My '03 Disco without ACE has sat for a few months while I sorted some engine issues out. Now that I'm back on the road I've noticed the brakes are very weak. They felt spongey as if there were air in the system however when placing mild pressure on the pedal I could engage the ABS system (pulsing of pedal). This weekend I gravity bled the brake system with Valvoline synth DOT 3/4 fluid at all four corners. This helped quite a bit as I am no longer engaging ABS but I still have fairly weak brakes.

They seem to be weak at speed and at idle and the ABS pump still kicks on and off at startup. The three amigos are on as well and I don't have a ABS code reader on hand to pull the code. Anyone have any idea of where to start?

 

How many miles on the truck, who's brake pads are you running, have you ever replaced your 6 rubber brake hoses and how much fluid did you gravity bleed thru?

 

I've only had the truck 4-5 months max so I'm unsure of the brake pad spec. I would'nt have thought a modern ten year old truck would need brake lines changed out already...

I did a gravity bleed until the new fluid started showing at all four corners. Starting with the back passenger to driver to front pass and then driver wheel.

Its seemingly doing better a day after so I may gravity bleed one more time and see what happens.

 

Do an old convential bleed while having someone pump the brakes, you will get more junk out of the lines.
As for the rubber brake lines, got to remember these trucks are from the UK where nothing makes since. I will tell you though if you want a lot firmer pedal, replace all six rubber hoses.

 

I have found that the brake servo hose was loose where it enters the intake manifold. I ordered a new valve with a red clip and swapped the red clip over. That noticeably helped with my weak braking. I still have weak brakes and when I stand on my brakes I can hear a hiss in the background as if air is being let out somewhere. Does this mean that my brake booster may be an issue?