Brakes, Pads, Pad Change, Fluid, Flexible Brake Hoses, Bleeding the System, Noises, Disk Removal Front,
Disk Removal Rear, Brake Lights

Brakes

Compiled by Fd

2 variants of brake system are fitted. Older cars have Metal Matrix Compsite (MMC) disks (an Aluminium, Ceramic composite) which require specialist pads. Newer cars have more normal cast iron disks, there are many pad options for steel disks.

MMC brake disks look like this, they are a dull grey colour and do not suffer from the normal red/brown rust that covers steel disks.

Pads

If you have the older MMC disks you have not option but to buy the special MMC pads from your local dealer. Using pads designed for steel disks on MMC disks will destroy them in a very few miles, despite this fact some dealers will, somewhat unbelievably, allow you to spec steel based pads for MMC disks, make sure YOU know.

If you have the newer iron disks then you have a load of options, depending on what you want from your brakes and how much you want to spend.

The OEM pads are said, by many, to lack bite. Bite is the amount of vehicle retardation that a given pressure on the brake pedal will result in. More bite equals more retardation for an equivalent pedal pressure.

Although the 'feel' of brake pads can be effected by many things and is somewhat subjective the following notes have been observed, comments are relative to OEM pads.

EBC Greenstuff V3 / V4

 

More bite, not too heat sensitive, not extremely durable in a track environment, relatively cheap, can cause terrible brake dust if you buy the V3 variant. Tend not to squeal. A good road pad.

Pagid RS4-2

 

More bite again, not too heat sensitive, fairly durable in a track environment, about double the cost of EBC but perhaps double as durable, brake dust is not a problem. Tend not to squeal once bedded in. A good road / track compromise.

Pagid RS14(obseleted) or RS15(replacement)

 

Yet again even more bite, need a little heat for efficiency, very durable in a track environement, similar cost to the RS4-2. Can squeal. A good track pad.

Pad Change

Look here to see an article about changing the front and rear brake pads.

Fluid

Lotus specify Castrol Super DOT 4 brake fluid, this is a fully synthetic brake fluid that exceeds the boiling point specifications of most DOT 5.1 fluids. It is no more costly than a DOT 5.1 fluid and has been used with no problems whatsoever by regular track day addicts. It is thought that using a more specialised DOT4 compatable brake fluid serves little purpose apart from costing more and requiring more frequent fluid changes.

Flexible Brake Hoses

The OEM flexible brake hoses are made from rubber, which is fine up to a point, however these hoses tend to expand under the hydraulic pressure from the brake system, this results in the effort from your foot expanding the hose instead of stopping the car. Primarily this reduces brake feel.

Fitting steel braided teflon hoses removes this flexibility from the brake system and gives a much firmer brake pedal and a much better feel to the pedal.

An excellent guide to replacing the hoses can ve found at http://www.elisenet.plus.com/BrakeHoses.htm

Bleeding the System

Probably the single biggest root cause of braking problems of the lot.

The Elise brake system is not easy to bleed using manual techniques, even the smallest air bubble trapped in the caliper will cause spongy brake pedal feel under extreme (track) use.

First point, use a pressure bleeder. Although the manual 2 man technique or 1 man bleeder kits can be used a pressure bleeder is not much more expensive and 10x as effective.

The front calipers really need to be removed to be absolutely sure of getting all the air removed, this is due to the design. Two pistons linked by a low link pipe causes air to be trapped in the inner piston unless the caliper is inverted (allowing the air to move through the link pipe to the outer piston recess), re-inverting the piston back to normal orientation and finishing the bleed will ensure that all the air is removed.

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Noises

Clunks on application of the brakes can be caused by a number of things, one thing worth checking is the anti rattle spring on the front caliper. The anti rattle spring can be fitted incorrectly (backwards) causing the pads to move in the caliper every time the brake is applied. Look here to see a picture of the spring correctly fitted.

Often confused with rattly suspension the pads can rattle in the front calipers. Later cars have small pad 'buffers' fitted to dampen this rattling. Look here to see a picture of the caliper, the red markings show the location of the anti rattle buffers, these are self adhesive and can be obtained from the dealer.

Clicking, often caused by grooved or driled disks can be caused by the pads picking up on the drillings on the disk surface, the anti rattle buffers described above can be used to solve this problem.

Disk Removal Front

To remove the front disks you must remove the front brake calipers, to do this you must undo the two caliper retaining bolts, pictured here, and withdraw the caliper from the upright. Be carefull, the retaining bols are steel and the front upright is aluminium, you must make sure not to damage the threads in the upright.

Once the caliper is removed the disks can be removed, some will simply fall off the hub, some will require some significant effort to move. For stubborn disks you must use a hammer, knocking the disk then rotating the hub say 45degrees and repeating, slowly knocking the disk off the hub. If you intend to re-use the disks you must use a soft faced hammer (plastic/rubber) otherwise you will damage the disk surface, if the disks are getting ditched then a metal hammer will be fine but be careful, the disks can shatter, and yes you may hae to hit them that hard.

Refitting is simple, but make sure the hub face is operating theatre clean otherwise you can get brake vibrations later on down the line. To ensure the hub is clean enough use some fine grade emery paper to remove all corrosion before refitting the disk.

Refit the caliper, making sure you have pushed back the caliper pistons, and use some Permabond A131 on the steel retaining bolt threads, this prevents corrosion which can seize the bolts in the upright (electrolytic corrosion) and ruin it. Bolt torque is 45Nm, use a torque wrench as this is not as tight as you may think, overtorquing a steel bolt in an aluminium component is easy and will destroy the threads in the aluminium component, in this case the upright.

Disk Removal Rear

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Brake Lights (coming on by themselves)

A relatively common problem leading to a flat battery. For one reason or another the brake light switch seems to get out of adjustment and can power the brake lights (which are live even without the ignition on) when you are not around (overnight for example).

The switch itself is accesssed from the front services compartment, pictured here (picture taken looking toward the rear of the car from just in front of the brake fluid reservoir), and is adjusted by twisting the switch, pulling it in or out as required and twisting again to lock in position. Always test the brake lights still work after any adjustment.

Disclaimer : All information is supplied as a guide only.
No Guarantee as to its reliability can be issued.
You use this information entirely at your own risk.

No Reproduction or Reuse without prior written consent.

© Elise FAQ Team 2002