GS-911 seems to be turning ABS servos off

[BeenAround]

Hi all,

Last year I had the harrowing experience of having to replace the iABS Gen I unit in my 2005 BMW R1200GS.  That is when I bought a GS-911 to assist with diagnosis.  It didn't assist with the cost of having to replace the ABS unit at a cost of AUD3,000 landed here in Australia from A&S in California.  The BMW Motorrad Australia price was AUD3,843 - robbing so and sos.  Anyway, I battled through and replaced the bloody ABS unit and then went through hell bleeding the system.  And finally successfully performed bleed test on GS-911.

Then, when back on the road (actually on a National Park track in the middle of nowhere), the rear flex brake line exploded at the rear swage.  A mechanic at Wacky World told me that all flex hoses should be replaced every 6-8 years.  That makes sense, but I have not found any recommendation by BMW to do so.  That the flex hose failed at the swage and sprayed boiling brake fluid all over the final drive housing and swing arm, that perhaps explains why I had so much trouble bleeding the rear wheel circuit.  But it did bleed up in the end.

I got a set of hoses made up by HEL for a total price that just exceeded the OEM price for one of the 5 flex brake hoses.  That meant the brake system (and the clutch for good measure as I also replaced the clutch line) was drained, re-filled and had to be bled again.  The brakes and the ABS work just peachy.  But when I tried to do a bleed test, the GS-911 seemed to switch off the ABS servos so I could not do the test.  This happened right after I had downloaded the latest GS-911 software.

Has any other iABS Gen I sufferer had this problem.  i have emailed Hexcode and am waiting for a response,

Regards,
BeenAround

[StephanT]

I don't see any mail from you and no HelpDesk ticket.

Pls send a mail to the Helpdesk (see our contact us page) and give us a little more info...

have you tried the release version as well?

best
Stephan

[kobus]

The switching off of the servos by the ABS during the bleed test is expected and correct behaviour.
The instructions is to pull (not pump) the brake lever until it reaches green on the display and keep it there until instructed to let it go (it takes quite a bit of strength to do this though).
I would imagine if the ABS left the servos on, then there would be feedback and measuring the correct pressure will not be possible.

[marchyman]

The servo assist can mask a bad bleed/flush.   The only way to know that it is good is to check without servos. Before the GS-911 I used to test my bike post bleed by killing the ignition on a mostly straight and flat road near my house and see if I could stop the bike using only residual breaks.   It's good to find such things out before putting the bike completely back together.

When doing the GS-911 test make sure the brake lever is adjusted to give you maximum lever throw and if necessary USE TWO HANDS.   It is not an easy test to pass as you not only have to squeeze hard you have to hold the squeeze in a certain range for a period of time.   Two hands can make the job easier.

[BeenAround]

Hi all,

Thank you for your responses. 

I note what you say about the GS-911 deliberately turning off the servos to conduct a bleed test.  But that is not how the GS-911 conducted the belled test before I downloaded the latest (1303.3) software.  The last time I did a bleed test, the servos were definitely operating.

I will give it another go.

Thanks again,
BeenAround.

[kobus]

It's not the GS-911 that turns off the servos, it's part of the bleed test procedure (initiated by GS-911) of the ABS that turns off the servos. If this did not happen before (I note that you replaced the ABS at some stage) it is because there was something wrong with the ABS or it had different firmware on - or it was a different ABS type.