Drum Brakes – How to get them to work

 Important – the following is a brief account of how I have made the brakes on my cars perform better. If you take this information away and use it, then you do so entirely at your own risk.

 Disc brakes are expensive if you want to stick to ten inch wheels (and even more so if you want to keep the wheels under the wings without adding arches), but are seen as a must for any slight tweak in performance of a drum braked car. But this does not have to be the case. A number of easy modifications and good house keeping can resolve these issues to make dodgy drums a thing of the past.

 The whole system needs looking at, but taking each individual component at a time. I will deal with front brakes first, then the rear

 Front brakes

 The pedal – BMC used two different pedals in the mini, one for drums and one for disc brakes. The difference is that the one for discs is made from thicker material and is set at a different angle to allow for longer travel. By simply swapping the pedals you can give your self more travel so you don’t hit the floor so soon. The later disc pedal is also like this, but the bit your foot sits on will have to be cut down if you want it to look the same. While I am on with pedals, a quick note about the clevis pin at the end – ensure that when fitted the split pin is bent well out of the way - if not it can catch and reduce pedal travel. This applies to the clutch as well and can lead to an intermittent slipping clutch.

 Master cylinders – just need to ensure that these are in good condtion. It is not worth while fitting an S item as it only holds more fluid, but has the same sized piston. It was fitted as discs will use more fluid as the pads wear down.

 Brake fluid – Needs to be in good condition. We use racing brake fluid, having managed to boil DOT4 before. I have also have not been too impressed with synthetic fluid, as this gave a spongy pedal feel in our midget, but that was about ten years ago and I would hope that things have improved since then.

 Pipes – ensure that these are in good condition with no corrosion. If you are not bothered about concourse, use copper pipe and brass fittings. Replace the rubber hoses with braided items as this reduces expansion of the hoses. If you are fitting bespoke lines, for example running the lines inside the car, then use as much solid pipe as possible. Braided hose will still expand and will be more noticeable over a bigger distance causing a spongy pedal. I only use braided hoses at the wheels, even with all the lines inside the car. Keith Calver has some good comments to make on this

 The brake units – these need to be in good condition and kept adjusted and cleaned out frequently.

The adjusters often seize and become rounded off. To un seize, strip the brakes down and use something like mole grips on the inside cam to loosen, working in release oil and copper slip. If the spanner square has rounded off, welding on a 5/16 nut works a treat.

Slave cylinders – not a lot to say on these, just to make sure that they are not seized. The Works teams used to run them without the paper gasket at the back to allow for effective heat dispersion.

All the springs, etc should be in good condition

 Drums – should be in good condition. Minifins are supposed to be a lot better at heat dispersion, but I do not have any experience of these. Use stainless screws to hold the drums to the hubs; it saves a lot of time and cursing. The works used to drill holes in the hub face too let the dust out - I have yet to try this but it is on the list.

 Shoes – Fit performance shoes to reduce the prospect of brake fade, These are the one of the best performance aids we have added to the car, and have not suffered fade since, and this is why I now use racing brake fluid as the system gets much hotter. Available from catmint.biz

 Servos – not had any experience of fitting these, but it should work OK. Vizzard and Clive Trickey mention fitting of servos on drums.

 Rear brakes

 Same principles apply as the front brakes, plus a couple of mods

 Adjuster – renowned for seizing in place – an easy way to prevent this is to remove the adjuster, take an old rubber cap from a front ball joint and fill it with grease, place it on the back of the back plate, but in front of the cross bar and then screw the adjuster back in with a dose of copper slip. This keeps the back of the adjuster immersed in grease and the elements out.

Hand brake – needs to be kept adjusted to be effective and the quadrants kept free. I have modified these with stainless bushes before but was a sod to do, but worked.

The hand brake lever must also be kept free to move, a good dose of copper slip worked into the joints helps. To get the handbrake more effective the arm to the clevis pin can be extended by about half an inch to obtain more leverage.

 Finishes

 Just a note on painting the drums – use a heat resistant paint on the drums and hub, they get HOT. Do not powder coat, as this burns off creating a big stink, and when you come to pull the drum off, it is glued to the hub. Powder coating is OK on the back plates, etc.

 And finally Adjustment – no matter what you do, if the system is not kept adjusted, frequently serviced and free of air, then the brakes will not be as effective – if in doubt, read the Haynes manual to get it right.

REMEMBER - YOUR LIFE, AND OTHERS, DEPEND ON YOUR BRAKES WORKING PROPERLY - DO NOT CUT CORNERS. IF YOU ARE NOT SURE, SEEK ADVICE