Well driving the Elise one Sunday I applied the brakes to slow going down a hill and the pedal went to the floor. I’d had no warning of a long pedal or spongeyness in the pedal prior to this, I just applied the brake as I had done moments before but this time the pedal kept going and so did the car! Fortunatley I was just slowing into a 30 limit and had nothing stopped in front of me meaning some engine braking and light application of the handbrake slowed the car just fine. This was still very alarming though!

I pulled over and gave the brake a few pumps which brought some pressure back into the system then got out and went looking for any brake fluid leaking. I couldn’t find any evidence of a leak so let it cool and and pumped the pedal some more. It felt much better and I was only 1 min from home so drove it home carefully.

I got the Elise up on the lift and went looking for any evidence of a leak but still found nothing. So the issue could have been boiled fluid but I hadn’t been using the brakes that hard prior to the problem. Or an internal failure of the master cylinder. Either way, the master cylinders can be a problem and with no solid evidence of any other cause I ordered a replacement brake master cylinder. I also ordered some Goodridge stainless steel brake hoses as this would be a perfect oportunity to replace the old rubber hoses.

I lack time to fully describe the job here but I think the pictures are the main help as a guide to the job of replacing the master cylinder here. I’ll upload some pictures of fitting the hoses in another post.

The brake and clutch use the same reservior, this hose feeds the clutch master cylinder and it split.

The hose that feeds the clutch master cylinder was split and I couldn’t get hold of a genuine replacement part at the time. I bought some of the correct type of hose from Merlin Motorsport (fuel or coolant hose is not ok to use) then cut and shaped it with the correct curve with the help of a little warmth. I’d read that some have had trouble using a straight hose to replace this curved hose and found it could straighten out again over time and end up with a kink in it. To help prevent this I added some heat shrink which I shrunk down with the hose in the correct shape. Years later the hose has remained in the same shape I fitted it.