Bleeding ABS brakes on an 1150 - how do I do it?

[balbas]

Bleeding in both sense of the word...

I hadn't been using the 1150 as I had an 18 month dalliance with a 1200GSA, so the old girl was stuck at the back of the garage.

Now the 1200 is gone, the 1150 has been dragged back out and I made the mistake of cleaning the calipers out pre-MOT. I've now got air in the system and despite 3 or so litres of brake fluid being bled through I still get a spongy lever. Firms up after one pump which is great - indicates to me that the master cylinder isn't fubar'd and that it's air in the lines somewhere - but obviously it's not safe to ride.

So - the tank has been off and I've cracked the bleed nipples on the ABS unit as well as the calipers - I've bled through until there are no bubbles and I still have air in the lines.

Admittedly the one thing I've not done is initialise the ABS unit whilst bleeding by turning on the ignition - is that worth doing?

I have never, ever experienced a brake system so frustrating to bleed (although my old SIIa Landrover runs it close).

What's the technique? What's the bleed sequence I should be working in? I have looked at the online guides and done a search here, and unfortunately what is advised won't work on my ABS unit as I don't have 'resevoir fill caps' on the ABS unit. Crappy picture attached (apologies for the quality - poor light and iphone camera are not a good combination) of my ABS unit.

If anyone can shed any light on it, I would be really really grateful as I'm tearing my hair out and bankrupting myself in buying more Dot 4 than one person should ever need. 'S an early 1150 - on a V plate with the old ABS that clunks alarmingly as you set off - think it's called the system ABS but could be wrong.

Cack the system won't let me post attachments - that'll have to wait until I subscribe then. In the meantime any advice still very gratefully rec'd

 

[DrFarkoff]

If you turn on the ignition Do you have 2 red ABS rectangles that flash together? (As you say you have no filler caps on the ABS unit)

If so You're on a winner its ABSII the best type!

Try Leaving the bike on the sidestand with the Brake frimed up and cable tied back to the handlebar overnight and then just to be sure bleed the Nipples on the ABS unit V = Vorderread or front wheel and H = hinterrad or rear wheel they are cast on the body by the nipples

 

[balbas]

Yup it's the type with the two great big Tandy style red flashing rectangles.

Don't understand exactly what you're saying - the brake frimed up?

I get the bit about leaving it on the sidestand with the lever cable tied back, but do I then just bleed the ABS nipple, or do I also do the calipers too?

Many thanks for the response so far though.

 

[DrFarkoff]

Pump the brake up so it is FIRM

Then cable tied it back so that it remains under pressure

Air bubbles tend to float to highest point under these conditions

I also found in the past that brake pipe connector that is at the headstock has an airlock point so you can carefully slacken the connector and gently pressurise the system and see if you are getting air bubbles if not lock it up and seek elsewhere

 

[balbas]

Cool, will firm up the brakes and stick it on the sidestand tonight with the lever cable tied back.

Fingers crossed it'll work this time. Does that mean then that I'll not have to bleed the calipers again? Just the ABS unit?

 

[ELIMINATOR]

My understanding is that the Servo needs to be running to blled the brakes properly.

http://www.ukgser.com/forums/showthread.php?t=229221&highlight=servo+bleeding

http://www.ukgser.com/forums/showthread.php?t=161516&highlight=servo+bleeding

 

[DrFarkoff]

2 big rectangular lamps with ABS written in both that flash on off together when the ignition is switched on and it makes a clank clank sound as you ride off? is ABS II on an oilhead

If you switch on and you have a quick blinking triangle in a square lamp and loads of whirring an pooh from under tank it's servo ABS and it's schite when it goes wrong!

I had an 1150RT lock the front wheel at 20mph and then the diagnostics for the unit claimed that the front pressure was low Not in My book Too Dodgey too complicated and I'm sure a lot of folks have got hurt with it!

My understanding is that the Servo needs to be running to blled the brakes properly.

http://www.ukgser.com/forums/showthread.php?t=229221&highlight=servo+bleeding

http://www.ukgser.com/forums/showthread.php?t=161516&highlight=servo+bleeding

 

[balbas]

2 big rectangular lamps with ABS written in both that flash on off together when the ignition is switched on and it makes a clank clank sound as you ride off? is ABS II on an oilhead

That's the badger. As far as I am aware, having the ABS unit initialised should make no difference, but if all else fails, I will try bleeding with the ABS unit turned on.

 

[Steptoe]

, I will try bleeding with the ABS unit turned on.

Don't bother, it will do nothing. You're confusing servo brakes with your Abs. You have the vanilla ABS.

If you broken into the system you should bleed it through the ABS modulator first, and then at the calipers. But seeing as you've pissed about changing caliper seals nothing posted so far will help you.

You need to back fill it from the calipers.

 

[balbas]

Don't bother, it will do nothing. You're confusing servo brakes with your Abs. You have the vanilla ABS.

If you broken into the system you should bleed it through the ABS modulator first, and then at the calipers. But seeing as you've pissed about changing caliper seals nothing posted so far will help you.

You need to back fill it from the calipers.

I wouldn't say there was any confusion, it was more a case of desperation... And it wasn't pissing about, it was unsiezing the calipers, which was essential. Anyway... Right, back filling from the calipers, I'll be needing a mityvac then will I? And if so, how to bleed? Back fill from one of the calipers and only bleed from the ABS unit? Or not bleed at all and try to push the air through the master cylinder?

On a slight tangent, I've been warned elsewhere that pushing fluid back through the master cylinder can cause the seals to fail, seems like codswallop to me but is that something that I should be thinking about?

Many thanks.

 

[MattW]

I wouldn't say there was any confusion, it was more a case of desperation... And it wasn't pissing about, it was unsiezing the calipers, which was essential. Anyway... Right, back filling from the calipers, I'll be needing a mityvac then will I? And if so, how to bleed? Back fill from one of the calipers and only bleed from the ABS unit? Or not bleed at all and try to push the air through the master cylinder?

On a slight tangent, I've been warned elsewhere that pushing fluid back through the master cylinder can cause the seals to fail, seems like codswallop to me but is that something that I should be thinking about?

Many thanks.

Large syringe (ebay or your local vet) and some plastic tube for backfilling (and another one for removing excess fluid from the MC reservoir). If you're unlucky you can invert the seals in a mastercylinder by forcing the pistons back in the calliper during a pad change - however as you'll have a bleed nipple open in this case it won't happen (not enough pressure). I've only ever seen this written about certain cars (my Honda for example) - never a BMW bike - not saying you're wrong though...

As to the sequence - no idea - that's a Steptoe question

 

[Steptoe]

I have looked at the online guides and done a search here, and unfortunately what is advised won't work on my ABS unit as I don't have 'resevoir fill caps' on the ABS unit.

- think it's called the system ABS but could be wrong.

I wouldn't say there was any confusion, .

Sounds like confusion, smells like confusion, looks like confusion.

Unless i'm confused

 

[fayeslane]

To bleed the brakes on my K1 (ABS1) I ended up buying a vacuum bleeder unit, that works of an air compressor, after trying every other trick. Best $80 Oz dollars I have spent but still took a litre of fluid through the system to get to where I was happy with it. Owning a few bikes I reckon it'll pay for itself quickly.

 

[balbas]

Sounds like confusion, smells like confusion, looks like confusion.

Unless i'm confused

If it smells like confusion it probably is. Otherwise I wouldn't be here asking for advice I suppose...

Ok then, big syringe - check, I'll be down to the farm supplies place after work to get a cow syringe. Now, what order do I inject the fluid in? And I assume its only to be 'bled' from the master cylinder resevoir? I think I'm sure what I'm doing here, but don't particularly want to waste more time..

Cheers.

 

[Stewart H]

If it smells like confusion it probably is. Otherwise I wouldn't be here asking for advice I suppose...

Ok then, big syringe - check, I'll be down to the farm supplies place after work to get a cow syringe. Now, what order do I inject the fluid in? And I assume its only to be 'bled' from the master cylinder resevoir? I think I'm sure what I'm doing here, but don't particularly want to waste more time..

Cheers.

I use a couple of those syringes and some plastic tube that is a snug fit on the bleed nipple, cut a few inches of the tube, fit it to the bigger of your syringes, playing doctors fill your syringe and tube with clean brake fluid taking care not to get air in there, pop a spanner onto the bleed nipple, loosen it then fit your syringe and pipe deftly on there without getting any bubbles in, you should have removed the reservoir top already and using the other syringe almost emptied the old fluid out, pushing the plunger on the lower syringe should see the reservoir filling, repeat as necessary, it is also possible to bleed the under tank ABS units in a similar way, using another chunk of the plastic pipe to take away the old fluid and still filling from the bottom, must pop out to the garage and see what size syringe I use, 60ml I think, I also finish off by tying the lever back overnight.
Stewart

 

[MattW]

I did just what Stewart says but I couldn't fit the tube to the nipple without introducing some air, so I used this sequence:

1. Fill syringe and tube with new fluid, leaving a bit of room in the syringe.
2. Fit full syringe and tube to closed bleed nipple.
3. Holding the syringe pointing down, open nipple and draw a little fluid from the calliper into the syringe.
4. This pulls any air trapped in the nipple into the syringe - wait for any bubbles to rise to the top of the syringe underneath the plunger.
5. Once the bubbles have all risen, flush through as Stewart says making sure you keep the syringe pointing down so you don't reintroduce the air bubble you've withdrawn.

I have a couple of big 'horse sized' 100ml syringes.

 

[Stewart H]

Just checked my syringes, 60ml, but your 100ml jobs would be better Matt

Stewart

 

[balbas]

Is there any particular order the brakes should be pressure bled in? And roughly how much fluid needs to go through each line?

So far, starting at the LH caliper, then moving to the RH caliper and then the ABS module, I've bled through 120ml of fluid at each nipple and still have a spongy lever

 

[Stewart H]

Is there any particular order the brakes should be pressure bled in? And roughly how much fluid needs to go through each line?

So far, starting at the LH caliper, then moving to the RH caliper and then the ABS module, I've bled through 120ml of fluid at each nipple and still have a spongy lever

I cant speak for others but I buy fluid by the litre from my local factors and tend not to worry about how much goes through, it cleans all the old stuff out and any crap can go with it, dont be mean, push it through, just make sure the reservoir doesnt overflow.

Stewart

 

[balbas]

I cant speak for others but I buy fluid by the litre from my local factors and tend not to worry about how much goes through, it cleans all the old stuff out and any crap can go with it, dont be mean, push it through, just make sure the reservoir doesnt overflow.

Stewart

Yup, except that I'm pretty sure I've re-filled the lines from the top and now also from the bottom and I still have air in there.

I've bled loads of brakes and never had problems like this. I just don't get what I'm doing wrong.