Brakes -demystified.

**FROSTY:Me** · 5th December 2008, 11:42

Folks theres been a lot of yak about brakes and a lot of people scared to work on them. They are definitely not something you can afford to have fail EVER.
When asked advice about playing with brakes usually my response has been--If you need to ask this question then take it so someone to fix.

But non Abs brakes aren't overly complicated bits of kit.
You squeeze the lever. That pushes a piston up top. Because fluid doesn't (as a rule ) compress, the brake fluid travels down the line,then pushes the caliper piston out and this pushes the brake pad against the disk which stops the bike--easy as really innit??
All the hard brain work has already been done my messrs Tokkico,Nissan ,Brembo etc.
So as long as you don't go thinking--"i know better than a manufacturer thats been building brakes for 50 odd years you can't really go wrong.PROVIDED you are competent.

When brakes deteriorate its usually due to a combination of crud buildup and with plain old fashioned wear and tear.
As a baseline we assume that the disks are clean and that the pads are in good condition and not hooking up on the calipers.
The first area I'd be looking at is making sure the brake fluid is new or nearly new. If not this is a great chance to replace it with new stuff.
Then I'd be ;looking at the brake pistons for crud/rust buildup.
I'd be looking at the slides for wear as well as ridges on the pad retaining pins. (if applicable)
Crud does build up behind the piston seals--this all needs to be got rid of .

Danger areas are--Using oil based lubricants on or able to go on any brake seals. Pushing pistons back in incorrectly and taking a bite out of a seal. Of Course Incorrect reassembily of parts. Golden rule i use is to do one at a time

Work In progress--bear with.

**Sully60** · 5th December 2008, 12:00

Gee, I hope you remember where you've put the hydraulic seals during your brake from this work in progress.

**slimjim** · 5th December 2008, 12:37

Frosty.....most of these bike rider's...."are not old school " ...and yes i'll say........... get them checked as per your normal bike service.........and please be aware.....you need to "speak and tell them " you wish for brakes to be checked ... you don't ask...they will not check them..

**Dargor** · 20th December 2008, 00:59

Originally Posted by slimjim

Frosty.....most of these bike rider's...."are not old school " ...and yes i'll say........... get them checked as per your normal bike service.........and please be aware.....you need to "speak and tell them " you wish for brakes to be checked ... you don't ask...they will not check them..

Dont know what school you go too, but i for one like doing stuff myself and informative posts.

**imdying** · 20th December 2008, 12:19

Originally Posted by slimjim

Frosty.....most of these bike rider's...."are not old school " ...and yes i'll say........... get them checked as per your normal bike service.........and please be aware.....you need to "speak and tell them " you wish for brakes to be checked ... you don't ask...they will not check them..

What's your point? You mean they won't try to maori them up with number 8? Seen plenty of old guys working on their brakes, can't say I've been very impressed with the "old school"

**Ixion** · 20th December 2008, 12:57

Don't mention bloody hydraulics to me. Damn perverse pain in the neck.

What was wrong with a good old fashioned cable ? Simple, effective, and if it wore or broke all you had to do was replace it. And they either worked or didn't. None of this "I'll work until things get a bit warm and then I won't" stuff.

"Change the brake fluid " ?

Oh, sure. Four little words that open into such a world of vexation. Bleed the brakes? I wish I could get hold of the bugger that invented hydraulics, I'd make him bleed.

**Ocean1** · 20th December 2008, 13:12

Originally Posted by Ixion

What was wrong with a good old fashioned cable ?

Cable?!!

Fookin' luxury.

When I were a nipper we used to nail bits of old aquajet to our boots.

When we could afford boots.

Fookin' yoof nowadays.

**martybabe** · 20th December 2008, 13:36

Originally Posted by Ocean1

Cable?!!

Fookin' luxury.

When I were a nipper we used to nail bits of old aquajet to our boots.

When we could afford boots.

Fookin' yoof nowadays.

Boots?!!!

Fookin' luxury

I used to nail mom's scones to my bare feet, Didn't stop to well but emergency braking smelt like a bakery on fire, Yum.

Yoof these days

**Motu** · 20th December 2008, 23:15

Originally Posted by Ixion

"Change the brake fluid " ?

Oh, sure. Four little words that open into such a world of vexation. Bleed the brakes? I wish I could get hold of the bugger that invented hydraulics, I'd make him bleed.

I changed the fluid in the BMW a couple of weeks ago - no problems at all.So how come Japanese bikes are such a pain to bleed hydraulics on? I've been bleeding brakes for decades,the only ones that give trouble are Japanese bikes....Japanese cars are fine.

**xwhatsit** · 21st December 2008, 00:36

Originally Posted by Ixion

Don't mention bloody hydraulics to me. Damn perverse pain in the neck.

Oh good, it's been a while since I upset Imdying.

Any force over that which is needed to make it break traction is wasted. If you have n ft/lbs of torque produced by a bike but 0.25 x n ft lbs is all that's needed to induce wheelspin, then you're wasting 0.75 x n ft lbs. Same thing with brakes -- if you can lock the front wheel with a cable-pull TLS drum, why invest all this extra hassle and expense in a bling-bling disc setup, which, in the end, seizes up in winter and feels like hydraulic-y rubbish when you pull the lever? That is, unless you're Rossi whirling around a race-track and you need to nail the brakes again and again from high speed.

**Sully60** · 21st December 2008, 09:37

Originally Posted by Ixion

What was wrong with a good old fashioned cable ? Simple, effective, and if it wore or broke all you had to do was replace it. And they either worked or didn't. None of this "I'll work until things get a bit warm and then I won't" stuff.

Originally Posted by Ocean1

Cable?!!

Fookin' luxury.

When I were a nipper we used to nail bits of old aquajet to our boots.

When we could afford boots.

Fookin' yoof nowadays.

Originally Posted by martybabe

Boots?!!!

Fookin' luxury

I used to nail mom's scones to my bare feet, Didn't stop to well but emergency braking smelt like a bakery on fire, Yum.

Yoof these days

Originally Posted by xwhatsit

Same thing with brakes -- if you can lock the front wheel with a cable-pull TLS drum,

You guys really seem to have a thing about these "brakes" you speak of!

My first race bike The lever on the right handle bar was just there to set your forearm to the correct counter steering angle, nothing else.
And the rear brake pedal was a more effective retardation tool than the drum itself, only on right hand corners though

**Pussy** · 21st December 2008, 10:19

Originally Posted by Motu

I changed the fluid in the BMW a couple of weeks ago - no problems at all.So how come Japanese bikes are such a pain to bleed hydraulics on? I've been bleeding brakes for decades,the only ones that give trouble are Japanese bikes....Japanese cars are fine.

The WORST brakes I ever had the displeasure of bleeding were on my TX650 Yamaha. They had the single two piston caliper. The ONLY way I could get the job done was by back bleeding.... until I worked that out I was certain I would never have a front brake on that bike again. No amount of trying to get pressure from the master cylinder down worked

**Ocean1** · 21st December 2008, 13:08

Originally Posted by Sully60

My first race bike...

CG125? 5"sls front?

Extravagantly opulent. The pinnacle of all things deceleration, naught wrong wiv it.

My first bike's brakes consisted of a pair of pliers with a cable through the handles, around the back sprocket, with mebe a square inch of pad riveted to the jaws. Seriously.

I had a 250 James that would have been catastrophically dangerous due to the cam locking up at full stomp, except that you could hardly tell they were on. Tried everything, eventually bunged the hub from a honda dream (I think) on it. Remember having to extend the spoke threads heaps 'cause I couldn't find spokes to suit...

**Ixion** · 21st December 2008, 17:37

Originally Posted by Motu

I changed the fluid in the BMW a couple of weeks ago - no problems at all.So how come Japanese bikes are such a pain to bleed hydraulics on? I've been bleeding brakes for decades,the only ones that give trouble are Japanese bikes....Japanese cars are fine.

Harrumph. This *was* on a BMW. The Suzuki was no problem .Once I wised up and tossed the fancy "one man bleeder" gadget I'd foolishly bought into the rubbish tin and went back to my faithful bit of of plastic hose wiv a nut on the and a jam jar of brake fluid.

But no way was the BMW going to relinguish the air out its system until I shoved a horse syringe up its arse. That fixed it.

**The Stranger:Me** · 21st December 2008, 17:44

Originally Posted by Motu

I changed the fluid in the BMW a couple of weeks ago - no problems at all.So how come Japanese bikes are such a pain to bleed hydraulics on? I've been bleeding brakes for decades,the only ones that give trouble are Japanese bikes....Japanese cars are fine.

Never had a problem loading a syringe and pushing the fluid in from the bleed nipple on the calliper.