Brakes - Servo too.

[fastblatt]

Hi.
So I'm getting to grips with the new addition 2000. The brakes are crap basically (heavy). Sometimes i feel the Servo is not working all the time (solid and scary). The car has single line brakes. Is the braking better for a duel line car? And also is the servo just for  single line brakes on the 2000 or will other servos fit (ie stag) I am sure the servo is leaking air somewhere as you can hear it under the bonnet when you switch off but I don't know where from.
Any help or comments appreciated.
Mark.

[mikeyb]

solid and scary sounds like a knackered servo.  I dont think dual line braking will feel any different.  I think that you will have to fit the stag master cyl with a stag servo - which means conversion to dual.

BMW ones have also been made to fit by others, can't recall which model though.

[AlanChatterton]

Check to see if servo is working.

Pump the brake pedal several times until it goes rock hard...... servo is now empty of air.

With one foot on the brake pedal, start the engine. As it fires, the brake pedal should drop a couple of inches. If it does, servo is fine. If it doesn't, servo is toast.

Stag servo is different so you need stag servo, master cylinder and then a re-plumb of the pipes for dual, but it really doesn't give you anything.

I suspect your servo is u/s, or the hose to it is leaking, which is the hiss you can hear.

[fastblatt]

Hi
Thanks for the swift replies. Most of the time the servo is working but the brakes are nowhere near as good as the stag brakes. I think there may be a slight leak which is taking away the efficiency. It is only 2 or 3 times that the brakes have gone hard, usually after a start up at the end of the road. My foot definitely feels it if I have been driving the car for 20 mins or so. I'll look around it again and may punt a second hand one if I can't find anything.
Thanks
Mark.

[Richard B]

Could be because Stag brakes are much better....


Larger diameter discs

Wider drums and shoes

Bigger servo

Twin pipework

[Doug Thompson]

If you've only just acquired it what are the front pads like , also the rear cylinders could be seized/partially seized :)

[fastblatt]

Just been through an MOT so rears are OK. Car was standing for 15 years just after rear wheel cylinders were replaced. I thought the front brakes were the same as stag. My mistake and now I realize they wont be so good as the stag. Still think the servo should be better. I'll have a look tomorrow.
Mark.

[thescrapman]

My green PI had brakes that were very wooden.

Replacement servo solved that.

Now need to solve the "odd" brakes on the 2000. Massive over assistance on the first push and then like pushing a lump of old oak through the bulkhead on teh next push.

Cheers

Colin

[Nick Jones]

Don't forget the one way valve in the manifold to servo line.  May be built into the plug-in elbow where the hose enters the servo.  If this is not working well then assistance can be variable.

Nick

[fastblatt]

So.... are all servos equal? Are they the same for all mk11's or are the servos for the duel circuit brakes different to the single line brakes or does it vary between 2000 or 2500 cars?
Thanks
Mark

[AlanChatterton]

All MKII servo's the same. MKII (UK market) never had dual line, only Stag.

[fastblatt]

Thanks Alan. Shows what little knowledge I have of these cars.
Mark.

[andy thompson]

Mk2 dual circuit have 13/16" mc , stag has 7/8". Both use the same servo (different in detail to single circuit but same assistance).

[fastblatt]

Ok. Had a look yesterday and removed the master cylinder out the way and the servo has a slight leak from the center pin with the engine running so it is probably reduced efficiency and sometimes no efficiency. Ill get another one and go from there. Thanks for your help folks.
Mark.