Parking Brake has Intermittent engagement - any ideas?

[nazdackster]

2014 Sypder RT SE6. Parking brake indicates on when commanded, and I can feel foot pedal change. Brake MAY or MAY NOT be on after that. If it does engage, it is fine, and tight. Or it may roll. If I let it roll a bit then engage, I can feel it grab every time (as if ABS is employed to sense movement and send multiple commands...?). If I don't roll it, I can't tell whether it will turn out to be on or off, but sometimes I can roll it. Brake does alarm if engaged and I attempt to drive off in gear, and depending on whether it is actually engaged or not, it will resist movement, or not. It goes off and indicates off OK. I can hear and feel the movement happening, but I don't check that every time. I feel a change in pedal if I look for it.

I don't know whether it had been doing this before (it was my Wife's dad's machine), but rear pads were just changed by me, and parking brake cable was in-spec after the change (1mm play at back end, no adjustment required). I did actuate fluid brakes several times to tighten those up against the disk before turning the Spyder on. I also actuated the parking brake several times to check the play. It all looked good.


On an unrelated (but possibly related) note, the analog fuel and temp gauges are also sometimes intermittent, though I don't think that correlates all the time. The brake just worked with gauges not working. I removed the gauge cables, one felt not as snug as I would like, I adjusted the female terminals a bit and got a tighter fit. Grounds (presumably for lights) felt fine, good and tight. No change, works intermittently too. One post said it was the instrument cluster that was bad, and drives the analog gauges.

Mainly interested in brakes for this thread (may submit other problem in a different thread). Thanks!

 

[BertRemington]

Being thicker, new brake pads are going to change the distance the parking brake drum rotates. You will probably have to adjust the microswitch position because the cable stretched from new.

The cluster drives the coolant gauge (which gets temperature from the ECM via CANbus) but not the fuel gauge which is in parallel with the cluster. The gauge connectors are kinda cheap so try cleaning and tightening then.

 

[nazdackster]

I read the manual and it recommends adjusting the cable, which I did. It is very unclear though about the amounts, other than start with 6mm (from what, and how do you know if you need to?), so here is what I found:
1) Now I definitely don't understand what the 1mm spec is for dimension A. I figured I wanted about 1mm clearance of the cable, which means it is neutral and loose when brake is off, like a throttle cable would be.
2) The motor engages until a microswitch clicks, then releases a bit. This pulls the arm maybe 10mm and releases 3mm.
3) I pushed on the arm and it had probably 7 to 8mm before it felt engaged fairly tight. Brakes stopped bike.
4) I loosened both the cable nut and adjuster, and moved it about 3mm, and tightened.
5) At the arm, now it feels like it has 4 mm or so before it starts building force, so I think it has clearance inside the mechanism when off, but it won't have any cable clearance when off now. I could go a little more too.
6) The arm will be tighter now. I suspect that due to runout or some other manufacturing tolerance, I was on the edge of engaging or not at the cable position it was at. It feels like it should be OK now. The motor did act the same while I had an assistant activate and release MANY times, so I think it's OK.
7) The release / motor reversal amount at the arm stays the same no matter the adjustment of the adjusters, the motor just backs off a bit and stops (I presume this is normal, it goes to a rest position or has a locking clutch when powered off so it doesn't need power at this position, (guess). Maybe what I'm seeing is a clutch or engagement backlash to the locked position.
8) There are videos of the Brembo brakes where more severe adjustments are made by rotating the mechanism inside the hub after removing the 16mm bolt at the end of the axle. You adjust with an allen wrench I think... I didn't do that. But I did turn it all the way back in, minus a little bit, to accommodate the new pads when I did the tire. I was under the impression that by doing that, it must self adjust, otherwise why did I need to rotate it so many turns to replace the worn pads?
9) All the lights, etc still work the same, no adjustments needed.

Rode it. The parking brake seems a lot stronger. If it still ends up being intermittent, I will update later, otherwise, that's how you can adjust per the service manual.

 

[Kevin]

The parking brake on my 2010 RT-S was intermittent in operation until it failed to engage competetely when attempting to apply. The parking brake lamp would flash all the time. Turned out that my rear pads were worn down enough that the parking brake sensor couldn't confirm the brake was on and disabled it.

 

[nazdackster]

So far nothing has worked and I'm out of adjustment. Better than it was but still intermittent. I ran across this thread which describes a bad motor (bad brake inside motor? Makes sense). https://www.spyderlovers.com/forums...2014-RTL-SE6-Parking-Brake-quot-relaxing-quot So if anyone has the TSB for that, please let me know. What I'm noticing about backing off seems to be a motor problem. Any insights appreciated.