After my latest discovery's, I thought it was time to write something about the brakes on our (or any) bikes.
The bikes we own are mostly more than 10 years old an although they can still be lowmilage or revised before, usually nobody really cares about the brakes.
Sure when I get another bike I check pads, change fluid, maybe use a screwdriver to clean the pistons......
Oh and almost forget, the rest of the time we complain about that the pads 'stick' after your bike is standing somewhere for a few days.
|This is due to water that has got under the dustseal (at first) it doesn't get away from there and so it sits and reacts with the metal around it.
Pushing out and deforming the rubber seals, because there is no space to push them out.
First I'm going to tell you what it costs if you do this yourself, then we'll talk about if you are going to do it or not.
- 15 Euro for a set of new Orings and cupper rivets (2 per connection) for one brake (you've got like 3, probably)
- 5 Euro for 1/2 liter of brake fluid (I don't know my conversiontool doesn't cover this yet ;)
- A lot of time too bleed everything that has been disconnected (unaffordable)
- 20 cents of toiletpaper (the cheapest is the best)
- Water, the more you spill, the more you need.
- some new skin transplant where the brakefluid has been. (you could use gloves, but it doesn't work that well)
- some new paint if you thought the plenty water idea was not for you, or if you have spilt it already.
- transparent tubing, buy it in a bike shop 2 Euro/meter (i can do that, 1.7 $ for 3 foot)
- a jar, or empty brake fluid bottle or whatever
Instead of the last 7 items you could let somebody else do it for you or get some handy tool for bleeding yourself, they are about 150 Euro.
And if you have enough of this attitude, you can immediately go here to see what you should do
So it's pretty cheap, but can be time consuming if you loosen more than one joint
And why should you?
To remove the antidive out of the system or use different brake lines.
And why you should do it when it still works is easy too.
If you look around on this website you can find some indications that I crashed my turbo.
The reason for this was because my front brake seized (that is: too loose grip again)
As a -almost- direct result of this I made a summersault after leaving the bike with haste, and so did my bike.
When everything was back to normal the cost were:
- one engine about 1200 Euro
- one bent frame 350 Euro
- one damaged left side, 9 month of recovering, first 3 month in wheelchair
- one new exhaust (shit, 350 Euro)
- a new set of clothing and helmet
- some new skin one one part of my leg and some of my foot where i lost my hiking boots (german quality, meindl) during the accident
- a new pair of hiking boots 200 Euro, to have a 'proteced' foot and being able to walk more or less(same brand, very good quality, no i don't sell em)
- all cosmetics for my bike, can't even make a guess but let's say 600 Euro.
This was due to neglecting to really get the pistons out of the brakes, visual inspection showed it was ok and it was just a bit sticky.
But when i got the pistons out i found that the corrosion had jammed the piston in it's housing when it heated up due to the fact that i used the brake.
So if you take a look at the figures it's a lot cheaper and faster to dismantle your brakes every year, especially if you live in a country with a high humidity.
We had that discussion on the website just the other day and I'm agains using 5.1 brake fluid because it doesn't mix the water, but leaves it on the bottom of your brakes, this is no problem if you have revised the whole system, but if you have an old system it will be more porous and thus attract more water.
And the water built up in your brakes happens faster thus if you use the 5.1 fluid.
Water built up in your brakes is also a funny experience.
You've been riding for some time, minding your own, everything is sweet and suddenly some F$@$#@%# moron pulls up from his driveway and because of all other traffic the only thing you can do is BRAKE Almost hit the tarmac but excellent heavy stop Pfew, made it, cagers.....
Anyway back on the road a left here, you're thinking 'just have to touch the brake to make the corner', and then almost no brake, squeezing deeper....too much speed for this corner, pumping the brake, no chance of getting back in a straight line again..some bushes come up...pumping the brake....half way down the bushes you stand still and think about what has happened, check the brakes, no leaks, and by the time your heartbeat is back to normal you're brakes have cooled down enough to have some brakes again.
Technically, the water built up happens on the lowest point of your brake lines, because water is heavier than brake fluid.
In practise that is close to your brake piston.
While braking your brakes heat up, but with that emergency stop, the pressure built up in combination with the brake temp rising was enough to turn the water into steam, making the pressure rise and let more water turn into steam (and let you brake even harder)
Now you ride again and your brakes are again a bit cooled down, the steam turn into water, leaving 'air-bubbles' in your brake line, figure out what happens if you hit them again half a minute later.
But this is more why you should bleed your brakes.
It's time to get back to buisness
You decided to do your brakes, because you are never going to apply in a circus nor like summersaults.
First decide if you only want to do the brakes themselves (every year is not a bad idea because of the low costs)
Get all parts in before you start!
loosen all imbuss bolts used to mount the dividing block, antidive units and bolts that hold the brakes
lift the brakes as high as the reservoir, or higher if possible, so they don't leak empty when you are working on the brakes put a bin under it and loosen the bolt that holds the brake line.
If you really want to bleed everything and want to bitch about it for several days, it's naturally preferable to let go of all brake fluid via a transparent tube and the bleeders than this (that's were the toiletpaper comes in handy, you can dip it in water and sqeeze it between the nudgard and connection joint or aound the other nipples, it prevents laque damage.
But this is just if you want to do it in one day and have a good result.
After loosing the bleeder you can pour the fluid out, a bolt can close down the other hole, and with use of a bike-pump (and som real fast pumping, carefull you're finger is not between the piston and the clamp when it pops out but some toiletpaper or a rag)
Other solutions are an air gun, or pressing them out with the brakefluid when stiil connected, but this gives a VERY messy result, and you again have to bleed the whole system out.
When am I gettting there huh?
Get the rubber rings out and put the piston in a jar of degreaser ( i always use,...look that up later, some industrial reusable stuff)
Just let it soak in there for an hour, it better than scrubsponges, or metal parts against the pistons.
check where the Orings sit if there is corrosion, this will deform your O ring, press it out a narrows down the free space of the piston, making it seize.
Clean out the corrosion, be carefull not to make deep scratches, put some vaseline on the rubber rings before putting them back.
Inspect the clean, degreased piston, the little scrathes you see on this enlargement are from using screwdrivers and other hard objects to 'clean' the pistons, without taking your brakes apart.
It makes your brakes more sensitive to water and chances to start leaking bigger.
The black spots you see are holes in the chromewall and thus making the piston not suitable for reuse, unless you want to take that risk.
If you see the crud in your brakes, you know why you should have done this before