Replacing EX500 front master cylinder/brake

[elaineo]

If I were to remove the front master cylinder and brake from an EX250, and put them on an EX500, would this be a good idea or a bad idea?

(i checked the part numbers on the EX250 and the EX500 and most of the part numbers are the same, except for some screws and crap)

[VinceF2]

If the numbers are the same then I don't see why there would be a problem... I also don't see what the benefit would be seeing how they are the same system Unless are your brakes busted now?

[stoinkythepig]

Might even be able to do it without opening any brake lines. If the parts fit and the bike stops normally, why not? Kawasakis use tons of common parts.

[VinceF2]

Originally posted by stoinkythepig
Might even be able to do it without opening any brake lines. If the parts fit and the bike stops normally, why not? Kawasakis use tons of common parts.

Ya and more so between the 250 and 500... I know the rear master cylinder is the same... even though the number differs slightly... although the 250 still runs a 16" wheel no? I don't know if that would change the caliper or not... hmmmm

[twrayinma]

Originally posted by VinceF2
although the 250 still runs a 16" wheel no? I don't know if that would change the caliper or not... hmmmm

wouldn't the caliper size be based more on the disc size, not the wheel size?

[stoinkythepig]

Not on these bikes. That caliper model is used in all kinds of applications.

[elaineo]

Actually when i posted this i meant to ask, how much trouble would it be.
The EX500 doesn't have a rear master cylinder (it's an 87 so it has drum brakes)
... but yeah the front brakes are pretty crappy right now.

i'm gonna try switching them tomorrow if i don't come back here, that probably means my bike wouldn't stop and i crashed on the highway

[stoinkythepig]

Originally posted by elaineo
Actually when i posted this i meant to ask, how much trouble would it be.
The EX500 doesn't have a rear master cylinder (it's an 87 so it has drum brakes)
... but yeah the front brakes are pretty crappy right now.

i'm gonna try switching them tomorrow if i don't come back here, that probably means my bike wouldn't stop and i crashed on the highway

Assuming it's a simple bolt on swap, the work should take 15 minutes. If you need to open the lines and bleed the brake afterward, may take a bit longer.

The "new" pads will not be matched and worn in to the old front disk so expect poor performance until the pads bed in.

Out of curiousity, what's "pretty crappy" feel like? If you get vibartion and pulsation when applying the brakes, the new master cylinder and caliper won't help at all.

[elaineo]

I think Honclfibr had already bled the brakes and changed the pads, but the front brake is still kind of bad.

i was just thinking of swapping out this stuff:

<img src="http://www.eecs.harvard.edu/~elaine/stuff/Image1.gif">


and this stuff:

<img src="http://www.eecs.harvard.edu/~elaine/stuff/Image2.gif">

Pretty crappy: there was no vibration or pulsation, but it just felt like the bike wasn't really stopping when I applied the brakes. not sure how else to describe it....

[Honclfibr]

Originally posted by elaineo
I think Honclfibr had already bled the brakes and changed the pads, but the front brake is still kind of bad.

Yep. When I bought the bike, the rotor was warped, so the rotors about 2 years old. The pads were changed about 100 miles ago, and the brakes were bled last weekend.

Pretty crappy: there was no vibration or pulsation, but it just felt like the bike wasn't really stopping when I applied the brakes. not sure how else to describe it....

It takes a lot of force on the lever to stop the bike. Like the master cylinder is not properly engaging the calipers? It's not spongy (anymore; since I bled the brakes), just requires a lot of force and you never feel like you're getting maximum braking force out of the caliper.

[stoinkythepig]

I'd try new pads (swap just the pads from the 250 first) before doing anything else. Any chance the bike had a recent fork seal problem? If the pads are coated in fork oil, they are shockingly bad at stopping the bike.

You ought to Brakleen, scrub, and re-Brakleen the whole assembly too. Some brake pad materials are incompatible and residue from the old pads can make the new pads feel like crap.

Does the bike by chance have a PFM iron front rotor? They suck.

[elaineo]

well that only took 4 hours and didn't even work

[stoinkythepig]

Originally posted by elaineo
well that only took 4 hours and didn't even work

Holy crap! 4 hours, I've installed an engine in less time than that. What happened and why doesn't it work?

[elaineo]

Originally posted by stoinkythepig
Holy crap! 4 hours, I've installed an engine in less time than that. What happened and why doesn't it work?

Hmm you should probably ask darrell, cuz clearly he knows WTF he's doing

....at this rate, it would probably be faster to just try to get the 250 running again

[Degsy]

If the master cylinder is not exactly the same size (volume of fluid-wise) then it will not work.

Elaine, speak to KMF re your bike woes.


derek

[elaineo]

Originally posted by Degsy

Elaine, speak to KMF re your bike woes.

hmm really? not to pass judgement or anything, but from what i've seen in the Pit Area he seems to be a little unfriendly and a total potty mouth. will do, though. thanks derek!

[Degsy]

Send him a pm.

derek

[Honclfibr]

Turns out the caliper from the EX250 didn't work on the EX500 for some reason. Which is odd because they had the same part number, but they looked slightly different; notably the bleed nipple was in different spots on the two.

Anyway, with a new caliper and a mityvac bleeder, they are stopping much better now.

[Stoneman]

Haven't you learned your lesson letting Darrell work on your bike yet???

I'd be concerned the thing would explode when ya squeeze the lever...

[Honclfibr]

Originally posted by Stoneman
Haven't you learned your lesson letting Darrell work on your bike yet???

I'd be concerned the thing would explode when ya squeeze the lever...

Damn man, what is it with you and resurrecting dead threads just to pick on me?

Anyway, the bike did NOT explode, the brakes were working properly right up until wednesday, and unless some bike thief with poor taste in motorcycles has decided to yank it from it's cambridge home in the last 4 days, the bike is just fine

Though, I'm thinking we should have parted it out and carried it down to P.R. in our luggage, as renting bikes here turned out to be an impossibility despite all our best efforts. The only place to rent them is from Ducati Puerto Rico, they want $150 a day (for your choice of a monster, ST, or ST4), a $1500 deposit, and they absolutely positively won't rent to you unless you're 25. Which neither of us is Too bad, as they've got some pretty sweet roads. Although, it rains all the time and noone here can drive for shit, so I suppose the bike thing was a bad idea.

Hey what's the deal with gas during trackday? If we ride up the night before with just what's in our tanks, is it gonna be a big deal to buy gas at/near the track?

My cat's breath smells like catfood.