Kawasaki Ninja 300 Forums banner
1 - 10 of 10 Posts

2 Posts
Discussion Starter · #1 ·
Hey guys, below is a photo of my rear brake calliper.

Does anyone have any ideas on what could be causing my right brake pad to wear out much, much faster than my left?

Automotive tire Bumper Hood Automotive exterior Motor vehicle

356 Posts
uneven brake pad wear is usually the result of a stuck slide pin or rusted (stuck) caliper piston. Have you taken your caliper off to inspect, clean and lube? Easy to do and smart preventative maintenance..especially if you ride a lot of miles or live where things get crusty and rusty.

84' Goldwing Aspencade, 91' EX500, 98' Ninja 250 w/ 17' 300 engine, 07 EX500
86 Posts
Those pistons don't look for sure, I assume the caliper has never been serviced. Slider pins not working properly.

I did a write-up about brakes a long time ago, here it is,

I recommend that every time you change your pads, you service the calipers, he's my write-up to help you out. It should fix your initial problem, and keep your calipers in top working order.

For those of you whom are scratching their heads, here you go,*

Front Caliper Service (also rear as well)

Many folks have posted here with a Varity of front brake problems.

*Many of which are attributable to the lack of proper maintenance.

*Here’s how you can always have a brake like when your bike was new.

A short list of the problems and the causes.

Soft lever or lever goes to the bar.

The usual cause is the pistons are pushed too far back into the caliper by a flexing a warped, coned, disc.

*Using up too much piston travel before the disc is pinched.

Juddering in sync with wheel rotation.

The disc is worn, and its thickness varies. *This causes the caliper to “sink” into the thin part and when the thick part comes around, it gets wedged into a smaller space causing a tightening of the brake. Then the tight spot passes through and it like the brake is released. Then repeat, repeat.

Cupped, coned, or warped disc.

Unfortunately this is a common problem with EX’s the cause is the disc is stretched in the center due to being rigidly bolted to the wheel. *The huge force of braking is transmitted to the wheel through the webbed center of the disc which gets stretched and becomes larger than the space it occupies in the center of the disc. This causes the center to push to the side trying to find room for itself.

*Resulting is a cone shaped disc.

Soft lever 2

The caliper has pistons only on one side, so as the pads wear the caliper must shift sideways apply even pressure on both sides of the disc.

*To allow this the caliper floats on two pins. *If these pins get dry (no grease) dirty or bent. The caliper won’t center itself and bends the disc to wherever it is.

This take up lever travel and when released pushes the pistons further back than necessary.

*If not fixed will eventually destroy the disc (warp it).

Ok how to prevent all of the above.

When new pad time comes around, resist the temptation to just pop in new one and go.

*Every time you must do these things.

Remove caliper disassemble and clean it.

Clean and re grease the sliding pins.

Polish the caliper pistons to remove dirt. If you just push the pistons back into the caliper leaks will result. Or binding.

Tools required:
12 mm socket
8mm open end wrench
3” or bigger C clamp
a supply of new bake fluid.
wire brush and or steel wool.

Remove the caliper from the fork leg but leave the brake line on.

Remove the old pads and the mounting frame (the sliding pins)

Remove the cover from the Master Cylinder on the Handel bar.

Attach the C clamp to one of the pistons but don’t squeeze it. *Pump the lever on the bar slowly to push out the other piston almost all the way. *Put the C clamp on that piston and push out the other one.

Remove both pistons by hand.

Remove all the rubber part from the caliper, the seals are in the grooves in the caliper and dull pointed thingy will get them out easy.

Disconnect the caliper from the brake line.

Soak all the rubber parts in new clean brake fluid * ONLY!!!!! * Rub them with you fingers till as clean as new.

The caliper can be cleaned with a wire brush or even a Moto tool for the internal grooves, NOW’s the time to paint it if you wish.

Polish the pistons till they are smooth and shinny. They are chrome plated. If any of the plating is chipped or damaged below the dust cap groove. *Replace it.

The master cylinder is the subject of another write up and we’ll assume it in good working order here.

If you suspect your disc is bad, your bets bet is to replace it with an after market one fro EBC or Galpher.

*Don’t remove the disc unless you intend to replace it. *It will assume a new shape if it is * stressed and will not be flat again. You can try to check its condition by placing a straight edge across the face of the pad swept area looking for any distortion.

Re assembly

Take the nice clean rubber seals and install them into the caliper then the Dust covers.
Wet all the rubber with new clean brake fluid and partially fill the caliper with new fluid.

Push the pistons though the dust seals and into the caliper body until the dust covers snap into the grooves.

Fill the MC with new fluid and pump the lever while holding the Line above the MC till clean fluid flows.

Connect the line to the caliper while holding it above the MC.

Pump the lever with the bleeder valve open till fluid flow from the bleeder.

*Hold the caliper so that the bleeder is the highest point.

Close the bleeder and pump more fluid into the caliper but don’t push the pistons all the way out.

Then squeeze the pistons all the way back in and install the new pads.

Re grease the slider pins and assemble the dust seals and re mount the caliper on the forks but leave the bolts loose.

Now clamp the caliper to the disc with the brake lever.

Look at the space between the fork lugs and the caliper, clamp and release a few times as you tighten the bolts by hand. It one lug touches much before the other the odds are you mounting bracket is bent. You can straighten it.

After you get it the best you can. Some shim washers made from alum can stock can be fitted to the loose side.

** *What we are doing here is trying to minimize the bedd in time and gets the best pad life.

Ok with everything tight you should be through, Notice we don’t need to bleed the brakes, but if you screwed up in any of the above steps, you might do that here.

Be careful to Bedd in the new pads gently.

*Too much pressure too soon will burn the pad material as only a small area will be gripping at first. You also won’t have full braking power till the pads are fully familiar with the disc

I also recommend flush and fill with new brake fluid, also I'd go with 5.1DOT.

No matter what kind of brake fluid you choose, always periodically flush and fill with new fluid.

This is the one I use


Also inspect the brake lines, replace is needed, http://faq.ninja250.org/wiki/Stainless_steel_brake_lines_upgrade

Venhill Introduction
Greetings everyone!

I wanted to take a moment to introduce you to Venhill...

Venhill manufactures some of the highest quality brake lines and cables you can get. We've been in business since 1971 and currently offer a full range of brake lines for the Ninja 250, first and second generations.

Our website, venhillusa.com, is setup to take orders for any year Ninja 250 as well as many other bikes. You can pick your bike and then customize your kits as you wish. We offer many different colors of hose as well as different finishes and materials for hardware. All of these options can be selected during the purchase process, so you'll be sure to get exactly what you want. You can even add length to hoses if needed.

To get an idea of our reputation, have a look at our eBay feedback.

If you have any questions or comments about Venhill products or brake lines or cables in general, please share them. I'm happy to be a resource for general information about brake lines and cables as well. Technical questions are welcome!

Please take a look at our website and let us know what you think. We just recently did a complete makeover and are interested in feedback. (venhillusa.com)

Have a great day and stay safe,

Venhill USA

For the detail oriented out there, some interesting things you might want to know about Venhill and our products:

Our factory is ISO 9001-2000 approved, which basically means we have the ability to consistently produce quality products. To qualify for ISO approval your factory and quality control mechanisms are evaluated as to whether your "good" products happen by chance, or if they are a result of good quality control.

All of our hoses are built to DOT/TUV spec and have been certified as such. We submitted hoses to the TUV (German DOT) for testing and only by passing are we allowed to use the TUV symbol on our hoses. Every hose we sell is built to these specifications, even if it is for track or offroad use only. It just makes for a higher quality product.

All of our hoses are hydraulically crimped, not hand crimped, and leak/pressure tested in a water bath. Yes, we immerse every hose we build in a water bath and pressurize it to check for leaks and to verify integrity of the crimps.

Venhill's hose core is authentic DuPont Teflon which is more expensive than generic "PTFE" but is stronger with a smoother inner bore. This is surrounded by 96 strands of braided marine grade stainless wire. 96 strands is more dense than some other braided line brands and the marine grade alloy is a stronger metal, which reduces expansion, the reason rubber hoses feel "spongy". Finally, we coat the braid with a UV-resistant PVC, extruded on during manufacture. This protects the hose as well as body and paint work.

Our hose design uses free-floating swivels, which allow you to loosely install everything before the hoses are tightened into place. This ensures the hose is not forced into a twist or kink when the banjo bolts are tightened. If you're worried about leaks, don't be. Our swivels work on the same premise as every threaded connection on a car or truck.

As you can see, we're sort of obsessed with quality and safety. We look at it this way: If we're asking you to put our brake lines on your bike, you're trusting us with the integrity of your brakes. That's a serious concept and we refuse to compromise when it comes to the integrity of your brakes.
I have these stainless steel lines on my Ninjette, and so far, some good, I recommend getting the stainless steel banjo bolts, I noticed my chrome ones have started to rust slightly, a good excuse for me to upgrade to titanium

On my 91 EX500 I have Spiegler, in orange to match that bike.

So you have made the decision that your OEM rubber lines need to be changed.

So why choose Spiegler Brake Lines?

A: Strength

That’s the short answer. But it doesn’t tell the whole story.

Spiegler Brake Lines strength comes from our innovation and research, materials and construction, knowledge and experience, service and support.

At Spiegler, we believe that the more you know about what we put into our products, the better you’ll be able to answer that question yourself.

That’s the short version; now let’s cover this topic more in depth.

Most OEM manufacturer recommend that you replace your rubber brake lines every 2 to 3 years. Why do the OEM’s recommend this? Over time OEM rubber lines deteriorate rapidly due to expansion and UV damage. This leads to increased braking distances and possible failure.

At Spiegler, our brake lines are made of only the finest materials available.

Outside casings are made of tightly woven stainless steel braiding that exceeds our competitors
The inside is made with DuPont’s PTFE-Teflon which eliminates expansion and adds durability
Crimp sleeves are made from stainless steel; competitors are using mostly carbon steel
Unique patented adjustable banjo fittings eliminate line twist during installation.
30% weight savings in comparison to other stainless steel braided brake lines
DOT approved
Lifetime warranty
117 color combinations possible which allows customers to personalize their bikes
We can build your lines to any specifications for custom applications
All brake line kits come ready for install

For more information on why you should choose Spiegler Brake Lines, you can view the following pages for a more detailed look into Spiegler brake lines.

When it comes to safety items like brakes, when in doubt, throw them out, it's your safety in your hands, and is cheaper than a visit to the ER.

Buy quality pads,I personally recommend EBC brand either the HH, or the Extreme HH.

EBC full floating rotor, replace the OEM rubber line with a stainless steel braided brake line, cheaper than replacing them with OEM.

On my 500 I have Spiegler line


On my Ninja 250 i went with Venhill


With all that, it will stop on a dime, and leave you nine cents in change.

look here http://ebcbrakes.com/products/motorcycle/

And also read this, http://www.ex-500.com/wiki/index.php?title=Rotors_and_Pads

That should answer any questions you might have.

84' Goldwing Aspencade, 91' EX500, 98' Ninja 250 w/ 17' 300 engine, 07 EX500
86 Posts
Nice write up, Ghost!
Thank you, it's been a long time in the making. I've been on motorcycle forums for a long time, anyone remember the BBS days of the internet?

It's common brake problems, too many threads to even count, so I did the write-up to save time, if followed correctly, no more issues hopefully.

I'm new to the Ninja 300, but not motorcycles, I thought I'd add it here, and I have it saved so I can copy and paste it when needed

Or someone could make it a sticky.
  • Like
Reactions: Topaz

464 Posts
Looks like it was already solved, but just to toss in my opinion, wear on the piston-side only points to stuck slide pins. Also possible the piston is sticking, making the brake drag and pads wear faster.
Cleaning and greasing the pins may be enough to solve the problem, but disassembling/cleaning/rebuilding the caliper couldn't hurt either.
I've also heard (though no direct experience myself) that the rear master cylinder often has problems with gunk building up around ports causing brakes to stick. Fluid replace with a good cleaning before refill may be helpful in that case.

Super Moderator
2,653 Posts
Thank you, it's been a long time in the making. I've been on motorcycle forums for a long time, anyone remember the BBS days of the internet?
I'm old enough to remember the BBS days!

Or someone could make it a sticky.
I can only sticky the first post in a thread. If you create a new post with the info, I'll be more than happy to make it a sticky.

84' Goldwing Aspencade, 91' EX500, 98' Ninja 250 w/ 17' 300 engine, 07 EX500
86 Posts
Wow! Incredible write up, super in-depth, thanks so much Ghostt!
I'm old enough to remember the BBS days!

I can only sticky the first post in a thread. If you create a new post with the info, I'll be more than happy to make it a sticky.
If you want I can DM or email you the file edited so it looks a little smoother on this forum and then put it wherever you want to I guess maintenance maybe troubleshooting up to you. Just let me know.

Super Moderator
2,653 Posts
If you want I can DM or email you the file edited so it looks a little smoother on this forum and then put it wherever you want to I guess maintenance maybe troubleshooting up to you. Just let me know.
If you want to DM it to me, then I can create a new post and get it up. Thanks for sharing your vast knowledge with the community!
1 - 10 of 10 Posts