Hello, I have watched this forum for a long time and just signed an account in. I’ve been a fan of 80 and100 series for many years and I’m sorry I’m late to meet you!
I kinda need real help with this problem. Some time in the last week, my entire brake system went failured. Loudly audible beep sound came from my cluster and I have the checking lights shown as ABS, VSC Trac, Trac Off and Brake lights like a Christmas Tree. Nothing felt weird right before all issues kicked in, no any signs. Then I felt my brake pedal went very soft after this thing started. I could easily push 70% into the pedal and after that it takes my whole leg to brake it. Whole system stopped working including the electric motor. I was luckily in a parking lot not in the traffic. No leaks in brake lines and 4 calipers, and the brake fluid reservoir are full. I used my own OBD reader it showed no code, I went to Autozone and used their Bosch one and it showed no code.
All things came up on the Internet as it’s a electric motor fail. But based on my knowledge, if the electric motor failed, I am supposed to have no brake assistance with a super stiff pedal feeling, while mine is actually really soft, which does not actually explain the problem. It doesn’t feel like leaking, the 1st time I push on the pedal it would go 70% in and if I release it and push back immediately it will go 40% in and still have some brake.
I bought a Master Cylinder Rebuild Kit, and rebuilt the MC thanks for the thread of Skidoo:
Master Cylinder Rebuild - DIY
I did the rebuilt in the past weekend. When I removed all the 4 brake lines connected to the cylinder when I started tearing parts down, I found the 2 ports directing to rear brake did not have much oil dropped out from the port, I was expecting a whole mess, but it didn’t happen.
Below is a picture of the 2 ports that I talked about, I circled them:
I mentioned that but continued the rebuild, well, they couldn’t be worse with the rebuild.
After I finished the rebuilt, I put the part back on, in need of bleeding the master cylinder before wheels because there’s whole lot of air in the whole system. Do not connect the brake lines right after assembling, keep pressing the brake inside, and put fingers on the hole and feel the pressure if able to, that will push the extra air in the master cylinder, and whenever you see pressured brake fluid coming from a port, then connect that brake line which has fluid came out. My 2 ports facing front did a good job, after several press, brake fluid came out of the ports and could shoot several centimeters away, I connected these ports. Then comes the problem, my 2 ports circled in the picture above just does NOT bleed anything out. I can feel it sucking air when the brake pedal is released and can feel some air going out with almost ignorable bubble (but I heard them). No fluid came out.
I did not continue to do wheel bleeding, because I can’t understand this. Now what I have is a similar brake pedal feel as before the rebuild, which is soft. I am going to bleed the 4 wheel calipers but I don’t think I could bleed anything out if there is even no pressure going out of the MC to the rear.
The system still does not work, the motor does not work, which is reasonable because what I’ve heard is if there is any kind of low pressure occuring in the system, the system will set itself up in the protection/safe mode, with the alert turned on and the motor resting, as I haven’t bled them, they shall not be working. I tried to clear the code by ‘make a bridge connection in the analysis port inside the right fender, connecting Tc and E1, turn on the ignition and press the brake pedal for 8 times in 5 seconds’(FSM), and that did not clear the code.
As everything’s going and I want to figure this out, either in the wish of not spending several K in purchasing the whole unit and want to know how could that happen. If anyone have seen this kind of problem please give me some advice. I’ll definitely take everyone’s advice and let u know how I fixed this at the end!
Thank you!
I kinda need real help with this problem. Some time in the last week, my entire brake system went failured. Loudly audible beep sound came from my cluster and I have the checking lights shown as ABS, VSC Trac, Trac Off and Brake lights like a Christmas Tree. Nothing felt weird right before all issues kicked in, no any signs. Then I felt my brake pedal went very soft after this thing started. I could easily push 70% into the pedal and after that it takes my whole leg to brake it. Whole system stopped working including the electric motor. I was luckily in a parking lot not in the traffic. No leaks in brake lines and 4 calipers, and the brake fluid reservoir are full. I used my own OBD reader it showed no code, I went to Autozone and used their Bosch one and it showed no code.
All things came up on the Internet as it’s a electric motor fail. But based on my knowledge, if the electric motor failed, I am supposed to have no brake assistance with a super stiff pedal feeling, while mine is actually really soft, which does not actually explain the problem. It doesn’t feel like leaking, the 1st time I push on the pedal it would go 70% in and if I release it and push back immediately it will go 40% in and still have some brake.
I bought a Master Cylinder Rebuild Kit, and rebuilt the MC thanks for the thread of Skidoo:
Master Cylinder Rebuild - DIY
I did the rebuilt in the past weekend. When I removed all the 4 brake lines connected to the cylinder when I started tearing parts down, I found the 2 ports directing to rear brake did not have much oil dropped out from the port, I was expecting a whole mess, but it didn’t happen.
Below is a picture of the 2 ports that I talked about, I circled them:
I mentioned that but continued the rebuild, well, they couldn’t be worse with the rebuild.
After I finished the rebuilt, I put the part back on, in need of bleeding the master cylinder before wheels because there’s whole lot of air in the whole system. Do not connect the brake lines right after assembling, keep pressing the brake inside, and put fingers on the hole and feel the pressure if able to, that will push the extra air in the master cylinder, and whenever you see pressured brake fluid coming from a port, then connect that brake line which has fluid came out. My 2 ports facing front did a good job, after several press, brake fluid came out of the ports and could shoot several centimeters away, I connected these ports. Then comes the problem, my 2 ports circled in the picture above just does NOT bleed anything out. I can feel it sucking air when the brake pedal is released and can feel some air going out with almost ignorable bubble (but I heard them). No fluid came out.
I did not continue to do wheel bleeding, because I can’t understand this. Now what I have is a similar brake pedal feel as before the rebuild, which is soft. I am going to bleed the 4 wheel calipers but I don’t think I could bleed anything out if there is even no pressure going out of the MC to the rear.
The system still does not work, the motor does not work, which is reasonable because what I’ve heard is if there is any kind of low pressure occuring in the system, the system will set itself up in the protection/safe mode, with the alert turned on and the motor resting, as I haven’t bled them, they shall not be working. I tried to clear the code by ‘make a bridge connection in the analysis port inside the right fender, connecting Tc and E1, turn on the ignition and press the brake pedal for 8 times in 5 seconds’(FSM), and that did not clear the code.
As everything’s going and I want to figure this out, either in the wish of not spending several K in purchasing the whole unit and want to know how could that happen. If anyone have seen this kind of problem please give me some advice. I’ll definitely take everyone’s advice and let u know how I fixed this at the end!
Thank you!
