98 disco brake probs

I left my 98 discovery sitting for a few weeks, everything worked when i started it and took it for a spin except under braking it felt like the brake pedal was bouncing up and down, or being tapped by by something several times a second. this happens everytime the pedal is pressed but only whilst moving not stationary.

any ideas? help
Not sure if ABS is fitted how do i tell co z I know someone is going to ask

knackerd rear disc's if the front one's are shot you feel it in the steering and if the back ones go the brake pedal pulses

Aye it's probably either warped rear discs, or if your lucky just corroded/stuck brake caliper pistons after being stood up. T'is a common problem on Disco's.

Thanks guys, it gives me a warmer feeling

I have a 97 disco with ABS which suffers a similar fault although it is ABS related, as it is Intermittant and I can hear the ABS pump running when it happens.
The Pedal goes hard and bounces and it can happen at any time going quickly or slowly has anyone got any ideas, the ABS light comes on occasionally but I have checked the fault codes which were related to a sensor gap which has now been changed.
There was also a brake light switch fault flagged up but only once as brake lights seem to be active so I have ignored this.

I have EGR fitted but it has been blanked off but the vacuum hose and plug are still fitted to it.

There is a unit inside the passenger side wheel arch under the Chock which has pipes going to it could this be a source of the problem?

I hope some body can help Thanks, Timi (newbie)

Timi Tdi said:

I have a 97 disco with ABS which suffers a similar fault although it is ABS related, as it is Intermittant and I can hear the ABS pump running when it happens.
The Pedal goes hard and bounces and it can happen at any time going quickly or slowly has anyone got any ideas, the ABS light comes on occasionally but I have checked the fault codes which were related to a sensor gap which has now been changed.
There was also a brake light switch fault flagged up but only once as brake lights seem to be active so I have ignored this.

I have EGR fitted but it has been blanked off but the vacuum hose and plug are still fitted to it.

There is a unit inside the passenger side wheel arch under the Chock which has pipes going to it could this be a source of the problem?
I hope some body can help Thanks, Timi (newbie)

Click to expand...

Nope the part under the chock you describe is for the cruse control.

As for the brake problem when was the fluid last changed? Have your brakes tested at a good garage, not sick fit as will try to rip you off

gazdav said:

Nope the part under the chock you describe is for the cruse control.

As for the brake problem when was the fluid last changed? Have your brakes tested at a good garage, not sick fit as will try to rip you off

Click to expand...

I do not have cruise on my Disco!
I went through removing each of the wiring plugs spraying some WD40 and exercising them to make sure there was no corrosion on the contacts on the connections under the bonnet.

I removed the ABS relay and inserted a paper clip across pins 4&15 on the OBD II socket and checked the fault codes.

I got seven different fault codes two of which were not listed three were related to wiring faults. Three of which were to do with near side front and rear connection to the ABS ECU. Other two for sensor air gaps.

Noticing that the ABS ECU is mounted under the passengers side dashboard near ABS relay I remebered that when it went into the garage (the last and only time) the bonnet release cable got melted when wheel arch was welded I had changed the cable and may have knocked the connector to the ABS ECU. Long story short I removed the connectors and pressed them home again cleared the Faults and the brakes have been much better giving better pedal feel and response without the intermittant pump action!

So it some times pays (fingers crossed) to check all the electrical connections pull them out and re-insert to be sure.
Probably why there were spurious fault codes recorded.