T

Tmac

Active Member

• Jun 10, 2018

• #1

Hi all
I think I need to replace brake master cylinder on my Defender after changing front and rear brake pads the break pedal is going to the floor with hardly any breaking there’s no sign of leaks so I’ve been told the likely suspect is the MC as failed, question do I need to drain the brake fluid from the pipes all round before I take off the MC or can I drain after advice will be much appreciated.

 

Brown

Well-Known Member

Full Member

• Jun 10, 2018

• #2

Shouldn't be a problem whichever way you do it. If the original brake master cylinder is elderly it's a good idea to replace it as the seals have a limited life. The main thing I've found is that after you've had it apart. a lot of air can hide in the system and it'll take a while to bleed everything through. I'm very glad I have a pressure bleeder for times like this. Sometimes it helps to let it settle overnight and bleed it some more the following day.

 

T

Tmac

Active Member

• Jun 10, 2018

• #3

Thanks Brown, I’ve been told to just try bleeding the brakes before buying a MC.

 

jamesmartin

Well-Known Member

• Jun 10, 2018

• #4

if it splashes back in res when pedals pumped its a fair sign m/c is poor,if a system and m/c are empty it will often suck air back rather than drawing from res, you can use your finger over the outlets as one way valve to get fluid flowing before fitting pipes

 

T

Tmac

Active Member

• Jun 10, 2018

• #5

I’ve noticed jamesmartin after pumping the pedal the reservoir has more in than before I pumped the pedal is that an indication.

 

jamesmartin

Well-Known Member

• Jun 10, 2018

• #6

sounds like you need a new m/c

 

T

Tmac

Active Member

• Jun 10, 2018

• #7

Will have to order one
Thanks