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Discussion Starter #1
was driving to kimmeridge today with the GF, goin down a hill when i put my foot on the brake and it hit the floor with no pressure and the actual brakes binded a tiny bit, pumped the peddle like crazy then it worked again, needless to say a part of my body twitched like mad!! so i decided to get the van home but every so often it would happen again, peddle goes all the way to the floor. have checked the fluid, level hasnt changed.

please can anyone tell what part is faulty!? servo...master cylinder...vacuum hose..? i have no idea!! any help would be much appreciated!!

1995 (N reg)
1.9D T4
 

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I have the same problem just now, think mine is the servo after changing the master cylinder, have you checked that the vacume pump is OK by pulling off a hose on the servo and seeing if it sucks at your finger?

:confused:
 

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i would deffo be looking at the master cylinder sounds to me like your seals have gone .. have you checked for any leaks under the van ?? pump the brakes a few times then move the van and see if you can see a puddle
 

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Discussion Starter #5
yea have checked under the van, cant see any leaks, the van had been sat there for bout 12 months before i bought it so would explain why seals have gone, not getting used/lubed. havent checked the vacuum hose yet for suction tho. but think it sounds like MC tho like you said. cheers guys!! will update this thread when i have got MC changed.

thanks again
 

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Assuming you've checked the obvious that the brake fluid level is correct and there are no obvious leaks...

Master cylinder seals. Replace the master cylinder - don't get a master cylinder seals repair kit.

Brake hydraulics work at quite high pressures. What's happening is the lips of the seals have worn too much and now when you press on the pedal, the fluid just wooshes past the seals - because of the pressure, only a tiny leak past the seals is necessary. You won't see any external fluid leakage either, as the fluid is still inside the system, just not getting pressurised.

A possible cause is the 12months the van stood, the brake fluid has slowly absorbed moisture from the air - which slowly corrodes the inside of the master cylinder. Only the tiniest amount of corrosion is necessary to cause wear on the master cylinder seals as they slide over that tiny rust patch - and can lead to sudden failure. That's why replacing the seals doesn't work for long - the root cause hasn't been fixed.
 

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Discussion Starter #7
right then guys... here's the update, spoke to a mechanic mate and he said if i push the pedal down very slowly and it hits the floor then its the MC, pushin the pedal slowly will allow the fluid to pass the damaged seals. i did that and the pedal did hit the floor.
went to GSF and got a brand new master cylinder this morn, cost £80 but worth knowing that its spanking new. like rubberbiker said, i didnt wanna get seal kit cos it'll only happen again 12 months down the line due to rust inside. replaced it this morning, bled the brakes but didnt have to bleed the clutch, took her for a spin, job done!! :) no more problems!! cheers fellas!!
 

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right then guys... here's the update, spoke to a mechanic mate and he said if i push the pedal down very slowly and it hits the floor then its the MC, pushin the pedal slowly will allow the fluid to pass the damaged seals. i did that and the pedal did hit the floor.
went to GSF and got a brand new master cylinder this morn, cost £80 but worth knowing that its spanking new. like rubberbiker said, i didnt wanna get seal kit cos it'll only happen again 12 months down the line due to rust inside. replaced it this morning, bled the brakes but didnt have to bleed the clutch, took her for a spin, job done!! :) no more problems!! cheers fellas!!
Good news fella
 
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