Brakes - master cylinder

[reptilechick]

Hello my trusty helpers.

Whilst on long trips my brakes seem to lose major pressure and therefore fail. After nearly rolling my MU and also cleanin up a roo, I am a little scared! Have worked out I can keep driving though to my destination if I keep tapping the brakes often to keep the pressure built up. Mechanic out here in Winton suggested that too as he has no parts to fix it.

My question to you guys is where can I find a new master cylinder? Can I use a rodeo one? Will it fit? Seems like my trip away may be a little longer. Had anyone else had this problem? Any advice?!!

[pig75]

I think a 3.1 jackaroo master cylinder might be a better fit as it has the same brakes as a MU

[Demonic]

Perhaps a new one wont be "that" expencive - famous last words.

[chrisfnq]

i have a spare one off my mu. thought I had a problem with it. changed it for a secondhand and brakes still the same. change my vacuum lines and improved greatly. happy to sell spare if you end up needing.. should be cheap to send.

[reptilechick]

Chris I will send u a PM when I get to Townsville, will see what is wrong with mine there and may be interested in yours!

[nig99]

If tapping the brakes keeps the pressure up, something must be knocking the pads away - I would be looking for slack wheel bearings or a warped or loose disk rotor.

When you say no brakes, is it a long pedal, or a hard pedal with no power? - first is what I suggested above and second is most likley a booster issue

[98Rodeo]

Im having a problem with mine aswell... the brakes 'work' if i just push on them once, but if i push twice the pedal is hard and there is very little braking power. Apart from changing the fluid what else should i check?

[geeves]

sound like a vaccume prob. If you hold the peddle on the second push do the breaks come back?

[reptilechick]

If tapping the brakes keeps the pressure up, something must be knocking the pads away - I would be looking for slack wheel bearings or a warped or loose disk rotor.

When you say no brakes, is it a long pedal, or a hard pedal with no power? - first is what I suggested above and second is most likley a booster issue

nig it seems to be worse on the dirt than on the bitumen. And if I use them regularly there isnt a problem. When it first happened, I pushed the pedal to the floor like it wasnt even connected, not hard at all, it wasnt until I pumped it 6 -10 times that I could feel the pressure starting to bulid up then my brakes worked. Long driving on the bitumen is fine, only driving on the dirt is when i happens, when things get shaken around a bit.

cheers all for ur help, would be lost without this forum!

[Yarno]

Front wheel bearings I would say, might just need a re grease and tighten, but more likely if it's been through water will need new bearings and seals...

[reptilechick]

Front wheel bearings I would say, might just need a re grease and tighten, but more likely if it's been through water will need new bearings and seals...

no water in alice springs! Front wheel bearings were repacked only bout 12months ago. Have it at Dad's now in Townsville so will work out what is worng, will pass on your suggestions! Thanx guys Chris I may be in touch if I need that master cylinder!

[MattMu]

As most have said it sounds like the pistons are being pushed back into the calipers for some reason. The most common are loose wheel bearings or warped rotors.
The hammering you get on dirt acentuates the problem additionally as you have said, the time between brake applications.

The more you use your brakes the more the pistons stay in adjustment and you dont have a problem.
After loong periods of not using your brakes or hammering offraod the pistons push back and it takes a few pumps of the pedal to bring them back into contact with you discs before you can grip them and slow down.

Goodluck anyway

Matt.