In my articles on Brake Judder I included a bit on how to ‘bleed’ the brakes. Well even after doing this some owners still suffer from a soft pedal, spongy brakes or excessive pedal travel. After a lot of investigation by others, the industry, and myself I think I have the solution. This mainly applies to the Girling or FAG master cylinders but may be relevant to others. These cylinders have a bleed nipple near the end (furthest from the servo).

On right hand drive cars, there was insufficient room for a complete nipple so it was cut short or replaced with a normal bolt. The master cylinder should be bled from here before and after anywhere else; there won’t be room for a tube so you will have to let the fluid dribble onto a cloth on the down stroke of the pedal and then throw it away. Now on the installation of the master cylinder on the relevant cars the front is higher than the rear. This means that any air in the system will work its way to the top.

The top in our case is forward of the bleed nipple and is trapped, causing the problem. The paperwork with new cylinders says to prime the cylinder, or fill with fluid, before installation, this is one solution but not easy or ideal. Another solution is to get the back of the cylinder, where fluid enters and air can therefore leave, at the highest point. There are three ways I have come up with.

One is to raise the back of the, well chocked, car, with a jack, a very steep hill or both and operate and tap the cylinder until the trapped air bubbles into the reservoir.

Another way is to release the brake pipes near the cylinder, take the cylinder off the brake servo, complete with the pipe-work and bend the cylinder up, using the flexibility of the pipes, to release the air.

The third way is to relocate a nipple, on top and at the end, i.e. the highest point, by careful drilling and tapping. I have identified the problem and I know my solution is not perfect so please let us know if there is an easier way.

Alan Smith.