Felt a brake pedal sink on a test drive in Tulsa, and what I found under the truck still bugs me | Auto Mechanics - Freelance Forum - The Community for Independent Professionals
Felt a brake pedal sink on a test drive in Tulsa, and what I found under the truck still bugs me
Had a 2011 F-150 come in last Tuesday for a brake job, and the owner swore the pedal felt soft for a month but nobody could find the leak. I pulled all four wheels in the bay, checked the lines, checked the calipers, dry as a bone. Took it for a test drive on the highway loop near the shop in Tulsa and the pedal went almost to the floor at a red light, so I limped it back doing 20 in the shoulder. Turned out the master cylinder was leaking into the brake booster, and the fluid had been getting sucked into the intake for who knows how long. The reservoir was low but not empty, which is why the last two shops just topped it off and sent him on his way. I ended up replacing the master, the booster, and flushing the whole system, and the pedal came back firm as new. What gets me is he paid two other shops $180 in diag fees for topping off fluid, and neither one pulled the master to check the back seal. How do you all sell that extra diag time on a soft pedal when the lines all look fine? I want to hear how other guys handle it without scaring off the customer.
Man, I heard a guy on a podcast say the same thing, that master cylinders leaking into the booster are the number one thing shops miss on a soft pedal. His trick was to pull the master off and look at the back of it, takes ten minutes and saves you the comeback. Problem is you gotta charge for that time and most folks don't want to hear it.