BKD 140 PD. Occasionally the brake pedal travel increases....come up to a junction and brake pedal travels further to floor...brakes still work, a couple of pumps increase pressure and stays that way. Happens occasionally with no pattern. Any ideas ?

Edited 2 December, 20187 yr by banjax34
Additional info

Check the calipers/hoses for leaks.

 

If you find brake efficiency diminished, check the vacuum pipework from the tandem pump. The metal pipe fitting is notorious for becoming loose as is the hard plastic pipe for splitting.

Cheers , will have a look tomorrow

If there are no obvious leaks then I'd be thinking  that the calipers are getting some push back or lazy master cylinder seals (internal master cylinder leak) or at worst, the ABS valve block is leaking internally.  I've also seen this symptom when the proportioning valve is corroded stuck but i don't think the Octy has one of those.

 

If the former, make sure there's no runout or thickness variation in the rotors.  Also, make sure the slide pins are moving freely and the pads aren't corroded into the caliper carrier.  You might also peel the piston boot back and have a look to ensure there is no dirt / corrosion (yes, lots of these things will cause the opposite to a long pedal but if you cover the simple, basic stuff....