I have a 2014 CB1100 Deluxe in my collection that has been ridden very little. about 447 miles to be exact. I rode it a couple of weeks ago after cleaning it and servicing the oil and filter and everything seemed fine. Today, I rolled the bike off the centerstand and almost lost it as the front brake would not stop the bike at all. Front brake lever is quite firm, but absolutely no front brakes. Tried bleeding the front calipers but no fluid comes out and the lever remains firm even with the bleeder screws open. It's not the master cylinder, loosening the hose connection banjo allows fluid to pump out, so now I'm thinking that the ABS modulator has an internal failure like a stuck solenoid valve. The ABS warning light illuminates, does a self check, and goes out.
Anyone have an idea what's going on?
Did you wash it with a hose and water? It's possible a piston rusted slightly and is now locked in position. I haven't heard of this happening so quickly to a bike in storage though. I suggest that you do NOT apply excess pressure to the lever to try to unlock it though. Disconnect the hose from the caliper and use compressed air to try and free up the pistons.
You could be right about the ABS unit but I think I would be tempted to remove each caliper, leave them connected to the hydraulics, remove the pads and clean up the pistons with a toothbrush and soapy water and then see if you can push them back in a mm. Once you have confirmed the pistons move throw them back on and try again.
Well, it's not the calipers or master cylinder since fluid pumps out of the brake hose connection when loosened, and calipers are fine. The issue is that the ABS modulator is blocking fluid travel to the front hydraulic circuit as there is no fluid coming out of the bleeder screws. Forcing the lever and attempting to make the ABS pump run finally freed things up and I managed to get a whole liter of Castrol Dot 4 cycled through the system and bled. Brakes working fine now, but hesitant to ride in traffic until I am 100% sure this won't happen again.
I, for one, can appreciate the user name. Well done!
Yeah, that's a tough one. You certainly need some level of trust with the brakes. I'll check my service manual to see if the ABS module can be serviced/tested.
Roger i was under the impression that the passage from the front master to the calipers is always open unless the abs is operating due to altering wheel speed, just wondering if the front brake is now working as expected with the ignition switched off?
As far as i understand the brake switch on the lever is also part of the abs cycle in combo with the wheel sensors, maybe an abs valve was left in the wrong state ( sticking) when the engine was last switched off........
How long ago has the fluid been changed and what did the old fluid look like when replaced?
There is likely still some old fluid inside the abs module, unless it actuates multiple times it just sits there and gets old.
If it was me i would find a grassy area and operate the abs system ( handle vibrates ) multiple times until you feel it is reliable, interesting and if my memory serves me correctly ( rare these days ) there was another member with a similar brake malfunction, he or someone might chime in here, we could not understand why it happened but your case shows that it did, very interesting.
Just got back from the Triumph dealership where a pretty green Steve McQueen edition Scrambler 1200 was waiting for me to look at, and luckily the brakes were totally fine on the way there and back. I'm going with my initial assessment that the ABS front brake channel solenoid was stuck, and running a fresh liter of DOT 4 through it got things freed up. Working the lever with the ignition on and shorting the brake switch connectors seemed to do the trick.
Fluid was a dark amber color and didn't look like Italian salad dressing so I am sure just running some new DOT 4 through it is all it took to fix it. A new ABS modulator is $1,500 and buried under the battery box, in front of the rear fender and it sits in a support just over the swingarm so I'm really happy it did not have to come out.
There is likely still some old fluid inside the abs module, unless it actuates multiple times it just sits there and gets old.
Hi Max. Excellent advice, as usual. If old fluid just sits in the ABS module unless it is activated, what is the best way to change the brake fluid to make sure all the old fluid is completely removed? I would like to ask a question about the CB1100 ABS system because I know how wise you are, and you always provide excellent explanations: If the ABS senses the front wheel locking and activates, is the ABS function automatically activated for the rear wheel. or does the ABS system independently sense and activate each wheel? Maybe one of your technical explanations? Thank you Max.
The problem was likely related to the long term storage of the bike at my warehouse, inactive for about two years. Luckily, manipulation of the brake levers and vacuum bleeding the system restored function.
Bleeding the brakes by activating the ABS pump and energizing the solenoids is nothing new to me as an auto technician, and I have diagnostic platforms and software to perform the power bleed on modern car and truck ABS systems. Unfortunately, it's not as easy on most motorcycles as there really isn't a widespread standardized communication protocol and the data connectors and cables are proprietary.
My Triumph Bonneville T120 is an exception. It has a multi pin DLC which I can plug an OBD2 Bluetooth adapter into and pair it with my android phone running a TuneEcu app. This allows me to retrieve and clear fault codes, reset the maintenance indicator "wrench" symbol on the clocks, synchronize the throttle bodies, and perform a power bleed of the ABS system.
I wish this was available for my CB1100. Purchasing the factory service tools, software and diagnostic platform is cost prohibitive to say the least.
@ Roger
I read your post with quite some feeling of "unbelievable". Bad fluid or not, as long as there is enough fluid in a hydraulic system, one of the four disk pads in front should have moved and this should have given you some brake action, enough to bring her to a stop after rolling of the center stand. But you said "absolutely no front brakes". Next you said, bleeding didn't show any fluid (on both sides ?).
Even so you fixed it (glad for you !), this is still worth better understanding. For you, to make sure it doesn't come back, for us, to avoid a similar situation.
Do you think you might be able to carefully describe once again what you did and in which sequence ?