy-RzcwISTuiobKKzOa?dl=0
 
Per Kawi Service Manual::

Brake Disc Warp Inspection
• Raise the front/rear wheel off the ground.
Special Tools - Jack: 57001-1238
○For front disc inspection, turn the handlebar fully to one
side.
• Set up a dial gauge against the disc [A] as shown and
measure disc runout, while turning the wheel by hand.
If runout exceeds the service limit, replace the disc.
Disc Runout
Standard: TIR 0.15 mm (0.006 in.) or less
Service Limit: TIR 0.3 mm (0.01 in.)
 
Your new rotors don't look that bad.  The small variation you're measuring is likely due to the mounting surface on the hub.  I would not expect what you've shown to cause pulsing in the lever.  I've found that pulsing is most often caused by THICKNESS variation in the disk.  Thickness is usually hard to measure accurately due to wear grooves on used disks, but should be easy on your new ones.  I don't see a value listed for that in the service manual, but as best I can remember it should be well below .001 variation around the braking surface, probably more like .0005 variation from max to min.  You'll need a good micrometer to check that. 

Another possible cause, especially on new disks is oil or preservative left on the surfaces by manufacturing processing.  I'd try cleaning both sides of the rotors very carefully and see if that helps.
 
A few Thoughts:

Double check wheel and steering bearings

How is the rear rotor? Because of the linked brakes, you could be feeling some rear brake action?

Get rid of any "red" Loctite on any small bolt like that going into aluminum.
The factory had a "pink" Loctite on there. "Red" is way too excessive to use on anything going into aluminum unless you use heat and clean all of it out of threads. Red is designed for permanently holding bearings/bushings that are not readily dis-assembled
 
noticed the pulsation is now twice as bad as with the worn out stock rotors.

Possibly brake pistons sticking causing drag and rotor deflection to one side, building heat and vibration.
Fork alignment off. loosen the pinch bolts block the tire bounce the forks 5 or 6 times, tighten right then left.

A couple thoughts.
 
At this point I'd go back to the basics. Check the master cylinder and calipers for proper function. If the disc's are ok that's all that's left.
 
Something to check:

I replaced my OEM rotors with the Chinese rotors they sell on eBay and used EBC pads. The result was VERY bad pulsing- dangerously so. I found out the rotors- although very nice machining, had a hub that was I estimate to be 3mm thicker than OEM and it was actually hitting my ABS sensor during braking. Take a look at your sensor, does it look like it was a scoured with sandpaper or have scratches of any kind? Anyway, I was able to shim the ABS sensor back with 2 washers, which took away 85/90% of the pulsation...it's still there, but livable.
 
Thank you all for your responses and suggestions.  I spent most of Saturday mounting, torquing, adjusting and checking the setup of the rotors but in the end it was to no avail as the rotors are still .005" and .003" out and the shudder under braking is severe.  :mad:

I emailed EBC Customer Service with links to the videos and asked them for suggestions.  EBC replied asking for my mailing address so they can send warranty replacements.  I'll update this thread with the results once the warranty replacements are on.  Thanks.
 
**UPDATE**

After EBC reached out to me, they sent me a set of warranty replacement rotors (which arrived two days after they contacted me.)  They also included a full set of replacement brake pads!  Woot!

While I had the wheel off again, I cleaned and replaced all the seals in the front calipers as well as installed a set of Speed Bleeders all the way around.  I'm happy to report that braking is very smooth now and I'm a very happy camper!  So, the first set of rotors I received must have been bad from the factory.

Now to figure out why my front brake is squishy... :)

Thanks all!
 
Excellent, drive me nuts when something isn't right on my motorcycle. Good to know EBC responded so quickly.  :great:
 
Hi,
      Glad you came out of this ok, and good on EBC, but.... :great:

I can't help but wonder what was wrong with the Rotors if the run out was in spec??? :eek:

Seems, EBC knew something, though??? ;D ;D ;D
 

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ddialogue said:
**UPDATE**

After EBC reached out to me, they sent me a set of warranty replacement rotors (which arrived two days after they contacted me.)  They also included a full set of replacement brake pads!  Woot!

While I had the wheel off again, I cleaned and replaced all the seals in the front calipers as well as installed a set of Speed Bleeders all the way around.  I'm happy to report that braking is very smooth now and I'm a very happy camper!  So, the first set of rotors I received must have been bad from the factory.

Now to figure out why my front brake is squishy... :)
 

This is great news!! EBC came through on this. Good on them.
Squishy you say?
  You have to revisit youre bleeding method. My vote is there still some air in the system.
Thanks all!
Click to expand...
 
I see this thread was from some time ago, but, I just bought a 2013 C-14 with 13,000 miles from the first owner who bought it new in the showroom in 2015. He is a car restorer and meticulous about clean, well maintained vehicles. the bike is amazing. When I took it for a test ride, all was as I expected. This is my 3rd C14. Previously owned a 09, and an 11. When I applied brake, either front or rear or both, I noticed a chattering or pulsating. I asked him about it and he even rode it again and said it felt the same way it always had since he bought it. I know you cant trust everyone , but i trust this guy. So I bought it seeing how clean it was and could tell he was a clean/maintenance freak.

My other 2 C-14's were very smooth on the brake, there is definitely something wrong here. After reading this thread, it sounds like to me, that the rotors may have been wrong from the get go? Can they warp from just sitting too long ? maybe on the kickstand?

I guess my question is, should I change out rotors first, to eliminate that option. Is there much chance of some sort of malfunction with the ABS causing the pulsating?

Thanks for any advice.
 
No. If it's happening under low to moderate braking it's not the ABS activating, nor causing it.

If from day 1 as he says it may have been damaged during 2-3 yeas of storage somehow. Or it may have a flawed disc. l had one on my current used 14 when l got it (I've had 3 too) A disc had a thin area which was the cause of pulsing in the lever.

It can also be a warped disc obviously, or dark 'crud' burnished onto the surfaces, which I have also had on my three 14s. The latter can be effectively cleaned by sand/glass blasting the faces, tho others say they have done so by others more simple means but not my luck.

To check for the other two causes you need a magnetic base dial gauge, a fairly large piece of iron to stick it on and a strap to secure the bars hard against the stops L & R. With the wheel off the ground, use the strap to hold the bars against the stop very firmly, place the dial gauge mounted on the heavy iron so the the gauge needle just touches the edge of a petal and set the gauge to zero. Without rocking the bike slowly and carefully rotate the wheel 1 petal at a time and note the readings all way round. Repeat on other disc and chech results to specs.

A thin or high area can be found by turning the wheel by hand and marking it where it binds or frees when passing thru the pads, then using a micrometer to compare thickness here and there. I have had a disc ground flat by a brake specialist to fix it and yet still within min thickness spec. It was apparently flawed from new.

But changing the discs should fix it.
 
Last edited:
Ok so i have cleaned the grommets that allow the front rotors to “float”. I did this after watching a couple you tube videos that claimed it fixed the pulsating braked. I sprayed them with WD40 and was careful to clean the rotors with brake cleaner afterward . I did this twice, seperated by a weeks time. Each time I immediately had perfectly smooth brakes with no vibration at all. However they were still very “wet” if you will, for about 20-30 miles as the lubricants burned off. It seems like as the brake grip returned, the pulsating returned with it. Has anyone ever seen this . Im hoping it means perhaps i don't need rotors, but could use some pads . The bike only has 13 k on it but im sure they are the original kawasaki pads .
 
I had an issue with pulsing front brakes. I put a run-out meter on them and they both showed as being in spec, so I put on new pads and spun the grommets/buttons, but this did not help. I was told rebuilding the brake calipers would solve the issue, so did that. Did not help. So finally broke down and spent the money for new EBC rotors and pads. Problem fixed. Not sure if I had a warped rotor or just had a "hot spot" on one of them. Was suggested that bead blasting the rotors may have fixed the issue, but I was tired of messing with them. So that is my experience.

Steve
 
Was suggested that bead blasting the rotors may have fixed the issue...

It works for me. I have to do it almost yearly.
 
Im still curious, why would there be no vibration after getting wd 40 on the rotors and then as it burns off, the vibration comes back . Would that not suggest that the rotars ok and there is an issus withe pads, is there something else at play that I am obviously not qualified to understand ?
 
Bead blasting is worth a try before replacing the rotors, as it will certainly be a less expensive option. I got my rotors and pads from Murph's. You would have to investigate if anyone does that nearby where you live. I am also sure you could simply ship the rotors to someone who would blast them for you. So you have options if you think your rotors are not warped before spending the $500 on rotors and pads. Some guys will buy the cheaper Chinese rotors, but I am not a fan of buying Chinese unless it is the absolute only option.
 
jwstarkel3099 said:
Freddy where does one get bead blasting done , or did you buy the equipment?
Click to expand...
I get it done at the local cylinder head & eng recon worshop.

On mine it is apparently caused by pad material sticking to the discs randomly. This was actually identified by mother Kaw soon after the ZG14 hit the market. They said it was caused by the discs not getting hot enough to self clean like the ZX14 (which had the very same brakes) but riders rode them hard unlike old grannies like me. Many sets of early discs were replaced under warranty due to shudder on the ZG (3 on mine) but not the ZX. Kaw made slight changes to disc width and pad materials to mostly overcome the issue.
 
Very helpful info . I suppose its worth trying the blasting first. Thanks for the insight

Love this forum!
 
By the way, if i do get them blasted. Sould also put new pads on? There is only 13j on the bike but it is 10 years old
 
Yes, I would put new pads on, as your rotor surface will be fresh and you want to seat the new pads.
You can get OEM pads, I always thought they worked well
 
Hello all, just reporting in on my brakes. I have watched tons of youtube videos and of course several forum posts. After cleaning the rotor buttons twice, then sanding them twice, nothing worked. I finally put new rotors and pads from Murphs kits and the brakes are as smooth as butter. No more pulsating!!!
 
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