Rolls-Royce and Bentley Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
Hi. I'm working on a 67 MPW 2 door and have a couple of questions that I hope someone can guide me on. I've just replaced the two accumulator spheres and took off their valves to facilitate. Spheres were very tight! Anyway, all back together and I've only bled system 1 so far and (surprisingly to me) both brake lights are already behaving correctly. I'll do system 2 shortly but my first question is do I have to bleed the rear height control rams and if so can it be done with the wheels off the ground? The car is on axle stands under chassis front, trailing arms rear, wheels off.

My other question is whether or not I can get away without bleeding the low pressure (m/c) system.

Many thanks in advance
Mark
 

·
Registered
Joined
·
1,812 Posts
My car is a Silver Shadow 11 which doesn't have a master cylinder so I'm not sure about bleeding to MC but I think it can be done by opening the relevant rear caliper bleed screws and pumping the brake pedal as one normally would with a conventional brake system, can't recall if the lower or upper rear caliper bleed screws are connected to the MC but the manual will offer more clarity. With regard to bleeding the height control with the car resting on the trailing arms bear in mind that the trailing arms will rise and fall when the ram bleed screws are opened or closed once the height control levers move so there a risk of the car toppling off the jack stands. It's a lot safer with the wheels attached and resting on a sound surface and with the front wheels chocked so that the car can't roll. Both brake lights behaving correctly is an indication that there's pressure in both accumulator control valves but it doesn't confirm that all the air is bled out of the systems.
 

·
Registered
Joined
·
2,382 Posts
Shadows with MC have their own hydraulic circuit with bleeders in the rear.
The workshop manual is easy to follow and includes all the pipework as well.
 

·
Registered
Joined
·
2,108 Posts
Personnally on my Shadow I, I never bled suspension, it is supposed to be done by itself. Bleeding might create troubles, noises...

You need to bleed low and high pressure on calippers. Low with classic pumping, high with engine iddling.

You should also open your brake pressure switches and clean them and probably check plunger free to move and replace diaphragm inisde.
Often they are stuck a give wrong information regarding pressure.
 

·
Moderator
Joined
·
621 Posts
You should definitely bleed the master cylinder and height control systems to remove old brake fluid from those systems. All the systems should be flushed and bled every two years, this will ensure the brake fluid is completely replaced so water that has been absorbed into the brake fluid throughout the system is removed before it causes corrosion problems. Shadows are particularly bad for absorbing water into the braking system because of the large surface area of the brake fluid reservoir.
 
1 - 6 of 6 Posts
Top