Brakes

[ed209]

Hi All
I have been reading the arguements recently for and against drum brakes and as much as i would like a disc brake conversion along with lots of other silly and or expensive ideas i have decided to try and keep originality. However. . . after talking to a work colleague the idea of running a 'remote servo' to assist in the brakes has been suggested and that i would need an altenator off a transit because it has a 'vacuum'
Has anyone heard or better undertaken this?
SWB Series
2.25 Diesel and still very standard

[Rich_P]

What vehicle and year?  If you can tell me what vehicle and year it is, it may already have a servo fitted.  If it doesn't then on the late Series 2A straight six 2.6 Litre they had a remote servo under the air filter.

But you first need to tell us what Series it is, and what year.

EDIT:  Oh yes, a servo does not improve braking.  All it does is aid the effort required on the braking pedal.

[ed209]

1967
SWB

[Rich_P]

Okay, you probably don't have a servo unless a previous owner fitted one.  On the 2.25 Litre Diesel, Rover used a sort of flapper system that created a vacuume for things like a servo.  Unfortunately I can't say a lot more than this, as yours being a diesel is completely different to how a petrol's is set up.

[steve_h]

Hi, Do you still have standard drums up front, 10" diameter with one leading and one trailing shoe?

A servo will assist you in applying pressure to the brake pedal, but what is really needed is more effort at the roadwheel. One suggestion I've seen recently was to fit LWB REAR brakes to the front axle on a SWB. This gives you an 11" drum, marginally wider shoes but stays with the one leading shoe and one trailing shoe arrangement. This should give just over 10% more braking effort and the bits ar plentiful and quite cheap.

The next step up is 4cyl LWB front brakes. These again are 11" diameter, but have a twin leading shoe arrangement and wider friction material than the rears. The leading shoe bit is whats important. A leading shoe will, because of the rotation of the drum, force itself on harder (called self wrapping or self servoing). With two shoes doing this instead of one, these brakes should be much more effiecient, but only when going forwards. This is also the setup used on SWB models after about 1980.

The ultimate in series drum brakes is the 6cyl/V8 setup which is similar to the standard LWB front but with wider shoes (3"). These are the most powerful but hardest to come by. I have a stage 1 V8 front axle waiting to go on my S2A but it was stripped of brake gear long before I got it.

With regard to servos, they don't have to be remote. I have a complete servo/pedal assembly with dual circuit master cylinder from a late model S3 in my 2A. A remote servo is one that is not mechanically fitted to the brake pedal. You would only need this type if you didn't have room for the standard setup. I managed to fit mine OK with a little fettling of the inner wing.

You will need a vacum of some sort for any servo. On series diesels this came from a throttle type butterfly valve in the inlet that was closed when the accelerator was released. The vacum from the engine side of this was stored in a reservoir until needed. Modern diesels tend to have either a seperate vac pump (NAD/TD/TDi?) or an alternator with integrated vac pump (TD5?).

Hope that helps.

Cheers,

Steve.

[ian_s]

before i swapped to a 200tdi, i had a mechanical vacuum pump from a peugeot. worked a lot better than the standard system.

[12LDA28B]

In a standard SWB 2.25 diesel you have all the stopping power you need if your brakes are adjusted and working properly, assuming you don't need the extra efort that a servo will provide due to some disability?

Just make sure everything is adjusted and working as it should and you'll save youerself a lot of hassle and money.

[Batfink82]

during our current restoration (LWB 2.25 diesel series 3) my brother and i fitted a driven vacuum pump from a taxi. we used a military double pulley to drive it. we removed the butterfly valve and it seems to work really well providing alot of assistance to the pedal operation. the brakes are good enough to stand it on its nose. but that might be down to the complete set of new pipe work, shoes and drums.

[Devon-Rover]

Sounds like to me you would benefit from the twin leading shoes setup of a LWB, find a LWB axle and swap it over. If you did find a 6 pot version with the wider shoes then that comes with a servo too. Yours being a 67 might be lucky enough to have the modifield wing to allow the fitment of a servo. (from 67 onwards with the intro of the 6 they all had the same wings to allow this fitment be it a SWB or LWB)
The FC's though had a remote servo so it might be possible to find one of those but they are rare.
Any remote servo can do (just check how much force it applies) and being the diesel you still can get the butterfly valve that goes on the inlet manifold.

Of course you could look at why the brakes are not efficient as they should be able to pull you up nice and quickly. My last MOT showed that the front brakes were up around the 280 290 mark IIRC. my mums pug is only are the 330. I along side the rest of the rebuild last year replaced everything in the braking system down to remaking all my own piping.