Mechanics

SAFARI BRAKE PEDAL FADE

1990 Nissan Patrol/Safari • 6 cylinder 4WD Manual • 400,000 miles

Hi, i've got a nissan safari 1990 that has a fading brake pedal when engine is running, so far the master cylinder has been replaced, new rotors all round, new pads, rekitted callipers and new pistons fitted, but still have a fading pedal, the callipers are all sliding freely, theres no leaks, and if I clamp all the brake lines at four corners it's fine, could the propotioning valve at the rear be causing this problem?As it's the only part thats not new, the indicator(!)Light flashes breifly as the pedal is initially depressed, any help greatly appreciated.
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Sonicone
April 1, 2011.




Can you explain your meaning of fading in more details? I need to verify that I understand the situation correctly.

KHLow2008
Apr 1, 2011.
Hiya, when holding pressure on the pedal while engine is running the pedal slowly drops to the floor, within about 10 seconds. Thank you for your reply.
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Tiny
Sonicone
Apr 2, 2011.
That is an indication of pressure leakage and it is due to either leaking or a bad master cylinder.

Check for leaks and if none found, check the master cylinder. The seals are leaking internally.

KHLow2008
Apr 2, 2011.

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