hi i have had my fill this is my first BMW got it cheap so nogripes was a non runner prooved to be a duff fuel pump but now getting ready for MOT and hey presto no brakes at the front:evil:

tried bleeding but got no further i would apreciate any advice on what issues there are with the brake system on these bikes as i have only had kwaks for the past 20 odd years

decided i need a shaft drive and what better than german build so please please any even so small thing i should try would be apreciated as all the lights connected to ABS are having a hayday to themselves blinking there heads off

in advance thanks to all hwo give advice

Welcome wez1
first up, don't panic, it normally is the easy things that have cocked up.
You say no brakes, does that mean the brake lever pulls in without any pressure?, is there any release of fluid
down in the caliper or anywhere or maybe just the pistons are stuck in the caliper.
If you have worked on the Kwaka's brakes it shouldn't be too hard for you to pull it all apart. I'm a non mechanical person and still managed to renovate all my calipers and pistons etc with the help from these guys.
I found that I started with the brake lever, piston, master cylinder then brake lines and down to the caliper. Boy was I annoyed but in the end got it done.
I'm sure better people than me will chime in, but don't give up.
Cheers RT

Welcome wez. There's a wealth of info in the download section but first you need to slide on over to the new members section and stick up an intro. After a few posts crazy frog will give you a password to access then downloads. Also you can do a google forum search on the portal page to find posts on a particular topic.
88KE

wez1 wrote:hi i have had my fill this is my first BMW got it cheap so nogripes was a non runner prooved to be a duff fuel pump but now getting ready for MOT and hey presto no brakes at the front:evil:

tried bleeding but got no further i would apreciate any advice on what issues there are with the brake system on these bikes as i have only had kwaks for the past 20 odd years

decided i need a shaft drive and what better than german build so please please any even so small thing i should try would be apreciated as all the lights connected to ABS are having a hayday to themselves blinking there heads off

in advance thanks to all hwo give advice

Welcome to the forum. When you get a mo' please go to the 'Member's Introduction' page and tell us a bit about your bike, oh, and yourself too. And fill us in when you ask a question as to what exactly your bike is. It helps us to make an easier diagnosis if we have that basic bit of info, as it appears nowhere in your question post. Cheers.

The brakes will work if the lights are blinking it can mean many things but it sounds like you need to fix the actual brakes first and then reset the ABS computer.
I pull the whole lot apart when I get a bike and clean the calipers and pistons and put new seals and O rings in and new pads as well.
Bleed the brakes starting with the ABS modulator and then to the calipers.
The front calipers can be quite difficult to bleed because of the crossover tube from right to left caliper. I have used a vacuum bleeder that I made but they are available from fleabay for around $40.
Once the brakes actually work again you can set about reseting the ABS computer.
Yeah also Wez put up what model of bike you have as it can help when giving help.
Depending on which model you have depends on how ABS is wired.

Welcome to the forum Wez - you will find all the information that you need here. If you can't find what you need then just ask

RT wrote:Welcome wez1
first up, don't panic, it normally is the easy things that have cocked up.
You say no brakes, does that mean the brake lever pulls in without any pressure?, is there any release of fluid
down in the caliper or anywhere or maybe just the pistons are stuck in the caliper.
If you have worked on the Kwaka's brakes it shouldn't be too hard for you to pull it all apart. I'm a non mechanical person and still managed to renovate all my calipers and pistons etc with the help from these guys.
I found that I started with the brake lever, piston, master cylinder then brake lines and down to the caliper. Boy was I annoyed but in the end got it done.
I'm sure better people than me will chime in, but don't give up.
Cheers RT

hi i'm a panel beater and have years of experience in mechanics but this has dumfounded me i have checked everything i can think except the electrics.

problem is that when i clamp the pipe to the callipers i have good pressure but on release the pressure dwindles to near zero. just been reading another answer and think the tube bridging between callipers could be the problem will try again never thought of that lol.

wes ...you havent overfilled the master cylinder ?

if so the piston seal will just pull the fluid back up the lines as there is no valve action possible because of the vacume created by the bladder and lack of airspace .

other wise its pretty common that the master piston breather valve (valve situated pretty near a centimeter closer to the presure point of the master piston , different to the fluid feed to the piston assembly propper ) could be blocked with gunk not allowing the pump type action to happen ..
a clean out ...or probe of this hole can be acheived pretty easy from the filler top ...if you evacuate some of the fluid to see what you are doing ...and maybe a pipe cleaner as a probe ...
of corse change all the fluids once completed to keep the whole deal clean and happy .

yeah done the usual and made sure it was all clean. am going to ahav another bash at it to day, trouble is that there is fluid coming out when bleeding and no sign of anu air in the syatem. i have pressure when i clamp the front brake pipe and when i release it then try pumping i get zero pressure on the line and that is xausing me my headache. after readin the comments all have posted so far( thanks by the way to all) i am going to try to evacuate the connecting pipe and will then post result. lol

thanks

When you say clamp the front line I presume you mean that you put some vise grips on the rubber line and then try to pump and the master cylinder comes up with a hard lever.
There are 2 rubber lines the first at the master cylinder to the solid line going to the left side modulator and the other where the line from that modulator goes to the right side caliper.
Which one did you clamp because it either means the air is in the modulator and the calipers or just the calipers.
Bleeding the modulators is fairly easy and usually straight forward but as said before the calipers can be very difficult if not impossible.
The K100 I had till recently it was impossible and I made a vacuum bleeder and spent hours getting all the air out.
One thing I have done to other bikes that prooved difficult was to let the system settle overnight with the lever tied tightly to the handlebar, this apparently lets any air in the lines to rise back to the master cylinder.

Another trick is to use a lever to spread the pads so pushing the pistons back into the caliper forcing any air out then pump the calipers back onto the discs.

You can hold or tie the lever in and spread the pads on the right disc while bleeding the left caliper this forces the air to the left caliper then hopefully out of the system

One trick I used recently was to put a thick piece or rubber matting between the pad and disc (you need to use well worn pads to do this) and pump the lever till you get some sort of lever then bleed till fluid stops. This lets more fluid out each time so getting more air out.

One more thing is that the fitting at the master cylinder can sometimes hold air and needs bleeding by just holding the lever in and cracking the bolt. Often a lot of air will come out.

yeah RICK i think you got it right i just read your post after being at the brakes all day i tried all of the things you have mentioned and made on progress i finished up trying a few things one i did clamp the front pipe not the one leading to modulator. i get full pressure then.so i continued by taking each calliper and trying them on there own and they both work perfect and have normal pressure when attached to the master cylinder on their own but when i put them back on the bike the pressure is zero after riggoruos bleeding and rebleading i have near to nopressure so i am at a loss as to the fault the pressure is there when i clamp the front brake line and when irelease it and try it again the pressure is zero ihave no idea what ican be there is no air in the lines of that ia pretty sure . is it possible that yhe callipers are duff? cheers

will keep updating till i find it LOL but any more advice is very welcom if nothing else i can use bike as ballast on back of landy when offroading next week lol

Let's step back when you clamp the line leading from the master cylinder there is pressure and a hard lever, when you connect the lever direct to the callipers there is a hard lever and pressure? So that says to me the bit in the middle has air in it. When you bled the ABS modulator at the modulator did you get air out? Just had a silly thought when you bled the modulator you didn't by chance bleed the modulator for the rear brakes? Could you describe in detail how you are bleeding the system please just so we can be sure we are all thinking the same process.
Regards,
K-BIKE

From what you say the line joining the calipers is the problem, just like I had.
Try removing the calipers and inverting them for a while to get the air out of the line, you may need to do it a few times.
One thing I did many years ago on a very stuborne car (MK2 Zephyr) was to connect a long tube from the futherest wheel to the top of the master cylinder and sat in the car ,read a book and pumped the pedal for an hour or more till all the air came out then moved to the next wheel.
I did end up with brakes but the guy next door did ask why I was sitting in the car reading when the house was more comfortable. He was very unmechanical and definately didn't understand the explanation at all and for evermore thought I was just strange, maybe he was right.

Dont worry about using new fluid till you get it right and then replace it with new.

hi K Bike thanks but i did bleed the right modulator:) but the problem persists the idea of RICK is my thought to but i tried using seperate lines using a spliter and fitting bleed nipples to each calliper and bleeding seperatly and still get the same darned result i find it kind of wierd is there any other brake setup that will fit in there place with the abs still usable that is my idea next i need the bike to comute to uni (old student lol) so i have a few weeks to tinker around but would much prefer riding than fixing...

Check the rubber lines. This is starting to sound like a problem I struck a while ago with the rear brake. The rubber line had cracked at the fitting on the Modulator but didn't leak out but into the next layer of the hose causing a big bubble in the line and very poor brakes. Put the fingers round each line on the rubber right next to the fitting and pump the lever you may feel the line expanding as you pump.
It drove me nuts for hours and plenty of head scratching till I saw this bubble the size of a marble and BTW it can happen anywhere along the line but at the fittings is more common.

rubber lines are fine checked them over more than once but when finance is better o will be upgrading to braided lines for sure. got to find the problem first gave up today had to paint a couple of bike wheels and replace a doorskin on my uncle's mgb gt lol.need the cash for bits and bobs on the K but tomorrow i'm going to try some more stuff on the bike i am about mad trying

rubber lines are fine checked them over more than once but when finance is better o will be upgrading to braided lines for sure. got to find the problem first gave up today had to paint a couple of bike wheels and replace a doorskin on my uncle's mgb gt lol.need the cash for bits and bobs on the K but tomorrow i'm going to try some more stuff on the bike i am about mad trying

I know you checked the master cylinder but are all the small holes in the master cylinder free of blockage? One option is to suck the fluid up from the bottom cylinders (put a liberal coat of silicone grease around the bleed nipples so as to stop air being sucked in at that point) then using a modified master cylinder cover and suck with a Mityvac at the master cylinder so any air is encouraged to rise.

Before trying anything else have you followed the bleed process in the BMW manual to the letter? I ask this because different people have different ways of bleeding brakes.

Before you modify the standard setup almost everyone on the list has the standard setup and it works so there has to be a reason (other than demonic possession) why it is being so difficult to bleed.
Regards,
K-BIKE

thanks K-Bike i am going to try again to bleed them but first i need to get hold af a new callipeer as i broke the bleeding nipple on the lefthand one

i will then try the way the manual says it should b done once i get hold of one. but initially i think the problem is the bridging line as i get good pressure when i connect the callipers directly to the brake line one by one so will keep my progress posted as it goes

The K1100 has a T piece and seperate lines going to each caliper and was heaps easier to bleed and on the K100 when I got rid of the ABS I had the same setup and it was great, no problems at all.

hi Rick been thinking about putting a T piece in an using two bleed nipple's wonder if it would effect the abs function though. it should'nt though but i'm not sure. it would make bleeding an easy thing though. cheers

The early K11s have the same ABS with a T piece I dont see how it could affect it.
The two bleeders certainly make it easy.
My K75 has the crossover tube and it is a real PITA as was the K100.

i tried that today and been at it for hojurs trying different things lol

discovered something interesting that iam going to try called braided brake lines HA HA i have come to the comnclusion that although one brake has enough pressure wehn connected and the other side has enough pressure when connected but upon connecting both together and bleeding for hours and hours the pressure is still zero, i have to admit defeat. i am going to try graided hoses and then will get back with the results

going to sit down with a wee dram now and consider the fruitless day of fails

yo hey got good news lol thanks t all the helpfull comments and the advice given i have re worked all the piping on the front brakes fitted a tpiece and braided hoses after plenty bleeding and a little cursing i now have front brakes

but the hair in the soup is that i found that it was due to the anti squeel shim in the brakes that the brakes wer retracting to far and therfor the pressure or distance i had to pul the brake lever was < than could be compensated lol

now i have to tacle the ABS non function but can at last MOT the bike

once again thanks for the advice all of you were willing to part with and i apreceate it lots

i owe you a beer or two if we get the cahnce to meet

Good news Wez if you get a password from Crazy Frog aka Bert you will get access to the downloads page and find how to reset the ABS computer which is probably all that is needed.

cheers will do when i get round to it bit of cash flow problem lol

I think CF also accept credit cards.

yeah cool if you have one lol