Brake Failure after replacing Master Cylinder

NeilH

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I will actually post how I replaced the master cylinder on my other thread, perhaps in the coming days.

Now before I replaced the master cylinder I didn't have the brake failure light on at all, So I think it's something I have done that's perhaps triggered it.

1. Master Cylinder replaced
2. Brake pads replaced
3. Brakes bleed
4. ABS bleed

First ride.....brake failure.

Fault Codes : 2

24048 : Pump motor defective
Currently present : YES

24049 : Power Supply to Pump motor faulty
Currently present : YES

Battery voltage was around 12.8v.

Did I mess something up or was it bad luck?

I have a GS911.....so I can do other things! (Not sure what yet)
 
I replaced the Master Cylinder because I noticed one of the treads was stripped while doing a routine service and I believe fluid had probably leaked out.

I have never called upon the ABS

https://www.ukgser.com/forums/attachment.php?attachmentid=468015&stc=1&d=1599309140

I might give it a hammer test first, but I didn't want to have to strip it down to replace the bushes or at least clean the bushes if I had overlooked something else.

If I managed to do the ABS bleed did that not use the motor?
 

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Apart from administering the hammer, which sounds like a somewhat temporary solution, IIRC someone in the hexcode link suggests disconnecting the ABS & applying 12v to the pump motor. Then, if no joy, it's down to checking the brushes.

Look, I know is disappointing but as I see it, with those codes, the problem is defined. By your own admission, the ABS pump has never been called upon or exercised until now.
 
This is how I ended up removing my front brake master cylinder, the manual says remove all the plastic and tank then unplug the heated grips as the connector is under the tank.

I didn't do that.

1. cut the cable ties that keeps the heated grip cable to the loom, there is only a few to cut down as low as you can get.
2. Remove the accelerator cover
3. Remove the screws that hold on the front switch
4. Remove the under plate
5, Empty the front brake cylinder (I didn't bother - but you want to keep the brake fluid off your paint work)
6. Detach the front brake line (Be careful regarding brake fluid spillage)
 

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7. Remove the handler bar end
8. Remove the accelerator cable
9. Undo the fixture holding on the Master Cylinder. Note how my brake fluid had been leaking out of the master cylinder and destroyed the paintwork
10. Remove the right handlebar - this gives you the clearance for the heated grip cable you need so you don't have to remove the petrol tank.
 

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11. Slide of the heated grip being careful to feed the cable through the hole in the handlebar
12. Remove the master cylinder
13. In my case repaint the handlebar
14. Slide the replacement or fixed master cylinder back onto the handlebar
 

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15. I used a socket to slightly open the clamp so it didn't destroy the paintwork.
16. Basically reverse the procedure to get everything back

Tip...before you tighten the master brake cylinder clamp put on the heated grip and handle bar end and make sure you have free movement of the throttle!

Don't forget to torque the handlebar once refitted.

Next.

Here is a good opportunity to put in new front brake pads (I did that too)

17. Top up the master cylinder
18. Bleed the brakes including the master cylinder, when it comes to the calipers do the furthest one from the master cylinder first.
19. Next use the GS911 or other system to do a bleed test on the ABS
20. Curse when you find out your ABS is poked and leave that for the next job!
21. Curse again when you found you put all this on the wrong post :anger:

All in all the above was a fun job, it took longer for the paint to dry than anything - a friend to help bleed the brakes would have been useful as the one way valve and pipe I bought was rubbish, bleed the brakes the old fashion way.

Job done!
 

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Lets go back to the brake failure light, this is red text not a triangle symbol.

I have removed all the plastic and tank and getting ready to remove the ABS, then I remembered that there are other functions on the GS911 other than bleeding brakes.

So I plugged it it, ran the software.

Cleared all existing error codes.

I performed 6 tests, pump, changeover valve, front inlet, front outlet, rear inlet and rear outlet. The pump ran! the other tests you just seemed to hear a "click"

After I checked and there are no error codes.

So is this to do with something else?
I've not taken the bike out again yet.

What is involved with the startup check? must the front wheel rotate a certain distance?

What else can it be?
 

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