Rear Brake Help?

[tbo27]

So I just bought my fist bike, a 2001 Ninja 250. And I love it. The only real problem with it is that the rear brake doesn't work. I'm hoping someone here can help me figure out what's going on.

Basically, the brake pad is worn but not completely gone (should still work). However, when I press on the brake pedal, the pad moves toward the rotor like it should, it simply just doesn't touch it. Even with the brake pedal fully depressed, it does nothing because there's no contact between the pad and the rotor. The rotor is also very rusted, so I'm guessing the bike has had this problem for a while.

I took it to a shop and the guy said he wasn't sure what the problem was, but that it would cost me 200 bucks to fix it (with new brake pads installed as well). That seems like a steep cost so I wanted to see if anyone else has either had this same problem, or might know what's causing it so I could possibly fix it myself.

Any help's appreciated!

Tim

[2WheelGuy]

Put in new pads AND bleed the brake fluid THEN try adjusting the brake rod #43010.

http://fiche.ronayers.com/Index.cfm/...aster_Cylinder

[g21-30]

Replace the caliper with a working used one for under $25

http://cgi.ebay.com/ebaymotors/2001-...Q5fAccessories

Buy some new pads, install them and replace the caliper. Bleed the brakes and you're done for under $50!

Oh, yeah, the problem that you probably have is one or two frozen caliper pistons.

[tbo27]

Okay, just bled the brakes. Definitely needed to be done, but didn't really help the problem.

Are you sure it's the caliper? Everything looks like it's working just fine down there... the caliper moves towards the rotor and everything. It's just not braking at all.

And I don't know a whole lot about the mechanics of this stuff yet, just wanna make sure that's your best guess before I spend any money. Could it even be just that the brake pads are so worn down that they aren't touching the rotor?

Thanks for the quick replies.

[kkim]

Originally Posted by tbo27

Could it even be just that the brake pads are so worn down that they aren't touching the rotor?

no

[tbo27]

Originally Posted by kkim

no

Thanks.

Anybody else?

[HotWheels]

I think that caliper might need replacing as well. The replacement thickness of brake pads for the 250 is 2mm. I am not sure where you are at currently on those pads. Your sure you got call of the air out of the system as well right? Sometimes tapping the brake line and caliper will produce more bubbles being released. If that doesn't help then a replacement caliper is in order then. As shown by another post, eBay is your friend =) Make sure to buy new pads and follow the bed in procedure per the packaging. If the rotor is ridiculously rusted then a used rotor in decent condition via eBay may be in order as well. If it is only crusted some or a little bit then ride it and it will go away and be fine. Take care.

Since your new to bikes here is a guide on different kind of brake pads to consider and composits also

Deciding on composition

When it comes time to replace your brake pads, there are several choices for the EX250. There is one most popular choice on the 250 board, however, and that is EBC. EBC is also, not coincidentally, the easiest brand to find. There are some rider comments at the end of this article on EBC and SBS pads.

The first thing you have to do when you look for new brake pads is to decide what composition you want them to have. There are two basic categories: sintered metal, and kevlar/organic/semi-metallic/ceramic (lumped together as "standard" or "organic"). All new bikes have sintered metal pads front and rear from the factory. Sintereds have better stopping power and less fade than other kinds of pads, so that is naturally what is recommended for the front pads. You do not want to put anything other than sintered metal pads on the front of your bike.

The rear, however, may involve more personal preference and riding style. Most people, especially for the EX250, probably don't need or want sintered pads in the rear. The bike's tendency to lock the rear is well-documented. The aftermarket pads that we recommend here are all going to have more stopping power than the stockers (Galfer Blacks excepted). You'll have to decide what will be the safest combination for you. You'll still be able to stop just fine with organic brakes out back; if you ride really hard and use your rear brake a lot, you may be a candidate for sintered rear pads. If you are like some riders and are really easy on your rear brake, getting over 50,000 miles out of the original pads, you probably don't need sintereds.

Bedding-in the pads: Before you ride the bike really hard, you have to bed your pads to the rotors. Wash the rotors (Water Only, no chemicals or cleaners on them). Then, pay careful attention to the bed-in instructions that came with the pads. They're different for different pad compounds/companies, and what works best for pad X may not necessarily be best for pad Y.

A note on friction ratings: Brake pads are tested, then rated according to the amount of friction they provide. (This is the condensed version). The pads in this survey go from a rating of 'G' for the Galfer Black to HH. The higher the letter, the more friction they provide. In other words, Galfer Greens, at GG, will stop better than the Blacks, but aren't as strong as the HH Sintered. You usually only see companies displaying this rating on their top-end pads, the sintered "HH". Many times you won't see it listed. In general, most Standard pads are GG, and most Sintereds are HH.

For '86-87 models please click.
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Brake pad companies

Note: The dealers listed next to some of the part numbers are shown as a convenience to you. For some of these pads, it is a virtual impossibility to find them online. You will have better luck with your local shops. EBCs are everywhere; it's the others that take some research, and we thought we would share our findings.
[edit]
Kawasaki

If you've been running the stock pads and feel comfortable with them and don't need an upgrade, you can certainly put OEM's back on. Be aware that most aftermarket pads (excepting DP) are somewhat cheaper. OEM pads, for front and rear, are $81 shipped from Ron Ayers. You can always check with your local dealer, too. They will sell Kawasaki and, most likely, other brands.

Stock Part #'s:

Front: 43082-1068
Rear: 43082-1145
[edit]
SBS Brakes

SBS brakes are available, and pretty popular (see below), for the Ninja, but they are somewhat difficult to find online. Your best bet is to either check your local dealer, or go to Parts Unlimited, find their Dealer Locator, and have one of the dealers that comes up order them for you from the Parts Unlimited Street Catalog.

Part #'s:

Front StreetExcel Sintered: SBS 597HS
Rear Street Ceramic: SBS 615LF

You want the High Friction ('H' in part #) option for the front (HS, not HF) and the Low Friction ('L' in the part #) for the rear.

Dennis Kirk Part #'s:

Front StreetExcel Sintered: 192054
Rear Street Ceramic: 191060

Dennis Kirk doesn't reference these part #'s specifically for the EX250, but you can check against the manufacturer's number to make sure you're getting the right part. Ordering by Dennis Kirk part # is the easiest way to find your brake pads. The rear ceramic may be labeled "615LFS"; disregard the "S" in the number. It's just a packaging code.
[edit]
Ferodo Brakes

Ferodo has been a top brake manufacturer for a century. They deal with many race teams in the US and Canada, but also make street-oriented pads. They have indicated to the FAQ staff that, if you can't find a local dealer that can get Ferodo pads, then you can source them directly from their N American distributor, Brake Tech.

Part #'s:

Front SinterGrip ST: FDB481ST
Rear Platinum organic: FDB508P
[edit]
Vesrah Brakes

A Japanese company that offers a quality, inexpensive alternative to OEM. Vesrah custom-compounds their pads for different-sized bikes and riding conditions.

Part #'s:

Front Sintered: VD427JL
Rear Kevlar/Standard: VD430
Rear Sintered: VD430JL

Front & Rear Sintered at repairmanual.com (Scroll down)

Dennis Kirk Part #'s:

Front Sintered: 193088
Rear Standard: 191933
Rear Sintered: 195606

Dennis Kirk's cross-reference may not include the EX250. Order by part #. As long as the part # is right, you're set. They list their # and the manufacturer's part # side by side.
[edit]
DP Brakes

DP Brakes was previously a division of Dunlop Aviation. Dunlop invented the disc brake, originally for airplanes, and developed sintered metal technology as a tool for ever-heavier aircraft to be able to stop in wet conditions. Unfortunately, we don't get their best street pad, the DP "Sport", for the EX250. What we get is the DP Standard, which is, according to their website, "GG friction rated and made with DP Brakes' proven sintered metal material. An excellent replacement pad for touring and street machines where pad durability is the main concern." If your riding is mostly commuting, this could be the pad for you. This should also be a good choice if you want a sintered pad that doesn't grab as much as the HH pads.

Part #'s:

Front Sintered "Standard": DP 314 (Dennis Kirk #191617)
Rear Sintered "Standard": DP 316 (Dennis Kirk #191619)
[edit]
Galfer Brakes

Galfers come in a variety of compounds, and are sold under different names.

* The Galfer Black is also called "1052/1054" or "Carbon Semi-Metallic". This is a G-rated pad, for the rear only.
* The Galfer Green is rated GG, and is called "G1532" or "Kevlar-Ceramic". Also for the rear only, as Kevlars are not that great in the rain.
* Galfer HH is known as "Sintered Advanced Ceramic". Sintered brakes on the front, of course. Rear is your choice.
* The best explanation of the various Galfer compounds is on the CycleBrakes site.

At least part #'s are easy. You choose the base part number, then specify which compound you want. Front is: FD 090 / Rear: FD 104

All compositions at cyclebrakes.com

Front Sintered & Rear Black at Bike Bandit
[edit]
EBC Brakes

This brings us to the big boys. EBCs are available everywhere. They're by far the most popular replacement choice for club members.

Part #'s:

Front Sintered: FA 129HH
Rear Organic Kevlar: FA 141
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Comments and opinions
[edit]
EBC

* The biggest thing I notice with the EBC HH pads is that I get more "gritty" feel from the rotors, through the lever. It feels more like I'm scrubbing the rotors with 220 grit sand paper, as opposed to a fairly smooth brake pad. Personally, I like it. It gives me more feel of how much pressure I'm applying at the rotor.

They seem to have more initial bite. I suppose that they aren't as progressive as the other sets of pads, in that it takes less lever travel to create the same braking effect. There aren't any sharp spikes in the drag coefficient, though. The pads just seem to do a better job at turning pressure into friction, and hence into slowing power.

* EBC HH pads are quite different from the stock pads. Initial bite is stronger; at the first touch of the brakes you get quite a bit more stopping power. From there to about 70% lever pressure it is a similar feel to the stock brakes, but stronger. At 70% these pads really kick in and want you to stop RIGHT NOW.

I was doing about 20mph down a road and gave the brakes a strong pull up to 75% power. The front bottomed out and the tire lost traction. I have .90kg RaceTech springs, too!

The old FAQ is correct that these are excellent brakes if you want to brake late and hard. I often do this in our twisty Northern California mountains.

* I ran the sintered EBC front with kevlar rear. They were installed at a local fix-your-bike meet, and the shop guy wanted to put the kevlar on the front. The crowd of bikers looking on began to protest, so he switched to the sintered pads I brought. The kevlars are soft, with good feel, while the sintered pads are firm and grip well, even on a long downhill chicane, although they might squeal a bit. You want the good feel out back so you don't lock up the rear. Up front it's not such an issue.

* Kevlar/organic pads are very soft, and don't have good bite; this makes them great for rear brakes, but poor for the front. Also, they don't last as long as a nice sintered-metal pad. I like the idea of HH up front, and Blacks/organics on the back. It's already too easy to lock up the rear brake.

[edit]
SBS

* I run SBS sintered pads up front and ceramics on the back end. I am EXTREMELY hard on brakes, and find their longevity satisfactory. This configuration lasts about 80% as long as stock, but is half the price. I didn't like SBS ceramics on the front end, though; they weren't as effective in the rain and didn't "bite" as well as the sintered pads.

* I've run through the stock pads, SBS Ceramics and SBS Sintered Metallic. I found that the SM pads seem to work best in the rain, and are ideal for the front. The rear gets ceramics from now on. I like the progressive nature of the bite (very easy to only apply a "hair" of brake if so desired, but max braking is still very easy).

* I would run SBS over stock any day. They're good pads. I use SBS sintered metals in the front, ceramics in the back. They have really good bite, and I haven't noticed much (if any) fade.

[tbo27]

Figured it out. Here's what it was, for future reference if anyone else has this stupid problem...

First I bled the brake lines, which needed to be done. Didn't help though.

Then today I went and got new pads. I took off the caliper and noticed that the smaller pad looked kinda funny. Turns out it was not completely in the grooves that are on the caliper plate. So the small pad was not compressing like it should have been, it was just kinda staying put and not letting the pistons do their job. The pads were just fine and not even worn enough to be changed at all. But by this point my dumbass had already opened the new pads, so I just replaced them anyway.

Anyways, I cleaned everything up and put the caliper back on, and everythings working good as new. I appreciate the help though from everyone, kinda embarassing that it was this simple of a problem. Oh well.

Thanks guys