"brake failure" warning after full bleed.

Smiffypr

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Hello everyone.

The bike is a 2005 R1200GS with servo/ABS brakes. It has sat unused for a year. So the other day I got it out of the garage and gave it a wash and a quick check over then booked an MoT. Yesterday I went for the Mot and soon noticed that the brake failure light and red triangle were lit. The front brake worked fine, but the back brake hardly did anything and it failed the MoT on an inefficient back brake.

I searched the www and it seems to be common when these bikes have sat for a while and "everyone" said to bleed the brakes.

I started by bleeding from the rear calliper. what came out was dark brown, but the level in the reservoir didn't go down, so I looked more closely at the workshop manual (RepRom) and found that the fluid that I was getting out comes from an internal reservoir in the ABS unit.

So now I have topped up the then empty reservoir and bled everything until I got clean, bubble free fluid out of all four bleed points. I thought that I should also check the front brake fluid too. That came out clean, but I think I might have let the ABS reservoir get too low at one point so I bled the three points on the reservoir as well as the two front callipers.

Now, when I move off the warnings go off, but once I apply either brake any more than gently, the big red triangle and brake failure light up again and stay on until the ignition is turned off. Both brakes, and the ABS seem to be working, but I'm just testing up the back alley as the bike has no MoT or tax.

With the bike stationary, when I turn the ignition on I get the yellow triangle and "brake failure" as normal, but when I apply either brake hard the triangle turns red, but returns to yellow when the brake is released.

Can someone confirm if this is normal or does the triangle going red indicate that the problem is being detected at that point?

I'm hoping that letting the fluid "rest" overnight and a re-bleed tomorrow might fix it, but any other suggestions appreciated.

Smiffy
 
Off the top of my head, there is a bleeding order to follow, which I did on mine a couple of times.
Equally, according to a most distinguished gentleman on here, "just use the servo to push it through in the traditional manner" - that works too.
I think.
 
I think I did it in the correct order, including going back to the first one on the ABS unit.
I will check this evening though.
 
I have the same issue on a 2006 bike with ABS& Servo, almost back home after a 50 mile first ride since October, I had the same indication, stopped turned everything off and on again, lights went off as normal but soon as I pulled lever came back on, tried brakes and everything seems normal and bikes brakes as usual, had a problem with sensor on rear wheel a while ago which affected speedo, everything works this time so did some searching, ow brake pads is a possible cause, found my brake pads were all getting down to about 2mm so fluid is lower in system, so new pads to be fitted tomorrow and then see what happens.
Following this with interest, hopefully help me as well.

Al.
 
When I looked at the workshop manual again, it turned out I hadn't bled the right nipples at the right time.

This afternoon I have bled everything again, used well over half a litre of fluid.
Bleeding the front calipers, I pull the lever, the servo pump runs, I open the bleed nipple and the fluid flows and continues to flow due to the servo pump running.
Doing the rear caliper, when I open the bleed nipple, I get a small amount of fluid as the pedal sinks, but although the servo pump is running, no more fluid comes out. I suspect this is a fault.

With the bike stationary, when I switched the ignition on and waited for the display to cycle through it's stuff, I had the neutral light and the brake failure words flashing slowly (as normal). Applying the rear brake gradually, the servo pump ran and the red triangle flashed up briefly. Applying the front brake, once it's on hard, the red triangle comes on and the brake failure words flash faster. (The rear wheel will still turn at this point).
But, if I apply the back brake fully, then applying the front brake, no red triangle.

So what I think is happening is, the back brake servo pump is running but not generating any pressure, so when the front brake is applied it tries to build up some pressure in the rear brake too, but this fails. When the back brake is already applied, it already has sufficient pressure, so the warning doesn't come up.

I will probably leave it as it is and hope it passes the MoT, which it should because the rear brake is now working, and hope that he accepts that the warning comes up because only one wheel is turning on the brake tester.

Depending on why the rear servo pump is not building pressure, it may start to work with use (and fresh fluid).

So, does that all make sense?

And, has anyone ever taken the ABS/servo unit apart and know what the pumps are like?
 
Listen Carefully! For I will say this only Once!

It Has All been tried before Its a CRAP unit! They are Schite

They are usually Not repairable! Junk it and move on!

You have two options

Remove ABS brain from the Servo Unit and seal it up and then plug it back in the loom and secure it to the bike

Repipe the brakes to Non ABS style

And split the clocks and cover or paint the LED warning lamps

OR This https://www.ukgser.com/forums/showthread.php/549455-Servo-ABS-replacement-Possible-new-option

Plug and play

Honestly You will have your bike back on the road much quicker this way
 
There is a very precise system for bleeding and changing the fluid on your bike. And sadly, you've messed it up. It sounds like you've drained the ABS pump.

You need to start again following the correct procedure. And you also need to fill the pump with brake fluid using a special bottle which screws into the pump for this procedure. (Or make one).
 
Yes, I understand that now and have filled and bled and the entire system is full of clean, air free, brake fluid.
 
DrFarkoff, Do you think that my conclusion that the rear servo pump is not generating pressure is correct?
Also, as it sounds like you have been inside these units, is there a weak link in the way the motor drives the pump?
 
DrFarkoff, Do you think that my conclusion that the rear servo pump is not generating pressure is correct?
Also, as it sounds like you have been inside these units, is there a weak link in the way the motor drives the pump?

The system is just weak and fragile I have pulled them out as early as at 3 weeks old when at the dealership back in 2003 with the first twin sparks came out with it

The only thing that seems to save them is to completely the 4 circuits every year and even now my preference is to tell folks to bin them IF they are seeing issues

You Do NOT want to go into residual braking mode when you are out playing

I can't stress enough for the last 15 years people on here have been trying to fix them and most folks are very happy with the non servo brakes that they get after kicking the system into touch (no matter how long it takes for them to realise it's the safest way )!
 
Is the pump motor working when you're applying pedal or lever effort ? As you know, you can easily hear it.
 
Yes. pump motors work, front pump actually pumps fluid out of calliper bleed nipple, rear one doesn't.

Front should pump out both nipples ! They are linked brakes! Honest Smiffy you are chasing a red herring You will go around in circles

Its either £2k for BM to fit one or about £500 to get it overhauled IF the place can even still be bothered doing them

Someone did code the ABS unit out of the Central Electrical unit a while back using some diagnostics and moving a couple of pins

But painting over the ABS LED's does the same thing :aidan

Feel Free to read all the tales of woe here about Post 41 is where Steptoe breaks the news about leaving the Servo box connected to the Loom and ditching the rest of it I know they are 1150s But its the same servo assisted Integral ABS unit

https://www.ukgser.com/forums/showthread.php/232002-Simple-NO-COST-servo-removal-of-1150-IABS-system
 
Front should pump out both nipples ! They are linked brakes! Honest Smiffy you are chasing a red herring You will go around in circles

Its either £2k for BM to fit one or about £500 to get it overhauled IF the place can even still be bothered doing them

Someone did code the ABS unit out of the Central Electrical unit a while back using some diagnostics and moving a couple of pins

But painting over the ABS LED's does the same thing :aidan

Feel Free to read all the tales of woe here about Post 41 is where Steptoe breaks the news about leaving the Servo box connected to the Loom and ditching the rest of it I know they are 1150s But its the same servo assisted Integral ABS unit

https://www.ukgser.com/forums/showthread.php/232002-Simple-NO-COST-servo-removal-of-1150-IABS-system

I'm not chasing a red herring, I'm trying to find a solution which will keep the ABS. From what I can gather, there isn't a way of dumping the servo function but keeping the ABS, so I would ideally like to fix the system which has managed to work for 16 years, but failed because the fluid hadn't been changed.
As the rear servo motor runs, but it doesn't generate pressure, (or change it's tone when there is pressure in the system) it seems very likely that the motor and pump are disconnected. That's got to be easy to fix.I've got a lathe and mill if I need to make anything, but I don't want to spent thousands or loose the ABS.
 
I'm not chasing a red herring, I'm trying to find a solution which will keep the ABS. From what I can gather, there isn't a way of dumping the servo function but keeping the ABS, so I would ideally like to fix the system which has managed to work for 16 years, but failed because the fluid hadn't been changed.
As the rear servo motor runs, but it doesn't generate pressure, (or change it's tone when there is pressure in the system) it seems very likely that the motor and pump are disconnected. That's got to be easy to fix.I've got a lathe and mill if I need to make anything, but I don't want to spent thousands or loose the ABS.

OR as normally happens with these piece of schit units If they are run out of fluid in a circuit, when someone who hasn;t done the fluid change before does one

Quite often the clearances in the hydraulic pump chamber get ruined, So it can't generate the pressure as before!

Don't you think that after 18 years of working at them in a professional capacity, If I had found a fix? I would have recommended that fix??

Well actually I did, I recommend taking it out or replacing with new or refurbished

If you had a 2006 on Non Servo with sticky brushes, as they seem to get, I would recommend fitting the whole motor part off a Mk9 Fiesta ABS unit which really works quite well

Have fun and Good Luck with it Let us know how you get on :thumb :thumb
 
I have to agree with Drfarkoff.

He's been working on these units longer than me, but from my time at the dealerships from 2012 onwards, we were getting loads of these generation ABS bikes coming in with ABS fault lights. Like everyone else, we looked at solutions to fix them. Have you had the fault codes read even ??? A dealer can do a pressure test.

I've been swapping these pumps, bleeding and removing them for ten years now. The integral ABS pump on your bike is a brick made of solid terds. Now in my own workshop I give the same options to my customers. Delete the ABS completely, fit a reconditioned unit or get anally raped by BMW for £1200 (or more) for a new unit.

That it has lasted 16 years is a miracle.

It's obviously your choice how much you want to spend on your bike. And you obviously want to keep your ABS (I don't blame you). But after 16 years, you need to accept that you need a new or reconditioned pump to make that happen.

I really do appreciate your approach here. You like fixing things and you want to fix your ABS pump. If you manage what thousands of other professionals have failed to do in your shed at home then please share with us all how you did it.

My advice would be to remove the pump and send it to these guys for diagnosis or deconditioning.

https://www.ecutesting.com/categories/abs-pump-modules/
 
If it can be reconditioned, then I should be able to do it myself. The problem in many cases is that the parts needed are not available.
The suggestion that wear in the actual pump could be the problem makes sense, the fluid that came out of that circuit was very dark brown. (The fluid in the other 3 circuits was slightly yellow, obviously much newer.)
I've emailed ecutesting.com to ask if they do repair this module as their website only says they cover the 2008-2019 R1200GS, I've also asked if they can supply parts.
 


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