Dov808Dovydas Vijunas
3hHello guys,can’t find problem with my XK150 automatic gearbox. I did full restore 8-9 years ago.
Few weeks ago noticed under dashboard smokes after turning on lights. Removed dashboard-found wire from rear plates lamps was the problem,change it,problem gone. But after short drive got bigger problem wgich i can’t resolve till now.
After night if i select on N,i can roll the car.After short drive car starts to feel very slow,gears selecting not normal from 2 to 3,even some noises in gear i can hear. So after this on N car is blocked.
I read about that it could cause anti-creep system. Electrical switch was working,so decided to remove anti-creep brake solenoid. Same no help
In the left side i got switch,it’s written overdrive,but i think its intermediate speed Hold, it’s working if switch in-then i got 2 gears,and when its out -i got 3 gears.
Servo filter is clean.
Vacuum reservoir also seems good.
Got another brake cylinder from another xk150 -maybe try to change it?
Thanks for suggestions.

 

You may have a brake hose problem. Old hoses will swell internally and you can apply brake pedal pressure but there is not enough back pressure from the wheel cylinders to get rid of the pressure.
After sitting for a while the pressure may bleed off in the wheel cylinders and the car can be rolled in neutral.
Check the wheel temperature after driving. A hot wheel will be the one dragging the brake.
From your description I suspect the rear hose to be the culprit.

By the way I have just gone through this hose problem in my Series 3 XJ6 and have encountered this in numbers of other cars.
Cheers

 

I had a similar issue on my MK 2 with virtually the same symptoms which came on. Rather suddenly.
The problem in fact was in the piston in the brake servo unit (which was not the original servo). The piston had collected enough corrosion or other gunk on it that the brakes were sticking. Filter removed, piston lightly cleaned with1000 grit paper, issue solved!

 

Also, make sure the one way valve in the vacuum line is working. If it isn't, the air-vacuum piston drys out and sticks and the chamber wall suffers. As a short term fix, a little brake fluid poured down the air line from the filter to the servo can free up the piston.