A niggling brake problem

There has been a rather annoying problem with the braking system of the DHC over the past years. It started a few years after the cars restoration was finished. Initially I thought it was caused by the (inferior quality) front pads I had to fit after the Mintex M1144 pads wore out within 8.000 kilometres. In the end I overhauled the complete braking system. And with every new or reconditioned item fitted, and after every bleed session, there was an improvement. I even went as far as “manually” adjusting the rear brakes. But despite all the efforts I was still left with a very light and rather vague pedal feel. And the pedal travel was still too long for my liking. The brakes performance and balance was fine though, as a few checks on a friends brake test bed showed.

And that was when Covid struck and the problem was temporarily forgotten. Till I visited the previous mentioned friend's workshop with the DHC a few weeks ago, and I mentioned the problem. He knew what I had done to the cars brake system, so he didn’t do any suggestions. He only asked if I had fitted anti squeal shims between the pads and the calliper’s pistons. He had some problems with a car’s braking system recently, and removing the shims solved the problem. That’s what started me thinking!

When I restored the car I only used the self-adhesive anti squeal foil provided with the Mintex pads. And during the two Alpine trips that followed these were burned away. And the hotter the brakes got, the better they performed. And giving a very good, direct pedal feel.

This fact was overlooked at the time when I fitted the new pads. As a result I used the original fitting kit for the various replacement pads, including the steel anti squeal shims. Time to get the spanners out. Well actually drive over to a friend’s workshop and use one of his lifts and tool trolleys.

This made life so much easier! And within a few minutes all four pads were stripped of their anti-squeal shims and pads.

As you can see in the picture above, there is a fair amount of possible movement and slack in the system with these fitted. So I followed the given advice and removed both the shims and adhesive foil from the back of the pads. After which the pads were put back in the callipers, using special high temperature ceramic brake pad paste as a remedy against squealing pads.

Driving home afterwards again showed a tiny improvement. And driving the car a few more times in the weeks after it did improve it slightly more. But still not what the brake pedals feel should be. Time for the final task (hopefully). As it was well over 2 years ago that the brake fluid was changed, it was time for a traditional two person fluid change and bleed session.

This time I made sure I used the correct sequence: First the front calliper furthest away from the brake master cylinder, followed by the other front calliper. And finally the back axles single bleed point. And sure enough there were a few air bubbles that came out of the rear bleed nipple after a few strokes from the pedal. Could well be the culprit, especially as the brake’s performance was equal left to right on both axles. A test drive should hopefully provide a definitive answer! At least I should have some time for a test drive soon, as my holiday has started today! To be continued (and another possible culprit for the longish pedal stroke sprang to mind yesterday 😶).