Brakes or rather -no brakes

[I of the Strom]

I found that it made a difference backing off the banjos slightly on top of the ABS unit whilst pressurising the system via the levers. As they sit at an angle, air can get trapped in the annular space of the banjo where it can't get out without being slacked off and pushed out by the fluid from the lever pressure.

Thanks for that. What symptoms does this problem display, ie. does my issue sound familiar, or am I in a whole big heap of ....... ?

 

[Steptoe]

When you replaced the master cylinder piston did put the new one back in the right way around ? - it is easy to put it in back to front which gives the symptoms you now have.

 

[I of the Strom]

When you replaced the master cylinder piston did put the new one back in the right way around ? - it is easy to put it in back to front which gives the symptoms you now have.

Oh I hope your right but I believe I put it in the right way round. It came with some white grease in the end for the push rod to locate into (I assumed) and therefore put it in that way round. However, I now can't remember which way the 'blades' of the seals were facing so will probably start by taking the master cylinder apart before ripping the callipers apart. Am also going to try the easing off of the banjos at the ABS but I think the problem may be bigger than that. I have various makes of bikes stretching from '76' to '06' plates and have never experienced this level of problem with brake bleeding - honest I'm not completely handless but appear to be making a right a**e of this !

 

[I of the Strom]

Contingency PLan and compatibility

Looking on Flea Bay and there are some callipers and master cylinder off a 2002 1150 GS for sale. Will these be compatible with the 1100 GS set up.

So far only items not changed are the callipers, master cylinder and the ABS unit.

Desperation and lack of funds make for desperate measures.

 

[I of the Strom]

Ok It could be any one of a number of things causing my problem. I have acted on all advice given but to no avail. So, I own a couple of modern CCM's that have nice Brembo master cylinders at one end and Brembo callipers at the other end of a nice long length of quality braided brake hose. These brake are working perfectly so components from here are safe to use in the 'elimination' of variables in the beemers front brake system.

Take one nice long piece of hose and attach it to the Beemers master cylinder and then to first one and then the other front calliper, bleeding the system and checking for brakes as you go. Bingo, both master cylinder and the callipers worked just fine and I was able to produce excellent lever movement and firm brake pressure in both callipers. The problem has to lie elsewhere. Good, I have eliminated potential sources of the problem - bad as I still don't know where the problem lies but have an idea now where to look. Either air is sitting in the brake lines and all those connections or the ABS unit under the tank is FUBB'd and is doing likewise to my front brakes. I ask, is the noise that my ABS unit makes when I release the pressure on the lever normal - I can here it sucking/blowing even with the tank in situ ?
Tomorrow after checking that there has been no deterioration in the pressure overnight I am going to tidy all ends up and then take the bike for a test drive and see if the simplified single line system works under road use pressure - first one then the other. This way I'll know that at least I have the means of creating a working brake system minus all the connections and the ABS unit. Anybody else running single lines for front brakes, if so, what length did you have made up ?

 

[I of the Strom]

Note of Warning

Been out for the test ride and all works as it should however, a Note of Warning to anyone that considers doing similar. I closed off the calliper that wasn't connected to the master cylinder with two nipples. The residue fluid and air mixture built up sufficient heat related pressure to activate the calliper sufficient enough for me to nearly loose the front end pulling away at some traffic lights. Opened valves released pressure, no problems. The brakes worked well with a single calliper easily pulling the bike up to a safe and controlled stop from 60mph. I would therefore expect that with both working with direct lines the brake capabilities would be more than adequate.
I am now going to start the bleeding process for the 'natural' brake system all over again but this time starting with new pads in place and callipers minus blocks of wood fitted in situ and ready to work against the discs. I will ease off banjos and connectors as I go and hopefully make progress. 'magin' having to do this in the back of beyond - this hassle plus a front mudguard that gets in the way of wheel removal, fuel lines that need clipped back etc etc - hardly the go anywhere bike as made out !!! As a back up, does GS SHOP carry the parts for bypassing the ABS unit and providing a direct link between master cylinder and callipers ?

 

[Stewart H]

Sounds drastic when all you need to do is get the bleeding right.

 

[I of the Strom]

Sounds drastic when all you need to do is get the bleeding right.

Ach well proved that the components are ok. Think its going to be off to the dealers in Bishopbriggs as don't know what else to do as have bled and bled these brakes but have never seen anything like this nor had this much trouble.

 

[I of the Strom]

Sorted

Good brakes both back and front but no active ABS - can live without that as I'm off on my hols !!!! Thanks to all for their input and especially Michael at Bishopbriggs Motorrad for his patience and guidance. Still don't know why the brakes just ceased to work/exist nor why after the first rebuild and bleedings they would disappear completely on the test ride, but, they're good and strong now. The bike goes and stops as and when required and that'll do for now. Off up the west coast so I'll find out how to load up pics when I get back. Oh, hope you all enjoyed the royal wedding - me ? I was riding my bike...