Hi Guys.

Yesterday I was out in my "04 115JTD towing a trailer with a bike on the back and all was fine. This morning, I drive to the end of the road and the brake pedal nearly hits the floor. It comes up a bit by pumping it, but still goes down slowly under a constant pressure. Even pumping it up results in very little slowing down, in fact it feels like it is getting weaker the more pumping I do.

I have had the wheels off and checked the pads and rear shoes. All are OK and no sign of leaks or failure. The brake hoses are fine and there is no sign of brake fluid leaking anywhere, and the reservoir is still up at the normal level. I clamped off the front brake hoses and again there was no difference.

Can anyone suggest what to check next please? I suspect it might be the brake master cylinder, but it seems strange that it was working fine yesterday and so bad today. I am reluctant to replace the master cylinder without further checks due to the time, cost, and strain on my knackered back, especially if it turns out to be something else entirely.

Any ideas or advice would be appreciated.

Thanks.

Hi.check if there is any leakage on your hydrolics on the clutch,if it sucks air there the brakes and clutch working on the same resivoir will give you a serious headache.you will need to bleed to whole system.hope it helps.

Thanks for that thought. As the fluid reservoir has not gone down at all, I don't think it is the clutch, but I will bleed it anyway, if I could only find the clutch slave cylinder! I assume it is under the air filter, so will have a look tomorrow.

I was away over the weekend, so haven't looked at it until today. I have now replaced both rear brake slave cylinders and brake shoes and bled them. Still the same as before. Oh, bother! Or something like that, is what I thought.

I have managed to find the servo unit (searched behind the engine with a torch, and there it was!), and there are no obvious leaks from there either.

I will have another look tomorrow when I can stand up straight again (thirty years of being a plant mechanic have ruined my back).