ABS Pump repair

JonB

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Hi
I am trying to fix my 2005 r1200 gs . I have had brake failure warning light and fault code 24972( pressure in rear brake circuit ) .Brake switches have been checked and are set correctly. Braking system has been bled and filters and pressure switches checked on abs pump . I don't want to spend a fortune for a new abs pump and would rather not do a servosectomy . I am wondering if anyone has had any success with ECU testing etc? Any input would be greatly appreciated :bow

Many thanks
Jon:thumb2
 
As no one else has bothered! I'll av a go, there was a post few weeks back around servo repair .consensus was nobody out there that can repair servo unit , but some will charge a fair bit for having a go ,if remeber ecu testing was one of those .HOW EVER one member on here stripped his unit down and gave a nice pictorial guide. Seems there was a build up of crud in certain areas, I think he managed to fix it with some parts from another unit. If you search I'm sure the post will pop up ,wasn't that long ago .😉
 
3bikesnospace
Thanks for the reply I very much appreciate it. I will try and find pictoral and maybe strip the pump myself . I guess not many have had much success.
Thanks again
 
That will have been me that stripped the unit - see this thread:

http://www.ukgser.com/forums/showthread.php?t=448030

Now I was going to update that thread this week when I got home from a trip but I'll update things here.

I finished repairing the unit a while ago and did around 700 miles near home and the failures never came back so decided to call it fixed. Decided this week I was brave enough to take it on a trip down south (I live in Shetland). About 75miles south of Aberdeen on the motorway the brake failure light started flashing. It was on a quiet motorway so hadn't touched the brakes for a few miles. Tried the brakes and it felt like servos were working fine but after another 5 minutes riding it was definitely on to residual braking. Pulled over and switched off ignition for 5 minutes and checked bike over - no sign of brake fluid leaks and all looked normal. Started bike and all warnings gone and everything worked fine and as it should for the last 100 miles of my journey - although was riding much more carefully in case residual braking kicked in. Will be heading home at the weekend - carefully as I've lost some faith again - going on to residual braking at the wrong moment could be catastrophic!

Will check the diagnostics when I get home to see what the actual failure was. However, sort of thinking I might go for a servosectomy now as I don't want to get stranded on a longer journey - 200 miles will not be fun if it goes to residual braking as soon as I set off for home.

However, I was kind of pleased with myself for getting it working and I do quite like the servo brakes - so maybe will try to figure out anything I can do to fix it again - I did get nearly 1000 miles before getting this brake failure this time.


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Hi
I am trying to fix my 2005 r1200 gs . I have had brake failure warning light and fault code 24972( pressure in rear brake circuit ) .Brake switches have been checked and are set correctly. Braking system has been bled and filters and pressure switches checked on abs pump . I don't want to spend a fortune for a new abs pump and would rather not do a servosectomy . I am wondering if anyone has had any success with ECU testing etc? Any input would be greatly appreciated :bow

Many thanks
Jon:thumb2

I read your post but was unable to add anything constructive so I didn't bother. This site is full of stories about unsuffical attempts to repair servo units. You don't want to do a servoectomy and a new one is thousands. There are many reasons for failing and it's a very complicated system both the unit itself and the various goblins attacked to it. If I could give you advice do a removal. It will end up totally pissing you off. It's your brakes. I've never heard of a problem with a PROPER job. JJH
 
Hunda 67
Very interesting post and thank you for the info . I reckon I will have a go at stripping and cleaning the pump . Very very much appreciated!
Cheers
Jon
 
Having never ridden a bike with servo assisted brakes,
I can't tell what they should be like.

What I can tell you is a non abs / sevectomised bike stops fine.

Servo/ abs won't change the laws of physics. If your going in too fast,

Nothing you have on the bike will stop you any quicker.
 
All information greatly appreciated gents. I am hopefully going to attempt a strip and clean after the bank holiday. I guess I have nothing to loose and as JJH as mentioned I can always go down the servosectomy route .
Many many thanks.
 
That was my thinking when I stripped mine down - nothing to lose. I will certainly be interested in how you get on and what you find.

For me personally I'm just trying to keep the bike as it was built - yes I am sure the brakes are just fine after a servosectomy but I quite like the servos.

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That was my thinking when I stripped mine down - nothing to lose. I will certainly be interested in how you get on and what you find.

For me personally I'm just trying to keep the bike as it was built - yes I am sure the brakes are just fine after a servosectomy but I quite like the servos.

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I also want to keep the bike original and would rather have a go at fixing the pump first. If all else fails I will go ahead with the servosectomy .
Will keep you up-to-date with what I find .
Thanks again for the info and pics . Very much appreciated!
 
No problem. I will also post here if any failures on journey home and anything I find when I take a look next week.

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I quite like the ABS Happily could do without the Servo assist if I could retain ABS

I have worked on these bikes since the First 1150RT were released in 2003

I hate the complexity of the system and the fact that you have no fall back to standard brakes if they fail

Having watched Hunda67's thoroughness in his thread on the rebuild? I would say If you cannot afford a new servo? Go straight for servo removal End off I have seen so many variations of servo failure The only ones I know still okay were the ones that I did ANNUAL full brake fluid flushes One at 98K just recently Only 26K on my 1200GS

They are just too much of a toss of a coin to be risking your life on a Maybe / if / Possibly !!!
 
Dr Farkoff could be right - mine is the only experience I've had with these brakes but sounds like he's seen loads that have had problems. I'll certainly be paying attention on my 200 miles tomorrow!

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JonB I know you say that you don't want to do a Servosectomy but in my experience the brakes end up being better after removal of the ABS servo unit. I'm talking about the earlier models <2006/7 I think. Mines a 55 plate and I do trips abroad Pyrenees/Alps etc and I didn't want to have my ABS/servo system give up on me mid trip. So I did a sevosectomy last year and on a run through Spain/Pyrenees/France the brakes were superb, more feel less grabby. I installed new Brembo blue pads on the front (organic not sintered) and the bikes fine. OK i don't have ABS anymore but as I ride to enjoy the views and not a speed merchant I can't ever recall having actuated my ABS in 7 years of riding my GS! Plus you save a load of weight, that ABS module must way a good few kilos.

Just my experience.
Mark
 
Back home now - did my 200 miles and the brakes worked just fine and no faults popped up which was good. However, I was riding cautiously just in case the bike went onto residual braking which kind of takes any of the fun out of the ride (and someone will always go into that big gap you are trying to leave between yourself and the vehicle in front).

So plugged the GS911 in this morning and these are the faults that are in the history (history was cleared after rebuild of ABS unit 2 months ago) - all faults were not present now:

25165: Internal Control Module Error - main processor reset due to indervoltage - battery is fairly new and good - without a timestamp impossible to know when it occurred but probably nothing to do with brake failure warning coming on whilst cruising on motorway.

24951: ABS motor rear, defective - I assume it is talking about the rear whizzy motor for the servo part of the brakes. Don't know how the system determines a defective motor but motors whizzing away just fine for both front and rear brakes.

24971: Pressure in front wheel circuit to high - this is the fault I thought was probably closer to the what the actual problem is.

So I had a look at the realtime data:



Hmm now it's getting strange :confused:

From the realtime data it looks like the front wheel circuit is too low and not high although there are no faults currently present. I compared with the realtime data I noted a couple of months back and the front wheel circuit was about 16 Bar back then compared with 4 Bar now.

Also this time the Brake Sensor Drift Test refuses to run this time:



and I am assuming this is because of the low pressure in the front wheel circuit.


So my thinking for now is as follows:

1. I still have some air in the system (front wheel circuit) and the brakes need bled again.

2. There is another defective pressure switch - like this one I already replaced:


3. One of the pressure relief valves is stuck open - there are 2 of these but I don't know if they release pressure on the control circuit or wheel circuit side.


So right now debating with myself to either run through the above things and hope I can fix it - after rebuilding and cleaning the unit the brakes have worked better than they have for years - stuff like brake failure warning light going out with 10 feet of moving off which in the last few years would always take a lot longer - or just giving up on the whole thing and going for the servosectomy :confused::confused::confused:

There was some satisfaction in getting it all working again but I don't want the worry of riding the bike like a pussy just because I'm always worried the brakes are going to fail :nenau

Are there any servo assisted bikes out there with reliable brakes or am I fighting a losing cause :confused:
 
Got some time this afternoon so decided to bleed the system again. Bled the front circuits enough to flush a complete fluid change through - no air or crud came out.
Since I had the tank off for doing this I checked the whole bike carefully for leaks but couldn't see any.

Connected up the GS911 again and still only 4 bar in the front wheel circuit - other 3 circuits between 18 and 20 bar.

So all I can think of doing (if I want to keep the servo's and ABS) is to strip the unit down again - maybe a pressure switch or a dodgy seal or a blocked oilway :nenau

When riding the bike the brakes feel as they should and the bike doesn't flag up any errors. I would have thought that because the GS911 refuses to do the Brake Sensor Drift Test because of the "static value of one or more sensors is out of range" (and I'm guessing it doesn't like the 4 bar) then surely the bike itself should give a brake failure indication :nenau

Be intrested now how you get on JonB.
 
Removed the two pressure valves from top of unit this evening - both seemed to be ok.

So decided to remove the unit - my thinking is the 4 bar reading must be caused by a faulty pressure switch or a blocked oil way in the unit.

Will strip the unit down later this week when I get some time but still seriously thinking of doing a servosectomy as it's a lot of hassle getting the unit out and even more putting it back in and bleeding everything for it all to go faulty again.

Anyone on here with more experience of working on these brakes opinions appreciated 😀

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