1995 R1100RS new purchase. Brake ABS bleeding question.

[P1k1968]

Just bought a lovely 95 R1100RS off of the original owner.  Non functioning front brakes, scored cylinder.

I replaced the brake cylinder and am bleeding the brakes.  The previous stressed a couple of different times NOT to mess with the ABS bleeders.  I have been making progress bleeding conventionally thru the caliper bleeders.  I am prepared to carry on this way, if it will ultimately work.

 

The ABS is flashing alternately, and as far as I can figure, this maybe related to battery voltage, or a system error.  Not sure how to diagnose the problem.

 

I rode it for a half hour before the front brake became too soft to be safe, and refilled/re-bled the system.  The brake feel is much better, but there is still some air in there, as constant pressure will eventually bring the lever to the bar.

 

So....

Should I keep at it with the conventional bleed?

Should I reverse bleed it with some kind of large syringe?

Why would the previous owner be so adamant not to touch the abs bleeders, what's the danger?

How to get more information on the abs fault?

What's the point of the ABS switch on the left side of the fairing?

 

Thanks,

Andy

 

[dirtrider]

3 hours ago, P1k1968 said:

Just bought a lovely 95 R1100RS off of the original owner.  Non functioning front brakes, scored cylinder.

I replaced the brake cylinder and am bleeding the brakes.  The previous stressed a couple of different times NOT to mess with the ABS bleeders.  I have been making progress bleeding conventionally thru the caliper bleeders.  I am prepared to carry on this way, if it will ultimately work.

 

The ABS is flashing alternately, and as far as I can figure, this maybe related to battery voltage, or a system error.  Not sure how to diagnose the problem.

 

I rode it for a half hour before the front brake became too soft to be safe, and refilled/re-bled the system.  The brake feel is much better, but there is still some air in there, as constant pressure will eventually bring the lever to the bar.

 

So....

Should I keep at it with the conventional bleed?

Should I reverse bleed it with some kind of large syringe?

Why would the previous owner be so adamant not to touch the abs bleeders, what's the danger?

How to get more information on the abs fault?

What's the point of the ABS switch on the left side of the fairing?

 

Thanks,

Andy

 

Afternoon Andy

 

You probably need to start by bench bleeding the front master cylinder. That most likely has a lot of air trapped in it so bleeding that out through the bottom is very/very difficult. 

 

To do that, fill the front master cylinder reservoir then slowly work the hand lever only about 1" or so (just enough to get air to back up through the take-up port hole in the bottom of the reservoir (do not pull the lever full stroke).

 

Once you get to the point that no air comes up from the bottom of the reservoir at lever release then move on to bleed at the calipers using a full stroke & catch container.  Put a hose on the front caliper bleeder then terminate that hose in the catch container UNDER  the fluid in the catch container (hose end must be below fluid level in the catch container). The hose ending below fluid level acts like check valve allowing full lever pumping with no need to close the bleed screw. 

 

Then with the caliper bleeder open start pumping the hand lever (get a lot of continuous fluid flow), caution: do not run the reservoir out of fluid.

 

That should give you a decent lever feel but you will probably still have some air trapped in the ABS module. You will probably have to bleed at the ABS module bleeders to get all the air out. 

 

As for the flashing ABS lights. EXACTLY when do they go from flashing together to flashing alternately? At key ON, or during engine cranking, or at first brake usage? This hopefully will tell where to start looking for the problem.

 

 

 

  

 

 

[P1k1968]

As soon as the ignition key is turned on, the abs lights are alternately flashing.

[dirtrider]

1 minute ago, P1k1968 said:

As soon as the ignition key is turned on, the abs lights are alternately flashing.

Afternoon Andy

 

Then first bleed the system.

 

Then try an ABS reset__   

 

 

First, find the diagnostic connector (located under the seat). 

 

Then, insert one end of a wire into the middle socket of that connector. 

 

Then, ground the other end of that wire to a (clean) metal part of frame or good ground area (make sure it stays grounded). 

 

Next, turn on ignition switch. You should now see the warning lights flash alternately.  

 

Next, hold ABS button down for a long 8 seconds (possibly slightly longer). The bottom ABS light should stay on, and the top light should be off. 

 

Then, release the ABS button. If you have successfully reset the ABS system then both ABS lights will come on. If you have failed to hold button for 8 seconds, or your ground is not good, then the top ABS light will probably stay off.

 

Remove grounding wire.

 

If that doesn't help then we will have to dig in farther (possibly stuck ABS pump pistons) or wiring issue or ????
 

[Michaelr11]

6 hours ago, P1k1968 said:

The ABS is flashing alternately, and as far as I can figure, this maybe related to battery voltage, or a system error.  Not sure how to diagnose the problem.

DR is giving you good advice. On your 1100RS, lovely bike btw, the ABS2 system should flash both lights together when the key is first turned on. If the lights flash alternately at key on, you have a captured fault code. You have to perform the reset to clear that fault code.  Low battery voltage when you press the start button is the only fault code that clears when you turn off the key. It appears right after you start the bike and before you try to roll away. You can try one other thing. After you bleed enough to get a reasonably good lever feel, pump it to get firm pressure and then put enough rubber bands on the lever and grip to hold the front lever firmly. Leave it like that overnight.

 

Where are you located?

 

[P1k1968]

I am near Lancaster PA.

tried the reset, no difference.  Well the lights did flash together while riding right after the reset, they did not go out as I built up speed.  But started flashing alternately as soon as restarted it.  I did a short test ride, lost about half of the reservoir. No obvious leaks no time to re bleed tonight. As soon as power on they are flashing alternately, and stay that way the whole time.

 

while doing the reset they always flash intermittently, never get the solid lower light on.

[dirtrider]

11 hours ago, P1k1968 said:

I am near Lancaster PA.

tried the reset, no difference.  Well the lights did flash together while riding right after the reset, they did not go out as I built up speed.  But started flashing alternately as soon as restarted it.  I did a short test ride, lost about half of the reservoir. No obvious leaks no time to re bleed tonight. As soon as power on they are flashing alternately, and stay that way the whole time.

 

while doing the reset they always flash intermittently, never get the solid lower light on.

Morning Andy

 

If the lights start flashing alternately at key on that is usually a faulty ABS module, if they only start flashing alternately at engine cranking then that is usually either a low cranking voltage issue or an internal ABS module issue. In your case you did a hot engine restart  & still got the alternately flashing lights so in most cases that doesn't point to a low cranking voltage issue but it isn't totally eliminated either.  

 

Do another reset, then ride it, then JUST turn the key on, do not start engine__ What are the lights doing???? 

 

If that motorcycle was stored or sat for long while you could easily have a stuck piston or pistons inside the ABS module. That could also explain the loss of 1/2 reservoir of fluid as those cylinders can store a lot of fluid if a piston moves down. (your ABS-2  system uses a rotating shaft, clutches & movable displacement pistons to provide ABS function). It's an old (rather crude) SLOW reacting ABS system. 

 

Personally I would just remove the ABS system,  that gives more predictable braking, a LOT less future issues,  easier to bleed, less weight up high where it matters. 

 

I don't know what the laws are in your area as far as safety inspections go but the 1100RS was available without ABS so if it is all removed & re-plumbed properly then they probably wouldn't even know that it was supposed to have ABS. 

 

Removing the ABS-2 system on the BMW 1100 is very easy as it only takes a short piece of brake pipe for the rear, or just buying a longer rear brake hose (if you have an aftermarket rear brake hose it might already be long enough as is).  The front can usually just use the stock hoses by flipping the hose junction block.

 

If you are above average in mechanical ability you can also remove & disassemble the ABS  module then clean it out & sometimes restore function but in (my opinion) it isn't worth the bother as even at it's best that ABS-2 system is slow, unpredictable, tends to release the front brake when you don't want it to, & doesn't work worth a hoot on very slippery road surfaces. 

 

You can also just mask the dash lights & ride it without active ABS but that leaves the weight, complexity, & visible remains (if your state has safety inspections). 

 

If you have access to an old analog 12v DC  voltmeter you can try to grab the ABS faults but that is kind of iffy & the fault code list is short as it only checks for a few main faults. Those COULD be the issue or issues, or could just be set because of a non-related issue causing one of those to set. 

 

In your case it doesn't even seem to be working long enough, or correct enough, to set a useful or meaningful fault. 

 

 

My somewhat educated guess from past experiences is that you probably have a stuck piston or pistons inside the ABS module. 

 

You can call ModuleMasters as they can probably repair it but at a cost that probably isn't worth the bother. 

  

 

 

[P1k1968]

I think you are probably right regarding a mechanical issue with the ABS unit.  

The alternating lights are on as soon as power is on, they have only briefly flashed together after a reset but they did not go out at all even 

when I was up to 40mph.  Once I turned off the engine and restarted it, they were back to alternate flashing.

 

I used about a half reservoir of fluid while doing a short 10 mile ride last night.  I will look into removing the system.

 

Andy

[dirtrider]

5 minutes ago, P1k1968 said:

I think you are probably right regarding a mechanical issue with the ABS unit.  

The alternating lights are on as soon as power is on, they have only briefly flashed together after a reset but they did not go out at all even 

when I was up to 40mph.  Once I turned off the engine and restarted it, they were back to alternate flashing.

 

I used about a half reservoir of fluid while doing a short 10 mile ride last night.  I will look into removing the system.

 

Andy

Morning Andy

 

You need to pay attention to EXACTLY when the lights start flashing alternately.

 

If at the instant of initial key-ON?

 

Or at engine cranking? 

 

It makes a difference.

 

The flashing together doesn't tell you much, it's instant they go from flashing together to flashing alternately that you need to define. 

 

 

[P1k1968]

As soon as I turn the key, the ABS lights flash alternately.

 

When I do the reset procedure, they never vary from flashing alternately.  No solid lower light when restting.

 

Andy

[dirtrider]

26 minutes ago, P1k1968 said:

As soon as I turn the key, the ABS lights flash alternately.

 

When I do the reset procedure, they never vary from flashing alternately.  No solid lower light when restting.

 

Andy

Morning Andy

 

That usually points to one of 3 things. 

 

It needs to be reset (you did that & it didn't help) 

 

Or a failed ABS module (typically a stuck piston or pistons). If it sat a long time then possibly also etched pistons & cylinder bores). 

 

Or possibly a failed ABS motor relay (under a sliding cover on the side of the ABS module). 

 

Maybe a 4th possibility, no 12v B+ on the red wire going to that ABS motor power relay. That red wire comes directly from the battery B+ post (no fuse). 

[P1k1968]

I guess the next steps are to pull the tank and look at the relay and the battery connection then.  I don’t hear any relays when I turn the key on.

[dirtrider]

13 minutes ago, P1k1968 said:

I guess the next steps are to pull the tank and look at the relay and the battery connection then.  I don’t hear any relays when I turn the key on.

Morning Andy

 

You won't hear that ABS motor relay as it only comes on to run the ABS shaft motor. 

 

You can hear the ABS relay in the fuse box click but that just lights and/or flashes one of the ABS dash lights (has no effect on the actual ABS operation).

 

  

 

[P1k1968]

Is the relay part of the self check that could be causing the alternating flashing lights?

If it is not, then I guess its not the immediate cause of the problem

[dirtrider]

2 minutes ago, P1k1968 said:

Is the relay part of the self check that could be causing the alternating flashing lights?

If it is not, then I guess its not the immediate cause of the problem

Morning Andy

 

Yes & no, it is part of the ride away test but I don't think it is part of the key-ON electrical test. 

 

If your dash  lights are flashing alternately at initial key-ON then that is well before the ride-away motor test. 

 

But that relay is controlled by the ABS electronics so it might be looking for the relay pull-in coil low side B+ at key ON. (I don't think it makes a difference but I can't say for certain without testing a known good system) 

 

I have seen both a failed ABS motor power relay & the motor itself trigger a fault after ride-away but I can't remember seeing it set a key-ON alternating light flash (but that doesn't mean that it doesn't, it just means that I can't remember seeing it).  

[P1k1968]

Making progress, while bleeding the brakes (again), I heard a faint "whistle", found a compromised brake line.  I ordered the Spiegler Performance SS brake kit.

While having the fuel tank lifted out of the way, I checked out the battery voltage and connections.  All seemed good.

 

So, ABS no closer.  But I should at least have a functioning non abs system soon.

 

Cheers,

Andy

[P1k1968]

Installed the Spiegler hoses, now i have fluid coming out the right side of the abs unit, about half way up.

 

Going to look at bypass kits or a replacement used unit.

 

Andy

[dirtrider]

20 minutes ago, P1k1968 said:

Installed the Spiegler hoses, now i have fluid coming out the right side of the abs unit, about half way up.

 

Going to look at bypass kits or a replacement used unit.

 

Andy

Afternoon  Andy

 

It almost sounds like someone had that ABS module apart & didn't get it back together & sealing properly. 

 

You don't really need a kit, front parts will work as-is with a flip/minor grind of front hose to line junction block. Rear will just need a new short pipe between master cylinder & hose, or just a slightly longer hose (direct from master cylinder to caliper).  

 

Then just remove the ABS light relay from the fuse box.

[P1k1968]

I found a decent looking used unit on ebay.  For the $100 i might get lucky and get a functioning unit, or at the very least one that is not leaking.