PeterH
14th April 2014, 06:14 PM
I've been at it again today, trying to diagnose a fault with my cruise control, where it would not hold speed, or lately work at all.
I could not hear the little click any more when I pushed the set button and had no cruise control.
The first thing I found was the cable was out of adjustment, which is an easy fix, (see pics).
Next I got under the foot well and found the vacuum switch that rests against the brake pedal was loose in the bracket, thanks to a tiny broken clip, the movement was enough to stop the switch properly engaging.
I followed this guys idea and it worked a treat, a small screw in the end of the plunger effectively gave me enough adjustment to get it working again, I could once again hear the click when the set button was pushed.
Cruise Control Patch/Fix, Brake Switch (http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/37946-cruise-control-patch-fix-brake-switch.html)
Next I checked the hoses were holding vacuum ok, which they seemed to be.
So I tested the electrics of the pump following this thread: P38 1998 Cruise Control Fix (May help someone) (http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/45804-p38-1998-cruise-control-fix-may-help-someone.html)
I found the pump to be working correctly, but it would not hold vacuum.
Finally I traced the vacuum leak to the bottom short hose on the actuator (arrowed in the pic). I had replaced the two short hoses recently, but the bottom one was not sealing properly.
I had a smaller gauge hose laying around in the shed, so I cut that to length, put it on, went for a drive, and hey presto, cruise control working once again, and it didn't cost a cent to fix.
Hope that helps someone trying to diagnose a cruise control fault.
Cheers, Pete.
I could not hear the little click any more when I pushed the set button and had no cruise control.
The first thing I found was the cable was out of adjustment, which is an easy fix, (see pics).
Next I got under the foot well and found the vacuum switch that rests against the brake pedal was loose in the bracket, thanks to a tiny broken clip, the movement was enough to stop the switch properly engaging.
I followed this guys idea and it worked a treat, a small screw in the end of the plunger effectively gave me enough adjustment to get it working again, I could once again hear the click when the set button was pushed.
Cruise Control Patch/Fix, Brake Switch (http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/37946-cruise-control-patch-fix-brake-switch.html)
Next I checked the hoses were holding vacuum ok, which they seemed to be.
So I tested the electrics of the pump following this thread: P38 1998 Cruise Control Fix (May help someone) (http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/45804-p38-1998-cruise-control-fix-may-help-someone.html)
I found the pump to be working correctly, but it would not hold vacuum.
Finally I traced the vacuum leak to the bottom short hose on the actuator (arrowed in the pic). I had replaced the two short hoses recently, but the bottom one was not sealing properly.
I had a smaller gauge hose laying around in the shed, so I cut that to length, put it on, went for a drive, and hey presto, cruise control working once again, and it didn't cost a cent to fix.
Hope that helps someone trying to diagnose a cruise control fault.
Cheers, Pete.