Bleeding brakes

[nathanthepostman]

Need to bleed the front brakes after a botched brake pad change. I'm not overly mechanical but like to give these things a go. Does anyone know of any step by step guides out there, or is it just same as any other bike? (never done them on an ABS equipped bike, hence the hesitation)

Cheers

 

[Matty589]

What exactly happened? If the pads are dragging and the lever comes back to the bar/feels spongy it may not require a bleed.

 

[ghost-rider]

when you say botched brake pad change, wot exactly have you done????

 

[paddy]

brakes

i would take to a BMW retailer as ABS is a specialist job IMHO.

Paddy:aid

 

[nathanthepostman]

Schoolboy error really. Had the pads out to inspect. Pads need replacing. Left the pads out whilst I went to the shop and got some. Came back, moved the bike and instinctively brought it to a stop with the front lever.

Tried to squeeze the pistons back in but forgot to take the fluid reservoir off so the last one popped out. Cue gushing fluid all over the rental property's patio.

Reservoir cap off, pistons back in. New pads back in and a lever that comes all the way back to the bar.

I learn by trial and error and on this occasion there's been a lot of trial and a lot of error.

I'm keen to rectify it myself as then I'll know for next time. Though the bike is coming up a 6k service at which point they may swap the fluid anyway.

But again, I'd like to have a handle on how to rectify it myself. I've found guides to bleeding the old bike, with mention of refilling the fluid in the ABS reservoir beneath the seat. I'm thinking it must be the same on the LC but I'm not keen on going any further without a spot of guidance.

 

[auf_wiedersehen_pet]

I'll tackle pretty much anything (bike or car) but I never touch brakes. If it all goes wrong and I'm "in the dock" I want to point my finger at a professional mechanic. Brakes aren't worth taking chances with.

 

[Bake]

If you have lost that much fluid you will need some software i.e GS911 to open up the ABS ports otherwise you will never get the air out

 

[nathanthepostman]

Yes I'd read about the need for a gs911. It looks like this might be beyond me. I'd just be keen to learn the process should it be needed to be done mid trip anywhere, away from the dealership. Thanks for all the pointers. Appreciated

 

[JJH]

Bleeding brakes simply involves removing all the air from the system. Simply put you fill up the reservoir and keeping it full you pump the system trough using the lever or pedal to force the fluid trough the pipes and callipers. One of the trickey bits is that when you release the lever it tends to allow air to re enter the system by sucking it back in trough the nipple. There are various ways to get around this. You can open the nipple while pulling the lever and tighten to release lever just keep repeating till the air is bled. Then do the other front calliper. You can buy a nipple with a 1 way valve in it you can use a length of plastic tubing you can even use your finger. You can get a vacuum thing that connects to the bleed nipple and sucks the fresh fluid trough. You can get a bottle thing that keeps the resivour full automatically. The trick is never to ineavertly let air enter the system or you will have to start again. How do you know when it's properly bled? When you have a good solid brake lever push bike and operate lever and if bike stops it's a fair bet that you have susceeded. I don't know about needing a electronic device I have worked on a few abs brake systems cars and bikes and never had a problem. Good luck. JJH

 

[ghost-rider]

Bleeding brakes simply involves removing all the air from the system. Simply put you fill up the reservoir and keeping it full you pump the system trough using the lever or pedal to force the fluid trough the pipes and callipers. One of the trickey bits is that when you release the lever it tends to allow air to re enter the system by sucking it back in trough the nipple. There are various ways to get around this. You can open the nipple while pulling the lever and tighten to release lever just keep repeating till the air is bled. Then do the other front calliper. You can buy a nipple with a 1 way valve in it you can use a length of plastic tubing you can even use your finger. You can get a vacuum thing that connects to the bleed nipple and sucks the fresh fluid trough. You can get a bottle thing that keeps the resivour full automatically. The trick is never to ineavertly let air enter the system or you will have to start again. How do you know when it's properly bled? When you have a good solid brake lever push bike and operate lever and if bike stops it's a fair bet that you have susceeded. I don't know about needing a electronic device I have worked on a few abs brake systems cars and bikes and never had a problem. Good luck. JJH

yep, ill second this

 

[snaponphil]

I would give it a try as JJH suggests, I use a rubber/plastic tube over the bleed nipple into an old bottle with an inch or 2 of brake fluid in with the end of tube submerged, it does 2 things, 1, allows you to watch air coming out of the tube (bubbles) & 2, stops air being pulled back when you release brake lever.
Take it slowly & remember to keep reservoir topped up.

Good luck

 

[ninjarich1971]

If you want to bleed any brakes then do yourself a massive favour and get on eBay and buy yourself an easy bleeder. The best unit is the small one way valve which has a clear piece of pipe either end such as the sealey MS014. The valve is a small cylinder with an arrow on it for flow.
Simply push the pipe over the bleed nipple, crack it open and the gently pull the brake lever, leave the nipple open and once the liquid reaches the valve keep working the lever until no more air comes out then tighten the nipple and do other side. It really is that simple.
Do it all once and then leave the bike overnight with the front and rear brake levers pulled on, this should allow most air to rise back up into the reservoir. Refill then if the brake is still spongy redo the bleed until the brakes feel firm. If you have air in the servo then I believe you will get the abs fail light which may necessitate the gs911 but brake bleeding is quite simple if you use the correct tool.

 

[JJH]

I believe we are talking about a l/c? No servo on these models. JJH

 

[nathanthepostman]

Yeah it's a 2014 liquid cooled model. I do have one of those one way valve bleeding hoses for bleeding the brakes on a regular single caliper non-ABS bike. If it's as straight forward as that then I'm happy to give it a go. It took me a while last time but I got there.

It was just googling for any possible step through guides that I saw the reference to underseat ABS reservoirs on the TC and then this mention of needing GS911. I've clearly pumped some extra fluid from somewhere as when I squeezed the piston back in I had fluid overflow from the handlebar reservoir and the oil turned cloudy. I'm possibly wrong in assuming that there are separate reservoirs for the main brake line and for ABS and that when dealers do the brake fluid change at service time they simply switch that in the main brake fluid line and the oil in the ABS unit (if separate?) remains, hence the cloudy flush through.

As it currently stands I've got a full handlebar reservoir and no resistance in the brake lever. If from here it's just a case of bleeding the brakes through in a regular fashion then I'll give it a crack.

As I say, unfortunately trial and error at play.

 

[AndyR34]

As JJH et al have said, it's not too bad a job.
There are some videos on YouTube that show the ABS purge process that is done on servicings and fluid replacements ie. when using a GS911.
From what you've said, the problem appears to have been sorted but the first test ride will prove it :-0
Ride carefully...
Andy

 

[roamer]

If you have bled brakes before, and wish to do it have a go, dont re use the fluid,,
The abs will fault if you have air in, leave ignition off and bleed away,
the wheel circuits are separate so may be restored by thorough bleeding,
If you get a firm lever ,, start the bike no warnings all should be ok for a gentle test ride, only if its a firm lever, abs wont improve it,,
loads of people pop a piston out, as long as its clean and gone in without force its likeley to be ok,
roamer,

 

[ghost-rider]

a cheap way to "easy bleed" brakes from the caliper is using the spray mechanism from a household spray bottle bigger the better, give it a good clean first, the plastic tube attached to the spray mechanism end obviously wont go onto the bleed nipple, but this is easily rendered with a piece of small bore tube/pipe, fill the resovoir to the top and pump away, itll soon draw it through same way as an air operated easy bleeder would nipple at a time