ABS Problems After Changing Brake Hoses

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pats.piercing
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ABS Problems After Changing Brake Hoses

Postby pats.piercing » Wed Nov 15, 2017 2:56 pm

Hi,

I have just changed the front brake hoses on my 1995 R1100RT and now the ABS lights will not go off. I had a lot of trouble bleeding the brakes and had to replace all the fluid and bleed from the ABS unit and also the calipers. I finally got a decent feel on the lever and thought that all was good.

However on test riding the bike the ABS lights do not go off.

When I turn the ignition on they flash together

When I ride off, when I reach about 10 kph the lights start to flash alternately and stay like this.

The brakes seem to work ok but I have not tried locking them up.

I have tried resetting the ABS unit but it makes no difference.

Any ideas

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Galactic Greyhound
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Re: ABS Problems After Changing Brake Hoses

Postby Galactic Greyhound » Wed Nov 15, 2017 5:02 pm

When I ride off, when I reach about 10 kph the lights start to flash alternately and stay like this.

This indicates that the final stage of the ABS2 test sequence by the ABS Controller has failed.

The most likely cause of failure is no signal from a wheel sensor when you ride off.

As you have been working on the front brakes, Inspect the FRONT wheel sensor and its cable very carefully for any damage.
Also check the sensor/tone wheel gap is correct.

You can measure the resistance of the sensor from its connector which IIRC is up near the top of the RH fork slider - follow the cable back to find the connector.

The sensor resistance should be about 135 Ohms.
The cable can fracture internally around the bottom yoke area so flex the cable when you take the resistance measurement to make sure the fault does not go on and off with movement.

The rear sensor is the same resistance and its connector is up on the RH top frame tube under the pillion seat IIRC.

Otherwise, you need to read the Fault Code from the 3-pin Diagnostic Socket under the pillion seat on top of the rear mudguard.
Unplug the Blue cap to access the connector pins.

Motobins do a very useful 'Fault Code Reader' for the ABS2 system which I would recommend you use rather than try and count the 'spaces' in the code stream which can be difficult.
The Motobins Reader is around £25.

The ABS2 system is very robust and reliable - if the ABS fails you still have full hydraulic braking and only lose the ABS function so the bike is still safe to ride while remembering there is no ABS.

I'll post some more info later this evening when I get onto my laptop.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
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pats.piercing
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Re: ABS Problems After Changing Brake Hoses

Postby pats.piercing » Wed Nov 15, 2017 5:18 pm

Great, It is possible that I have dislodged the wheel sensors because I had the front calipers off to push the pistons back when I was bleeding the brakes.

I will have a look tomorrow.

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Re: ABS Problems After Changing Brake Hoses

Postby Galactic Greyhound » Wed Nov 15, 2017 7:10 pm

The sensors are fastened in position so it's not possible to move them unless the fixing screw is removed.

It's more likely to be a damaged/faulty front sensor cable or the front sensor gap has been knocked out of correct clearance.

The sensor/tone wheel gap is set by inserting/removing special shims.

Normally when you get an ABS failure it is usually quicker to find the problem by first checking the Fault Code, but given the work you have done, checking the front sensor resistance and sensor gap is a logical and fairly quick test and may show up the problem.

If the sensor, cable and resistance looks OK then you need to read the Fault Code.

The Motobins 'Fault Code Reader' is: 'Motronic Diagnostic Tester', Motobins Part Number: 95540
Using this tool you just count the Fault Code FLASHES which is easy and minimises the risk of error.
Motobins link, Part Number 95540: https://www.motobins.co.uk/displayfinal ... ch=1&go=GO

Otherwise, if you just use an Analogue (needle) Voltmeter or an LED to count the Fault Code directly from the Diagnostic Socket you have to count the DIPS in the analogue Voltmeter needle or the OFFs for the LED between the start and end sequences of the code stream to determine the Fault Code which is more tricky and prone to error.


Here's some info worth reading beforehand:

ABS Faults by Anton Largiader (see ABS2): http://www.largiader.com/abs/absfault.html

_______________

ABS2 Wheel Sensor Measurement.txt Issue: 02/07/2017

Author: C. Mungall
Date: 03/07/2014
Ref: viewtopic.php?f=14&t=19838&p=127909#p127909


The R1100 Oilhead ABS Sensors are just a coil of wire wound round an iron core (Inductive Transmitters).
The current passing through the coil creates a magnetic field which gets modulated by the Tone Wheel (ribbed metal disc) and this produces a signal in the coil which can be decoded for wheel speed - in this case, decoded by the ABS Controller.

There are some useful sensor tests you can do such as:

1. Sensor resistance.
2. Voltage being applied to the sensor connector (with the sensor connector disconnected).
3. Current flowing through the sensor with the sensor connected.
4. AC voltage produced by the sensor when a magnet is passed rapidly over it.


Sensor Resistance = 135 Ohms.
Voltage (Ignition ON) = 6.68V.
Current (Ignition ON) = 18.9 mA.
Sensor - Tone Wheel Air Gap = 0.50 - 0.55 mm.


CURRENT FLOW TEST:

I believe that the ABS Control Unit Initial Check works by monitoring the CURRENT through the sensor. If the current flow is within specification then the Initial Check of the sensor is passed OK.

Here is how I measured mine:

1. Disconnect the sensor connector.
2. Note how the female socket connector (loom side) engages with the male pin connector (sensor side) - there is a long plastic indexing piece on the female connector that engages into a slot in the male connector so that the connector cannot be connected the wrong way round. Note that the +6V supply socket/pin (Red wire) is nearest the indexing pieces. The other socket/pin furthest
away from the index is the negative (ground) pin.
3. Using a short length of 25 swg insulated wire (circuit wire), insert one bared end into the sensor loom-side female connector +6V supply pin socket (red wire goes to this).
4. Connect the other bared end of this wire to your meter positive test lead.
5. Using a 1mm drill, wind one bared end of a short length of 25 swg wire round the drill and remove the drill (this wire end will slip over the male pin (ground) in the male connector to make connection).
6. Insert the wire at 5 above, over the male connector (sensor side) ground male pin (furthest from the index) to make contact.
7. Insert the other end of this wire into the female connector (loom side) ground socket pin to complete the ground wire circuit through the opened up connector.
8. You are now ready to measure the current - set your meter to be able to read around 20mA.
9. Switch the Ignition ON.
10. VERY CAREFULLY, with the meter negative test lead, probe the male connector (sensor side) +6V pin nearest to the index - this will complete the circuit through the sensor and a current reading of around 19 mA should be obtained. Be careful not to short onto the other male pin.
11. Switch the Ignition OFF.

When I restored everything back to normal, I had to do a Reset to clear the Fault Code 4 - I found that it reset after holding the ABS Switch down for just 30 secs and not the 2 minutes as previously stated.


EXAMINATION OF FAILED SENSORS:

Two R1100RT ABS sensors, one front & one rear, were examined on 23/09/2014.
Both of these sensors did not show continuity from the connector through the sensor.

Front Sensor: This was found to have failed due to wiring fracture within the Black cable from the connector to the sensor. There are two wires in this cable which are coloured Brown and Black.
Both of these wires were found to have fractured approximately 600 mm from the sensor. This places the fracture point about the bottom yoke (which joins the fork legs) and the Right Handfork leg. It is likely that the turning motion of the forks at this point is the cause of the fracture. The sensor cable should therefore have some slack in this area to allow it to flex comfortably and not be restrained too tightly that a bending motion is concentrated at one point in the cable.

Rear Sensor: This was found to have failed due to wiring fracture within the Black cable from the connector to the sensor. There are two wires in this cable which are coloured Brown and Black.
Both of these wires were found to have fractured where the cable entered the sensor. There is no continual bending motion of the cable at this point and it is likely that the fracture occurred due to mis-handling of the sensor cable during rear brake servicing.


TESTING OF SENSORS:

As well as the DC resistance test and Current Flow test through the internal winding, a magnetic test can be done to further prove a sensor is working.

Continuity Test: Connect an Ohmmeter to the sensor connector, a reading of 135 ohms should be obtained through the sensor winding.

Current Flow Test: See procedure at start of article. The current flow through the sensor should be 18.9 mA.

Magnetic Test: With a Voltmeter set to read around 4 volts AC connected to the sensor connector, pass a magnet rapidly to and fro across the face of the sensor. The Voltmeter should indicate a voltage of around 0.2 V AC.

_________________________
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Jaythro
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Re: ABS Problems After Changing Brake Hoses

Postby Jaythro » Fri Nov 17, 2017 5:07 pm

Did you by any chance have the front wheel out?

I have know a friend fitted his wheel the wrong way round and the primary checks are okay but the pulse ring or tone wheel was on the other side from the sensor! True Story!

It sounds more like an Airgap problem "Or" is your sensor ring very rusty at the minute? If it is, the Rust prevents a clear signal for the ABS controller

Basically on start up it has a circuit for the ABS sensors but on moving off the controller is not seeing similar signals and failsafes the ABS to "off" to save an Accident occurring

rust on a pulse ring ABS sensor covered in Rusty particles or Pulse wheel not even there is also a cause
"Put your Ass on a motorcycle and ride with an attitude and the "Grim Reaper" will ride in your shadow!"

Islandmagee in case you're interested?

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Re: ABS Problems After Changing Brake Hoses

Postby pats.piercing » Sat Nov 18, 2017 5:51 pm

Been out for a ride on it today and sometimes the abs lights go and and sometimes they don't. If they don't go out I need to stop the engine, restart it and then they go out when I pull away.

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Re: ABS Problems After Changing Brake Hoses

Postby Galactic Greyhound » Sat Nov 18, 2017 7:29 pm

As long as the ABS Lights are flashing TOGETHER before you ride off and only start flashing ALTERNATELY when you are riding, then this points to a high probability of it being a wheel sensor problem.

What is the air gap between the front wheel sensor and the Tone Wheel (Pulse Ring)?
[Sensor - Tone Wheel Air Gap = 0.50 - 0.55 mm.]
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: ABS Problems After Changing Brake Hoses

Postby pats.piercing » Sun Nov 26, 2017 8:03 pm

Sorry for the delay. I have not checked the gap yet as I have not got the right size feeler gauge. I should be borrowing one from a friend on Tuesday. Been for another rideout today though and have noticed that sometimes the ABS passes the self-test and the lights go out and sometimes it doesn't. If I turn off the ignition and then turn it back on it usually passes the self-test and all is fine

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Re: ABS Problems After Changing Brake Hoses

Postby Galactic Greyhound » Sun Nov 26, 2017 10:09 pm

Sorry for the delay. I have not checked the gap yet as I have not got the right size feeler gauge. I should be borrowing one from a friend on Tuesday. Been for another rideout today though and have noticed that sometimes the ABS passes the self-test and the lights go out and sometimes it doesn't. If I turn off the ignition and then turn it back on it usually passes the self-test and all is fine

What self-test are you writing of?

There are THREE main ABS Self-tests on your R1100RT with ABS2:

1. The First self-test is when the Ignition is switched On (engine NOT started) - included in this check is the CONTINUITY of the wheel ABS sensors.
If this self-test is OK, then the TWO ABS lights will continue to flash TOGETHER.

2. When the engine is started, the ABS Controller monitors the Battery voltage which, even on a good battery, can fall as low as 9.0v when the Starter Motor is engaged.
Unfortunately, the designers of the ABS2 system set the 'Battery Voltage Fail' trigger point too high with the result that an older but perfectly servicable battery may fail this check especially first thing on a cold morning.
The result is that the ABS Controller senses the Battery Voltage dropping below its monitored trigger point and registers an 'ABS Fault' condition by flashing the two ABS lamps ALTERNATELY when the Starter Motor is engaged.

If this happens to you, then continue the engine start procedure and ride off for about 1 - 2 miles before stopping and switching the Ignition Off - this automatically resets the non-permanent 'Battery Fail' condition in the ABS Controller.
The annoying flashing ABS Lights can be stopped from flashing for a few minutes by pressing the 'ABS' Switch on the dash panel which will extinguish one but leave the other On as a reminder that the ABS is not 'Active'.

After stopping, switch the Ignition back On and restart the engine.
With the Battery having been warmed up by charging over the previous 1 - 2 miles and the engine oil warmer, the Starter Motor will not put such a strong demand on the Battery as when it and the engine were cold.
The Battery voltage therefore, will (hopefully) not now fall below the critical trigger level allowing the ABS Lights to remain flashing TOGETHER after starting.

3. When the engine is running but BEFORE riding off, the two ABS Lights should be flashing TOGETHER indicating that the ABS is ready for its final 'self-test and set' procedure.
On riding off, the wheel sensors begin to send impulses to the ABS Controller which checks that the impulses are being received and that they are being received at the same rate i.e. the front sensor impulses are transmitting at the same speed as the rear sensor impulses indicating that both wheels are rotating at the same speed.

If that self-test is OK, then the ABS Controller tests that the ABS Modulator front and rear brake pressure relief pistons are functioning - you will hear a loud 'Chirrup - Chirrup' when this happens at about 5 mph.

If this final self-test is OK, then the ABS Controller will set the ABS2 System to 'Active' indicated by the extinguishing of the two ABS Lights.


You therefore need to clarify in your post which 'Self-test' you are referring to.
You should also buy your own set of Feeler Gauges from Halfords or the like as you will need them for servicing the bike. :-k :smile:
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: ABS Problems After Changing Brake Hoses

Postby pats.piercing » Sun Nov 26, 2017 10:39 pm

It is the final self test that it sometimes fails, and yes I will be getting some new feeler gauges from Halfords when we get back to the UK later this month.

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Re: ABS Problems After Changing Brake Hoses

Postby Galactic Greyhound » Mon Nov 27, 2017 12:25 am

It is the final self test that it sometimes fails, and yes I will be getting some new feeler gauges from Halfords when we get back to the UK later this month.

Sensor gap check first - front AND rear! :grin:

Also check that the Tone Wheel is clean and not damaged.

If that is OK, there is the possibility of a faulty sensor/wiring which is OK intermittently but going open-circuit with vibration or movement (particularly the bars).

It is probably better waiting till this fails completely as it will make the faulty sensor easier to find - measuring from the connectors, a sensor should be 135 Ohms resistance - a faulty one will be open-circuit (infinite resistance).

If you don't want to do this, then you need to read the stored Fault Code when it fails to determine whether it is the front or the rear which is failing.
Remove that sensor to the workbench and see if you can find the problem by flexing the cable along its length while measuring the resistance and looking for it going open-circuit due to a wiring fracture.
Other than that, purchase a new/used sensor and see if the fault clears.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: ABS Problems After Changing Brake Hoses

Postby pats.piercing » Mon Nov 27, 2017 12:17 pm

Hi,

Have just checked again as regards the self test procedure and have found the following:
Ignition on- Both flash together
Starter motor engaged - Flash Alternately

This indicates low battery voltage on start up. When I brought the bike it had been standing for at least 2 years but came with a new? battery. The guy I brought it from could not figure out how to fit the battery. I fitted the battery and also fitted my cable for my optimate at the same time. Over the months that I have been working on the bike (and waiting for parts) the battery seemed ok so I removed the optimate cable and fitted it to my wife's bike. This was during the period when I was waiting for the brake hoses. I have now refitted the optimate cable and will keep the bike on charge when not in use.

Hopefully this will overcome my problem.

Thanks everybody for all your help on this subject. Now just the clutch switch and neutral light problems to fix.

Mick

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george baker
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Re: ABS Problems After Changing Brake Hoses

Postby george baker » Mon Nov 27, 2017 12:57 pm

Hi
what bike?
George
Member 21, R100R, K75 and a Hyosung 250 FOR SALE

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Re: ABS Problems After Changing Brake Hoses

Postby Galactic Greyhound » Mon Nov 27, 2017 1:06 pm

Hi Mick,

If your ABS lights change to flashing Alternately when the Starter Motor is operated, then this could indicate a Battery or a Starter Motor problem.

FIRST - clean the Battery terminals and their leads to bright metal and apply a thin smear of Vaseline to all metal surfaces before reconnecting.
See if that clears the problem.

You can quickly prove it is a Battery problem by jumping a car Battery across the bike Battery terminals (don't run the car engine).

If the bike then starts without the ABS failing, then the bike Battery is suspect - it is either 'done' or it is not fully charged.
If the problem is still the same when using the car battery, then the Starter Motor is suspect.

If the bike Battery is suspect, put the bike Battery on charge for 24 hours and see if there is any improvement in starting without the ABS failure.
If there is not, and the ABS keeps failing when the Starter Motor is operated, then the bike battery is likely done.

I am not a fan of keeping a battery on permanent float charge believing that this is bad for the battery lifespan.
It is better to put the battery on charge for 24 hours once every 2 weeks or even 4 weeks.

The above assumes that the battery is not powering any accessories such as an alarm whereby you may not have much option but to float charge the battery if the bike is not being used for a long period.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: ABS Problems After Changing Brake Hoses

Postby pats.piercing » Mon Nov 27, 2017 3:48 pm

With the bike connected to the optimate and the starter operated the voltage drops to between 9 and 10 volts. I have got a power pack that I use to start my 7.5 litre motorhome engine but it is on loan to a friend at the moment. When I get that back I will try it with that connected.

I need to keep to battery on float charge as it sits in the garage for the whole of the winter with nobody around to run it occasionally.

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Re: ABS Problems After Changing Brake Hoses

Postby Galactic Greyhound » Mon Nov 27, 2017 5:24 pm

Hi Mick,

It is not advisable to operate the Starter Motor with a charger still connected to the Battery.

There is a risk of damage to the charger as the Starter Motor initially puts almost a short circuit across the battery before it gets up to speed and the starting current reduced.

Always check the Battery voltage without the charger connected which is more meaningful.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" - It works!

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Re: ABS Problems After Changing Brake Hoses

Postby pats.piercing » Mon Nov 27, 2017 9:12 pm

ok thanks

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Re: ABS Problems After Changing Brake Hoses

Postby pats.piercing » Tue Jul 10, 2018 4:40 pm

I have finally got the problem sorted. In desperation I changed the battery (again) and that sorted it out. The voltage was dropping too much with the starter motor engaged.
I have now sold the bike before something else goes wrong.


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