13 replies to this topic

[Sprocket]

Seems daft that Rover fitted a brake servo, when after driving a car with disk brakes with out one, the feel of the pedal was no different to my car with a servo. The servo takes up far too much room in an already cramped engine bay, more so on the injection cars.

Im considering replacing it with a standard yellow band master cylinder, giving me more room for extra bits for the turbo conversion.

Any one out there know the real reason, or is my servo duff, not that it bothers me, the brakes work fine.

[vasi]

No, your servo is not duff. Yes they are useless in my experience too. Unfortunately, I can't advise why they were fitted. The only servo I've ever had on a mini that was any use was a remote type one. And I was gutted when the diaphragm ripped.

[Bungle]

yep i have been towed in my mini and with out the engine running the braking is no different

[minidaves]

then something is a miss the servo on a late mini when working is great, however most seem to be full of brakefuild from leaking master cylinders

dave

[Bungle]

but even from new my servo didnt seem to do anything

[Sprocket]

No, my servo deffo works, its just there is no difference in pedal feel between cars with or without

[Guess-Works.com]

The bottom line is that they tried to make it "modern", the same as the verto clutch is softer, and then on the metro they put the clutch damper thing which made it even softer...

I defintely noticed the difference when I had a remote servo on the 72' ala cooper S stylee... when on drums it was useful, when I changed to disks & 4 pots, it was about 2 weeks later and the servo was out. Could not get the feel of the disks at all, but once it was out, ah solid pedal and responce from the brakes.

Edited by GuessWorks, 12 January 2006 - 12:21 AM.

[DaveCoxon]

I can certainly tell the difference between servo'd and non-servo'd 8.4: discs...

If you can't, try pressing the predal on the right a little harder, THEN try the middle pedal... You will notice and appreciate it at motorway speeds.

[Wil_h]

I agree with Dave. My road mini had a servo and my hillclimber dosen't; in a blind test it would be VERY easy to tell which has the servo.

Bungle, the servo won't work with the engine off!!

[Dan]

That's what Bungle meant, he was saying that that's how he knew it was no different (although it will work for three or four pedal presses, so maybe he didn't have time to run out of vacuum if he was only towed a short way?).

I agree with Guessworks that they probably fitted it because all other cars had one at the time. Althoug it may be that one of the important territories for Mini (Japan or Germany) required power brakes from '88 and they had to fit it to all territories to justify the expense of developing it. It does make a real difference, as Dave says if you are at high speeds. You'd notice in an emergency if you didn't have the servo, when you jump of the throttle and onto the brakes there is an immense engine vacuum (from the throttle snapping shut with the engine turning fast) which really pulls the brakes on fast. You just don't think about it as in an emergency you're probably thinking about something else.

The system would work a lot better on the Mini with a vacuum reservoir fitted, as the engine is quite small with a very small inlet manifold as compared to other cars you tend to run out of vacuum too fast. There's more volume in the servo chest than there is in the inlet manifold, so the vacuum is destroyed really quickly.

Edited by Dan, 12 January 2006 - 09:59 AM.

[Pooky]

So what's the final verdict? :erm:

[Wil_h]

So what's the final verdict? :erm:

If you have one leave it where it is and if you don't have one don't bother fitting one.

Exceptions being: if you want to take weight out of a racer bin the servo and if you have a wooden right leg the servo might be worth adding if you didn't have one.

[Jackman]

Seems daft that Rover fitted a brake servo, when after driving a car with disk brakes with out one, the feel of the pedal was no different to my car with a servo.

Are you on about my brakes here?? If so were they that good?

[pdaykin]

They fitted brake servos on minis for the same reason as on polos - to reduce the effort on your leg

The cars were aimed at ladies (sorry girls) and, as I understand it the strength/effort needed to apply the brakes was too great when compared to other small cars (IIRC the polo was the last of the successful small cars not to have a brake servo)

The use of a servo means you can alter the master cylinder bore to reduce pedal travel too

Just as an example, I have a few early minis. My now Mrs nearly smashed up the '64 as she pressed the brakes and went flying on at a junction - she simply wasnt used to the pedal effort and travel required as it was the first old car she had driven. Despite its drum brakes and no servo, I can quite merily apply enough effort to lock the wheels. However, when you are trying to sell a NEW car (as the Rover would have been in the 80's) trying to pursuade a customer that you have to work a bit harder isnt really going to do your sales figures any good !!!


I those of you that are saying you cant tell the difference in pedal feel are serious and not just saying that for the sake of making a point you need to get your braking system checked - it is increadibly noticable.