Volvo A25D Brake Over Stroke Warning

[Pocho86]

hey

Volvo A25D Serial 15040

So I got some warning lights that came on. Apparently its a Stop light and another light and in manual indicated there is a Brake Over Stroke detected (Leak, Blown Line, Worn Pads, Etc)

I was able to narrow it down to the front LH brake master/air chamber thats stroking the rod out almost all the way.

How Do I Turn This Light Off, is there a reset procedure? Do I need to use the laptop?

I unplugged that sensor on that air chamber and warning still stayed on. I jumped the two wires and same thing. So if its unplugged and jumped and no change, maybe a reset procedure of some sort needs to be done?? Unless I need to ground one of the wires?

 

[sfrs4]

That is an open circuit, to turn to the light off the wires shouldn't be joined. I just spoke with one of our fitters he said "did they push the rod back down that is next to the sensor, it won't spring back it needs to be manually reset" and check the sensor still springs back, these can get stuck

 

[Nige]

Here's how it works on a Cat brake cylinder, but the theory is the same.
The Pin (3) is pushed in the direction of the arrow when the piston of the brake cylinder overstrokes. That activates switch (2). The two O-rings (9 & 14) hold the pin in place, either up or down it makes no difference. So the pin does not return on its own, you have to physically push it back.
Another thing, and I can't stress it strongly enough - DO NOT OPERATE THE MACHINE until the cause of the brake overstroke has been located and repaired. That alarm is telling you that you have reduced braking capacity, and potentially that you could have no braking capacity at all.