Brake Problem

Pedal went soft, like failed master cylinder.

Replaced MC, bench bled, bled in truck with liners at MC loose. Pedal still feels soft, but truck stops and stops fine with 5th wheel. Pedal does not go to floor but close. Brake light does not come on. Ebgine off, pedal fells soft on initial push, pumps up like bad MC.

What year? How many miles? If it has drum brakes on the back, the self-adjusters could have failed, which will confuse the master cylinder…Pulling the rear axles and drums to check is quite a job…A good brake man might be able to manually adjust the rear brakes without pulling the drums, but an inspection is probably wise if you are pulling a big trailer…Now and then, a rubber brake hose can “balloon” without leaking, making the pedal soft…

I’m sorry. It’s a 1999 w/ 116k, 4 wheel disc w/ ABS. Also had a 4 wheel brake job by Ford 2 years ago. I will check the hose when I return home Wednesday.

There are at least 3 “flex lines”. One to each front caliper and one between the frame and the rear axle housing…This is a long-shot… To check them, have someone step on the pedal firmly while you inspect the flex-lines for any bulges. Next step should be to bleed the entire brake system. With the early ABS, there may be a special procedure to do this…

There are four. The rear wheels are on separate hydraulic circuits due to the four-wheel ABS.

Tardis is correct…Each caliper will have its own flex-line…

Thanks tardis & Caddyman. I’ll get on it Wednesday evening and let you know how it goes. I read one procedure that requires a scanner to activate the ABS valves. Any way around this?

Checked all the flex hoses and brake lines. All good. Had the system flushed - brakes feel just like they did before. I’ve never understood why the older Ford trucks had so much pedal travel with no real stopping point like the newer models.
As long as it stops everything when I tandem pull, I guess it doesn’t really matter.