Thought I'd sorted the brakes, new MC, sorted a remote reservoir, bled the brakes.

Good pedal feel, took the car out for a run and after about 15 miles the front's stopped working again! Last time I had this happen (previous thread) I stripped the MC down and the front piston seemed to have stuck in the 'off' position. Couldn't see a reason for this so cleaned it all and refitted it and it all seemd fine. But it obviously isn't

Went back to the car this morning to do some more jobs and the brakes seem fine again???

So what does the collective reckon it could be? I thought maybe something to do with the MC getting hot after a good run but I don't really know.

I have ordered another MC from a different supplier and a new reservoir but I am hoping it doesn't end up with the same issue!

Not happy though, this was going to be my first year at Stoneleigh in the Locost but it was not to be

Cheers.

JB

Are you using the Fiesta M/C? If so don't have a clue really, however, if it was me I would swop the brake lines over ie:front to back
and see if the front still locks off, that will tell you if the problem is in the M/C or the front brake lines/calipers.

Any old rubber flexis in the system?

I am using a Fiat 124 MC as recommended on here. The only flexis I have in the system are the 2 at the front calipers and they were bought new so I would be suprised if they are faulty.

I never thought about swapping the brake lines over, just assumed I would be looking at a MC fault.

Is your master cylinder able to move enough fluid? I don't know the style of your m/c but if your piston is bottoming out then your piston may not be moving back up the cylinder when you let the brakes off.
.......of course I may be talking bollox

Steve

The Fiat MC has a very similar setup to the Sierra one with 2 seperate pistons/chambers one behind the other. The main difference is that the Fiat one is striped down from a big nut fitted to the front whereas the Sierra one is stripped from the rear.

When the fault appears, it does feel like the rear piston is hitting a stop, which I am assuming is the front piston. It only happens after a longish run and after leaving overnight the fault seemed to go away.

I haven't taken it out again today, I will wait until I have swapped the lines over as suggested and then see what happens.

How about the adjustment on the rod. There should be a little wiggle when the brakes aren't depressed.

You're talking about a problem that occurs when your brakes are hot and your components have expanded further (and your fluid is hot)........assuming that you've got all of the air out of your fronts, is the m/c pushing enough fluid to move the caliper pistons as far as you need? Do you have any flex in the caliper or caliper mount - if the caliper is making the mount flex or is misaligned to your disc then you are losing a lot of braking effect.

Steve