ABS Not Working/Working

[radiofun1]

I have a 1999 r1100s. As you know, the ABS lights flash back and forth upon startup and then go out once you pull away. Occasionally, the lights on my bike continue to flash after I start off. If I cycle the key off and then on while riding the ABS light go out, so assume (perhaps falsely) that the ABS is then functional. Any idea what's going on?

 

[m_stock10506]

ABS2? Yes, if they go out after you cycle the ignition off and then back on, then your ABS is functioning. What you described is classic low voltage error on startup. How’s your battery? How old?

 

[radiofun1]

Low voltage could definitely be the problem. I bought the bike a year ago and am not sure how old the battery is. I don't have a battery tester, but the trickle charger takes a couple hours to bring the voltage back up, so I suspect the battery is on its way out. Time to change it.

 

[179212]

Low voltage

Starter going bad and drawing excess current can cause same problem

 

[happy wanderer]

To find out what is going on the best thing is to measure the voltage at the battery while cranking. If the voltage gets down around 10 VDC the ABS will generate a fault. In this case, nothing wrong with the ABS. It is doing what it is supposed to do.

In order to find out if it's the battery or starter dragging down the voltage, put a load tester on the battery and check the reading. If it's bad then your battery is at or near end of life.

The other possibilities are either a bad connection from the battery to the starter or the starter is dragging because it needs servicing or replacement depending on what is wrong with it.

Replacing (bleeding) all the fluid in your brake system including the ABS needs to be done annually to keep the ABS pump and it's innards in good nick. Bleeding only the brakes is not enough. Need to do the ABS unit as well. Two bleed screws for the unit in that bike IIRC.

 

[radiofun1]

To find out what is going on the best thing is to measure the voltage at the battery while cranking. If the voltage gets down around 10 VDC the ABS will generate a fault. In this case, nothing wrong with the ABS. It is doing what it is supposed to do.

In order to find out if it's the battery or starter dragging down the voltage, put a load tester on the battery and check the reading. If it's bad then your battery is at or near end of life.

The other possibilities are either a bad connection from the battery to the starter or the starter is dragging because it needs servicing or replacement depending on what is wrong with it.

Replacing (bleeding) all the fluid in your brake system including the ABS needs to be done annually to keep the ABS pump and it's innards in good nick. Bleeding only the brakes is not enough. Need to do the ABS unit as well. Two bleed screws for the unit in that bike IIRC.

Thanks - I will do a draw down test on the battery, which I suspect is the problem. Recently bleed the brake circuits, including the ABS modulator, together with a full service as this bike was new to me last fall and I have no service records.

 

[happy wanderer]

Thanks - I will do a draw down test on the battery, which I suspect is the problem. Recently bleed the brake circuits, including the ABS modulator, together with a full service as this bike was new to me last fall and I have no service records.

Awesome. The other thing I forgot to mention is the brake lines. If they are the original black rubber lines they need to be replaced given the age of the bike. They go bad from the inside out. Sometimes they give themselves away with bulges or disformations in the lines that are visible from the outside the but more common failure is rot on the inside which gets into the ABS modulator valves and also, even more dangerous, is when some rotten rubber bits get caught up in the return oriface in the calipers. In this scenario you grab the brakes, they come on and now will not release! Extremely dangerous.

There are numerous posts here and some great ones from GSAddict showing what the insides of some of the many lines he has replaced over the years look like inside when they look just fine on the outside.

So if your new to you bikes still has the OEM lines order some Spiegler replacements and change them out. Cutting them open after you do that will confirm it's the right thing to do.

 

[radiofun1]

Thanks Happy. Yes, I replaced the brake lines with Spieglers when I did the full service last fall. Made a big difference in the braking power.

 

[2slowwheels]

Anecdotal: one of my riding buddies has a '96 RT, 115,000 miles, original brake lines and the brakes were flushed once on each end account leaking master cylinders, ABS still works, some people are lucky.

 

[dieselyoda]

Anecdotal: one of my riding buddies has a '96 RT, 115,000 miles, original brake lines and the brakes were flushed once on each end account leaking master cylinders, ABS still works, some people are lucky.

Yes, our OE brake hoses, as repeated here on the Oilhead forum are problematic but you don't see the same Mantra about brake lines on the K-Bike forums????

Maybe, K-Bike owners are more diligent to routine maintenance and therefore..................replacing brake hoses at the sign of any problem isn't really an issue?

Market routines on any type of machine would tell you that 5 years from a battery is pretty damn good, brake hoses should never need to be changed unless of weather checking or damage and good oil, regardless of specification is better than not replacing the best oil routinely.

 

[gsaddict]

Yes, our OE brake hoses, as repeated here on the Oilhead forum are problematic but you don't see the same Mantra about brake lines on the K-Bike forums????

Maybe, K-Bike owners are more diligent to routine maintenance and therefore..................replacing brake hoses at the sign of any problem isn't really an issue?

Market routines on any type of machine would tell you that 5 years from a battery is pretty damn good, brake hoses should never need to be changed unless of weather checking or damage and good oil, regardless of specification is better than not replacing the best oil routinely.

K bikes of that vintage have the same issues. I have replaced the rubber lines on those as well.
And while on the subject, the OE F's fail as well.