T25 Brakes Problem

[HorTs]

Hey,

Apologies for my 1st post being a request for help.

We have a T25 whose brakes just don't want to work.

We've replaced the master cylinder and and all the other parts look fine. The sytem has been bled which improves the brakes but suddenly the brake pedal will have no resistance and will just drop to the floor when pressed.

Does anyone have any ideas?

Thanks in advance.

[sam_seed]

might be daft questions but we'll get them outta the way first:
you have got enough brake fluid in haven't you?
can you see any leaks anywhere?
you're 100% sure they're bled properly?

[HorTs]

might be daft questions but we'll get them outta the way first:
you have got enough brake fluid in haven't you?
can you see any leaks anywhere?
you're 100% sure they're bled properly?

No problem with the simple questions. Yes the fluid is at a good level and topped up after bleeding.

There doesn't appear to be any leaks and each corner has been been bled in turn.

[armyphil]

Sounds like you need to keep bleeding to be honest, you will still gave the old fluid within the pipes which can lead people to believe they are bleed, bit there may be air locks further back in the system don't forget the sequence is
furthest wheel away from master cyclinder moving progressivly closer to makd sure all the air is out

[paul66beetle]

Could be a problem with the replacement master cylinder? Was it new or refurbed? Has it been fitted correctly and push rod sitting in the right place?

I'd say if you were loosing pressure and the wheel cylinders and bleed nipples are all ok and you have no leaks it points back to the master cylinder not doing its job.

Are you using a powerflush to pressurise and bleed the system? If you are you could look at the pressure guage and see if you are loosing pressure out of the system.

[Aidan]

best quality master cylinder form Baxter or something cheaper ?

[HorTs]

Thanks for the suggestions.

We're not using a powerflush to bleed, that may be an idea though.

The MC is new not refurbed but was the cheapest from GSF, the reason we changed the MC was because of this problem, so we'd be unlucky if it was the MC.

Thanks again.