Brake Pedal Fade (Intermittently)

[Big_OGD]

Dear Members,
My beloved 3.0V6 Diesel Portfolio has just recently had a complete brake pad and disc replacement. However, in last couple of days when car is in traffic and crawling ie. low revs the pedal travel when pressed is almost to the floor.

I have taken it back to the dealer who did the change and the fluid is still as normal, there is no fluid discharge at the nipple or brake calipers and they cannot find any other issue.

It stops on a button under normal braking conditions but this is the first time I've experienced this after nearly 2 years of owning the car and I am just after a bit of advice from anyone.

Regards,
Owen

[Raistlin]

Possibly, the diaphragm in your brake servo has been contaminated by brake fluid from the master cylinder, or youe brake servo vacuum pipe is damaged.

Try getting up to a speed of 30 - 40 mph then pressing brakes on and off several times. If the braking effort suddenly changes then the above is almost certainly the culprit The vacuum reservoir is beingf depleted faster than it can be replenished.

[Big_OGD]

Garage managed to duplicate fault and re-check the pipes and bled the system just for good measure. Problem still there and we're now changing the Master Brake Cylinder as step one of the diagnosis manual.

Good news for me is that it's covered under my warranty package.

[Raistlin]

Fingers crossed it is the master cylinder 🙂