Any time a customer works on their own car before bringing it to you, you’re not sure what you’re going to find. SureTrack community member schoolhouse2021 had a Ford Explorer in their shop where the owner had replaced the brake booster and master cylinder themselves, but the brake lights were now stuck on. A spongy brake pedal led them to look at various causes. They posed the question to the community, and with the help of fellow community member Lanpro1 and others, they were able to resolve the issue quickly.
The following Community Fix summarizes the interaction between members of the community that led to the solution.
2011 Ford Explorer Limited 3.5L
Brake lights stay on, spongy pedal, replaced booster, caliper and switch.
Customer complains that brake lights are stuck on.
Diagnostic Steps Performed/Parts Replaced
Customer did their own brake booster and master cylinder and now the brake lights stay on at all times. You can get them to go off by pulling pedal up by hand. Obviously this also means that you can start the car (Push start) and shift car (Automatic Trans.) without pushing brake pedal. The brakes are also extremely spongy to a point that it is dangerous to even drive it. Customer didn’t bench bleed master cylinder so we first pulled lines off master cylinder and bench bled it in the car. We also bled ABS pump with scanner and bled each of the calipers as well. Seemed to make a difference but brakes are still pretty bad. The rear calipers seem to also be releasing to much when you let off brakes. You can pump them when you are on road to get pressure but once you stop its like starting over. As for brake light issue we have tested brake light switch and wiring and found no issue. Seems there is some play in the whole assembly but can’t believe it would choose now to become an issue. Where to go from here?
Best Answer from Community Member Lanpro1
Try and clamp off the left rear brake hose and see if it is better. If it has the park brake built into the caliper, I have had them suck back in when off the brake pedal.
Replacement booster not working, brake light switch was broken when customer installed booster. Caliper bad as well.
First replaced booster with factory booster and it helped a good bit with pedal. Replaced caliper and spongy pedal problem was completely fixed.
SureTrack® is a powerful value-added feature available with select Snap-on diagnostics tools. It offers an exclusive combination of expert knowledge and detailed parts replacement records, all wrapped in an interactive community.
Want more? Click here for more information on using SureTrack.
New or Expired SureTrack users: Click here for authorization key instructions.