ABS Solenoid Valves
Thread Starter
Pro
Joined: Mar 2007
Posts: 595
Likes: 355
From: Mt Prospect IL
2025 C4 of the Year Finalist - Unmodified
ABS Solenoid Valves
Just wanted to post a success story for my '96. I have been fighting a dropping brake pedal. while it never went to the floor like a broken brake line, it "felt" like a bad master cylinder or air in the lines, ie: when approaching a stop the pedal would drop unusually low and yet you could be pumped up to normal. I am very guilty of not taking all the necessary preventative maintenance procedures (flushing Brake Fluid) with the car over the years so I started with the most obvious.
Day 1. Call the neighbor and let's bleed the brakes. I checked the moisture content of the fluid before bleeding and it was at 3% so new fluid it is. No change in the pedal. Order Master Cylinder.
Day 4. Let's replace the Master Cylinder. Neighbor busy, Bleed tomorrow. Let's have a beer
Day 5, Call the neighbor, Bleed system. Now the Brake Pressure light is illuminating when applying heavy pressure with engine running and goes out as soon as pedal is released. No Good there. Time for a beer and think on it.
Day 7, Reinstall original Master, Buy Pressure bleeder on Amazon. Might as well have a beer while I wait on Amazon.
Day 9, Pressure bleed the brakes, back to original problem. Grab a beer and back to the service manual.
Day 10. Hook up the Tech II and cycle the Rear Solenoids. Pedal is higher but still dropping slowly when coming to a stop. Park it and grab a beer.
Day 12. Hook up Tech II and cycle all solenoids, Pressure Hold and Pressure Reduction all 4 wheels. Brakes now work perfectly and pedal is up where it belongs with no dropping. I think it's time to celebrate with a Frosty Cold Beer!
Takeaway Lesson. 25 year old car, Cycle ABS solenoids once a year at the start of spring!
Cheers.
Day 1. Call the neighbor and let's bleed the brakes. I checked the moisture content of the fluid before bleeding and it was at 3% so new fluid it is. No change in the pedal. Order Master Cylinder.
Day 4. Let's replace the Master Cylinder. Neighbor busy, Bleed tomorrow. Let's have a beer
Day 5, Call the neighbor, Bleed system. Now the Brake Pressure light is illuminating when applying heavy pressure with engine running and goes out as soon as pedal is released. No Good there. Time for a beer and think on it.
Day 7, Reinstall original Master, Buy Pressure bleeder on Amazon. Might as well have a beer while I wait on Amazon.
Day 9, Pressure bleed the brakes, back to original problem. Grab a beer and back to the service manual.
Day 10. Hook up the Tech II and cycle the Rear Solenoids. Pedal is higher but still dropping slowly when coming to a stop. Park it and grab a beer.
Day 12. Hook up Tech II and cycle all solenoids, Pressure Hold and Pressure Reduction all 4 wheels. Brakes now work perfectly and pedal is up where it belongs with no dropping. I think it's time to celebrate with a Frosty Cold Beer!
Takeaway Lesson. 25 year old car, Cycle ABS solenoids once a year at the start of spring!
Cheers.
