HELP - Low Brake Fluid

[Deleted account 210609001]

A few times over the past week or two, I've had my warning lights on shortly after starting off for the morning - red triangle and 'brake failure' flashing alternately. Handbook suggests this means brake fluid is low.

Turning the ignition off and starting again has resolved the problem.

I've checked brake fluid levels in front and rear master cylinder, and they're both at the maximum marker. There is no sign of any leakage anywhere in the brake lines.

Am I missing something stupid, like checking and/or topping up the ABS system somewhere?

Thanks,

Robin.

 

[Slowdown]

The HOWTO on your brake fluid change is here:

http://advwisdom.hogranch.com/Wisdom/service_abs3.pdf

You've more than one resevoir, I think.....


and ask in GSpot on ADVRider.com - the yanks are still awake and there's thousands of them!

 

[Fanum]

How old is your battery Robin, and is it in good nick/charged fully?

 

[Deleted account 210609001]

The HOWTO on your brake fluid change is here:

http://advwisdom.hogranch.com/Wisdom/service_abs3.pdf

You've more than one resevoir, I think.....


and ask in GSpot on ADVRider.com - the yanks are still awake and there's thousands of them!

Thanks, will check that.

How old is your battery Robin, and is it in good nick/charged fully?

Yes, new-ish Odyssey, on a trickle charger, no starting problems.

 

[Fanum]

Thanks, will check that.



Yes, new-ish Odyssey, on a trickle charger, no starting problems.

Change the rear bulb as a first step...even if both filaments look ok.....for the 50p it'll cost you, it's worth eliminating.
check both microswitches are operating (you should hear the little clicks on lever operation.

Beyond that
sorry...12's are not my thing

 

[Steptoe]

Check the fluid levels in the servo unit under the tank.

 

[Pukmeister]

Or alternatively, check how worn your brake pads are.

As the pads wear, the ABS units internal reservoir level will fall as the brake pistons move further out from the calipers. They may be very close to needing replacement.

The handlebar/footbrake reservoirs are pilot operating circuits so the their levels wont appear to drop as pads wear.

By fitting new brake pads, the pistons have to be pushed back into their bores in the caliper, thus raising the brake fluid level back to its original state.

Simple really.

As an aside, the ABS computer logs a low fluid reservoir level warning well before the warning triangle gets displayed, if you had access to a GS911 unit it would tell you this as part of the fault code readings.

 

[leinsterrugby]

Or you could just be unlucky like me and have to replace the entire ABS/servo unit

 

[Deleted account 210609001]

Check the fluid levels in the servo unit under the tank.

Thanks.

Or alternatively, check how worn your brake pads are.

As the pads wear, the ABS units internal reservoir level will fall as the brake pistons move further out from the calipers. They may be very close to needing replacement.

The handlebar/footbrake reservoirs are pilot operating circuits so the their levels wont appear to drop as pads wear.

By fitting new brake pads, the pistons have to be pushed back into their bores in the caliper, thus raising the brake fluid level back to its original state.

Simple really.

As an aside, the ABS computer logs a low fluid reservoir level warning well before the warning triangle gets displayed, if you had access to a GS911 unit it would tell you this as part of the fault code readings.

Thanks, that makes perfect sense. Brake pads look ok though. I'll take it to be plugged into a machine next time i'm passing one.

Or you could just be unlucky like me and have to replace the entire ABS/servo unit

You're a ray of sunshine, aren't you? God knows what mood you'll be in after tomorrow's match.

 

[JFC]

it happended to me - combination of worn disc and pads meant internal resevoir level dropped and red triangle etc,

 

[Deleted account 210609001]

Thanks, chaps. I've topped up the ABS reservoir, which was surprisingly simple. No idea how much it needed so I used the scientific method of putting "a bit" in each circuit (front and rear). Seems to have worked.

Discs are not overly worn (a pity, as I fancy some of those cast iron ones Motorworks flog) and pads not overly worn either. Maybe it wasn't quite topped up enough last time it was changed so minimal wear caused the symptoms.

Of course, there might be a leak, but I'll have it checked out in a couple of weeks time so it should be ok until then.

 

[Deleted account 210609001]

ABS Warning Lights

A different combination if warning lights today - red triangle constant, "brake failure" flashing fast. Happened two or three times on a quick ride today, went away by turning ignition off then starting again, but cam back again. Also, the speedo stopped working.

This led ot me to believe the ABS/speed sensor at teh back might be on the way out. Pulled it out, gave it a wipe, put it back, went for another spin and it seemed to be ok. Who knows...

 

[John Armstrong]

This led ot me to believe the ABS/speed sensor at teh back might be on the way out. Pulled it out, gave it a wipe, put it back, went for another spin and it seemed to be ok. Who knows...

As a lot of those type of sensors use a magnetic principle, any ferrous swarf wafting about can be attracted to the sensor and give strange readings.

 

[Brian ROSEN]

No more

A different combination if warning lights today - red triangle constant, "brake failure" flashing fast. Happened two or three times on a quick ride today, went away by turning ignition off then starting again, but cam back again. Also, the speedo stopped working.
This led ot me to believe the ABS/speed sensor at teh back might be on the way out. Pulled it out, gave it a wipe, put it back, went for another spin and it seemed to be ok. Who knows...

Please stop solving your own problems Robin. you will put this forum out of business;

 

[Deleted account 210609001]

Well, I've been out for a more extensive ride today, and not had a repeat of yesterday's problems. I've tried every combination of hard and gentle front and rear braking, including repeating the route and junctions I used yesterday, but can't replicate the problem. Might just be coindicence, but seems that giving the ABS sensor a clean has solved the problem for the time being.

It (the sensor) did have a couple of rings of dark grey sludge on it - what I am taking to be powdered steel from the final drive. Not identifiable as swarf, though - the bits were much too small and powdery, feeling like a smooth paste between fingers. So I'm not overly worried about wear in final drive unit. Will keep an eye on it, though.

 

[Bear]

I've been plagued by RTODs lately. It took a long time but I've finally found a pattern to them. In each case I've been stuck in stop/start traffic for a long time and eventually I get the red triangle and flashing "Brake failure" light, along with losing the servo (2006 GS) on the rear brake (front brake still OK). After the first few times I topped up the fluid reservoirs under the tank then went for a 30 mile run with no problems. I then went to my dealer (65 miles each way, a lot of it motorway) to get the bike checked for fault codes. They reported a low voltage error (the battery was replaced 18 months previously) and, in passing, organised a new FD for me as a goodwill gesture from BMW. All seemed well so we rode from Cheshire to Hythe, stopped for the night then went to catch a ferry from Dover. In the queue, the probelm recurs. 40 miles of French autoroute later I stop for a few minutes. Restarting the engine restores the brakes. It's temperamental for the rest of the day then perfect for the week. We ride back to Calais and the queue to get past UK immigration would put a Soviet grocer to shame. Another RTOD, cured by restarting in the queue for the Dartford tunnel after the M20 at a realistic motorway speed.

Sorry for the long post but it's taken a long time to realise that I have a problem with either the battery being short of capacity, the alternator being unable to keep up with the servo or the servo itself taking too much current for the battery and alternator to keep up with. I have vague recollections of someone posting details (I can't remember where) of the Austrian police having problems with R1150RTs used for escort duty having braking problems. When my present battery dies I'll buy a Yuasa from Halfords or my local Honda shop, but definitely not a genuine BMW item.

 

[Brian ROSEN]

Servo related problems

Firstly it is assumed that you have a 1200GS ( not a 2000GS)
Having had a similar servo model for four years I did realise that the servo takes a great deal of current; this was apparent as the headlight intensity reduced noticeably when the brakes were applied.
(I would not really have noticed if the rear servo was operating or not because I stopped using the reat brake pedal once I became accustomed to the linked brakes.) As your problems seem to occur as a result of queuing in traffic (another irritation that we in France rarely have to put up with) it would seem that you are consuming more electricity than you are generating under these circumstances; (If you use your hazard warning lights for instance, or are holding the bike too long on the brakes or if you have ANY accessories operating,particularly heated grips or clothing. The headlight alone will take a large proportion of your electrical output at low revs.) I think this problem may well be the reason that BMW dropped the servo on the later model.

 

[Pukmeister]

I get the red triangle and flashing "Brake failure" light, along with losing the servo (2006 GS) on the rear brake (front brake still OK).

Do you mean the servo doesn't work at all when pressing the rear pedal, or do you mean it works then stops?

If the latter then relax, the bike is meant to do that by design. The front servo stays on so long as the lever is pulled, but the rear servo cycles on and off to save overloading the battery/alternator when holding the bike on the footbrake only.

 

[Deleted account 210609001]

The front servo stays on so long as the lever is pulled, but the rear servo cycles on and off to save overloading the battery/alternator when holding the bike on the footbrake only.

That's something I've learned today. I'm off to try it out...

 

[Bear]

Do you mean the servo doesn't work at all when pressing the rear pedal, or do you mean it works then stops?

I mean that when the RTOD shows the rear brake is about as much use as a chocolate fireguard (by implication losing its servo-assistance), although the front brake works as normal. I don't hold either brake in dockside traffic as the ground is flat but it was used briefly lots of times on each side of the Channel. Yes the bike is a 2006 R1200GS.