cruise control issue - please help

Hi guys,
As you may or may not know i picked up my Disco 4.0 V8 ES on Sunday.
Since then i have discovered a few issues with the car.

one being cruise control. When i set the cruise control i can almost feel the car "hopping"? and i notice that the speed actually starts to gradually get slower (still on cruise though not released) just gradually getting slower over time.

is this common? can anyone advise anything to check?

Thanks

The only one I had that actually worked did the slowing thing and that had PVC pipes sealed with silicone.
Anyway,pipes first_replace the rubber ones....then the bellows actuator thing- does it have a diaphragm?(never looked),then the pedal switch,after that the compressor located under the jack...Im just guessing here cos I never bothered to fix one that didnt work but that should give you a starter.....
Come on lads,back me up here!!!

Thanks for the info did a little more testing today it looses about 10mph every 1mile.. crazy!!! are these pipes a DIY thing to change or do i need a dealer or specialist ? expensive?

The pipes/hoses are a definite DIY however un-mechanical you are....source some nice cheap 6mm/quarter inch PVC hose...aquaria/windscreen washer etc,doesnt need to be expensive or reinforced or fuel or food rated,and replace the ones on there,smearing some silicone sealant on the joints as you assemble.
You are looking for a hose that runs right across the back of your engine bay with a T off through the bulkhead to a pedal.Follow it round past the air filter box to a little electric compressor under the jack,or where the jack should be.

Your first move should be to do a search of this site to see what hints you can pick up.
Good luck!

shocksie :welcome2:

Yeah, sounds like you have a split/leaking vacuum line. No problem to fix that but I would also be inclined to check the operation of the solenoid valves on the pump, fairly easy to hot wire with a couple of short jumper wires.

If there is a hole in the bellows, hotwiring the vacuum pump should enable you to hear if it is leaking - run pump to operate throttle, stop pump and listen/watch. You might have to fiddle about a bit to figure out which terminals you need to put power on to control pump and solenoids but is fairly easy. I did it on my Classic without too much difficulty.