Jump to content

Brakes not pressurising

Guest Phil Young

Recommended Posts

One of those problems again where there's probably going to be 10 answers telling me to bleed the system lol...

Ok so here's the deal - my motocross rear brake was working well, albeit a bit spongy, then it just stopped working.

I've spend god knows how long bleeding it, replaced the fluid, replaced the caliper and still doesn't work.

I've looked for damage to the seals of the MC and LOOKS fine. Fluid is getting to the caliper but doesn't want to pressurise.

If I take the line from the MC fluid will freely flow out.

If I take the banjo bolt off the caliper it stays put. If I press the brake lever down it will come out slightly but only a spit.

I've bled it with a hose as well and all that's come out was fluid... No air.

Help please :(

Link to comment
Share on other sites

Bleed the system :wink: but after you have either replaced the MC or the seals.

If you have replaced the fluid and the caliper it only leaves the MC. The seals may be passing so you can bleed fluid through but not fully pressurise the system to operate the pads against the disc.

Worth a shot.

Link to comment
Share on other sites

I would look at rebuilding the M/C

for it to work fine then to stop you have a problem somewhere

if you was just replacing fluid and had got air in then I would have said it would be trapped in the M/C

no leaking fluid anywhere?

Link to comment
Share on other sites

The m/c is dead as stu and jrh said, the spongy and then dead are the symptoms. Brake hose and caliper never give a spongy feel like the m/c will

Link to comment
Share on other sites

Ok in that case... Universal master cylinders for dirt bikes are only a fiver. Might have a bash at that next.

Definitely no leaks in fluid anywhere.

Edited by Anonymous
Link to comment
Share on other sites

When did you last change brake fluids?

and front master?

The question is...

When did the previous owner do it. I would imagine a long long time ago.

Link to comment
Share on other sites

Sounds like fluid going the wrong way.

Clamp off the pipe and squeeze the lever. If the lever can come back and no fluid squirtimg out, it's going through the bypass port.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Welcome to The Motorbike Forum.

    Sign in or register an account to join in.

  • Create New...

Important Information

Terms of Use Privacy Policy Guidelines We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Please Sign In or Sign Up