Brake pedal to the floor

[Lorin]

Just failed the MOT as the brake pedal goes to the floor To put it in context, when driving the brakes work fine. However, if you stop and then apply the brake peddle and press hard, the pedal creeps to the floor. If you give a pump it is immediately back up to the top but will again creep to the floor under sustained pressure. If the vehicle is moving, it does not noticably happen, as in the creep is so slow that I can slowly descend a big hill or brake slowly over a prolonged period of time (i.e. from 70mph) and there is no noticable creep. It is also not noticable if I hold the truck on the brakes on a hill. It is only when the pedal is pressed hard for quite a while.

Anyway it needs sorting. There are NO leaks anywhere. The hoses are all new and are braided, and the brake pipes are all fine. The system was fully flushed by Toyota about 5000 miles ago and was done properly - I watched so the fluid is all good. As you probably well know by now tinkering isn't a possibility for me Therefore, my only option is to take it to a mechanic with specific instructions on what I want doing.

Am I right in thinking the most likely fix is to replace the master cylinder with the only other possible culprit being the servo

 

[Lorin]

Re: Brake peddle to the floor

Pedal, I meant the brake pedal, and to think I hate poor spelling Why can't I edit

{Admin - "pedal" and other spelling mistakes corrected on your behalf }

 

[Chris]

Re: Brake peddle to the floor

That's pretty bad creep. Apparently all diesels do it. So I'm told. But not that badly. Unfortunately, one of the possible issues here, which I certainly experienced, is that the seals live out their happy little lives in a relatively short range of movement. They get all nice and cosy. Then someone pushes them right down the cylinder out of their comfort zone and they get all anxious and raggedy. When I looked inside my MC you could see where the seals had be living. One solution would be new seals and rebuild the old block. Or get a replacement from somewhere like Milner. I was lucky to get a genuine one from them . Nope it was the last one of the 4 hole.

Can't remember how much new seals were. You could perhaps turn them round? But as these are the things that prevent you from dying, I'd spend the money. Don't forget to bleed the MC though. Never heard of a servo going. They do seem to last a very long time.

Chris

 

[Lorin]

Re: Brake peddle to the floor

Cheers Chris, you're right it isn't worth messing around. I'll just grab a replacement from Milner and hope they're ok