Last Friday my VSA, VSA activation (!) and e-brake light stayed on while driving home. I stopped the car to make sure everything was alright. Brake fluid was more than halfway between low and high but closer to high which seemed fine. I drove the car back home and did my research in the helms manual and s2ki.

Based on the manual and my research, the evidence pointed to low fluid, worn pads causing low fluid, or a bad float sensor in the brake master cylinder reservoir. To eliminate the possibility of low fluid, I added brake fluid to almost the "high" mark on the brake master cylinder reservior; all lights were still on.

I opened the reservoir to inspect the float switch and found that the float was not floating. I could reach in with a small screwdriver to lift the float up and it seemed to stay (which made all three warning lights go off. At this point I thought I had fixed the problem and left it alone.

The next day I went for a drive and for 20-30 miles I had no problem. On the way back home, the lights came on again. When I got home to inspect, the float had sank to the bottom again.

After doing some more research, it would appear that I need to replace the entire master cylinder. I am not satisfied with this, the master cylinder is fine, Is there any way I can just replace the float, or maybe the reservoir with float? It seems like a pricey repair for a stupid little sensor.

Thanks in advance.

TL;DR: brake fluid float sensor bad, need to replace entire master cylinder, any other way?

 

Mine did this for about 6 months on my 01'. I knew it was just the floater so it didn't bother me too much. It would come on and off at random, but if it were off I could get it to come back on almost every time if I cornered hard. After a brake fluid change, the light has stayed off. So long as it isn't anything aside from the floater, changing the entire master cylinder would be so wasteful. Try a fluid change to see if that changes it. I had mine done at a local garage, so I'm not sure if they do something differently from what would be done in a driveway.

 

Thanks for the reply. I think I will keep going to the next service point, I reset the float yesterday and it seems to be staying for now but that could change. What is annoying with the AP2, if the float sensor is tripped, the computer assumes the brake fluid is low and disables the VSA. I guess I can just unplug the sensor but I don't want to start half-a$$ing things on this car.

 

9/27 update (because I know you care)

I "reset" the float with a small screwdriver for the second time on Sunday afternoon. At this time it appears to be holding (for now). I do not see this as a permanent solution as the float can potentially dislodge during spirited driving. If the float disloges at that time, it will deactivate the VSA when you need it the most. I am surprised there is not a TSB for this as this could potentially cause a dangerous situation.

Has anyone else been able to repair the float mechanism without changing the master cylinder?

 

Omg I love this page more and more!

 

Honestly, aftermarket master cylinders run 100-150 and OE can be had for 200. Could be worse, right?