brake prob pissing me off.

[EldarO]

car in question is an LN85 hilux.

changed the front pads, bled the calipers.

problem is, you need 4 or 5 pumps to come to a stop while driving.

fair enough, i thought i might need to bleed it more, so i did, nothing much came out but fluid.

normally id assume its just air in the lines, but the thing that puzzles me is that the "brake" light is on while the car is on, leading me to beleive the fluid is low.

but it isnt.

anyone have any idea what the hell is up? need the car for work tomorrow morning

im assuming i might need to bleed the master cylinder itself!??!?

[Billzilla]

Try bleeding the system with the engine running.
On rare occsionals it'll help get more air out of the system.

[EldarO]

so why does it take so much pumping then?

the brake isnt spongy...

its the same feeling as you pump the pedal with the motor off, excatly the same, it gets harder and harder.

although if you leave it after that, it gets piss weak again.

do i need some special pressure bleeding tool thingy? (talking out of my ass here, never even heard if one of the things exists)

[Dieseltrain]

Maybe youve torn the diaphram in the master cylinder?

[EldarO]

nah, havent, brakes were fine prior to bleeding, the pads were just low.

cant see how i couldve torn it, but is there anyway to check?

the weirdest thing is the damn brake light, why the fudge is it on?!??!

[Wildsupra]

when pushing the piston back into the caliper it may have disturbed the seals in the master cylinder as the pressure was forced backwards through the master cylinder.

Fark knows how ya would check with out dismantling and re assembling the master cylinder though?!?!
If you can pump it up then hold it and it slowly goes to the floor while ya holding it down i'd say a leaking seal in master cylinder.

[EldarO]

well, it doesnt, it holds solid.

but if you let it off, and drive around again, it goes soft.

as you can tell, its fucking pissing me off.

dog shit fucking car.

[EldarO]

hold up, that couldnt happen matty.

in order to get the caliper off, i had to completely remove the line from the caliper, and i pulled it out of the car.

i pushed the piston back, fitted the new pads and slid it all back on.

at no point did it ever push fluid back, and this is why i paid extra attention (about 25 minutes per side) bleeding it.

[Wildsupra]

hmm ok then, must be air in the line then, could be the rears with air in em depending on how the proportioning valve splits the pressure up, try bleeding the rears aswell

[EldarO]

well the master is partioned off, so much so that i didnt touch the rear section.

went over to mikes place and bled them a bit more.

on the way there i noticed the brakes worked better, and we bled em out and now they can lock the fronts up at about 90% pressure.

still not ideal though, so ill take it in to have it checked tomorrow.

i might bodge some stuff up, but i dont fuck with brakes.

cheers all.

[EldarO]

oh, and the "Brake" light disappeared after we bled it again (another 10 mins per side)

[Wildsupra]

i'd still bleed the rears anyway to be sure....

[IN 05 NT]

GRAVITY blled them, undo the bleeder and let it drip out slowly. one at a time,

[GT1978]

Yeah I'd definately bleed the rears also. Is the brake warning light sensor on the proportioning valve of the hilux. If so I would think air could have been transfered between the front and rear circuits at this point.

[twentyEight]

well, it doesnt, it holds solid.

but if you let it off, and drive around again, it goes soft.

Then it doesn't hold solid...

Re-bleed the system, and start from the furthest point away from the master... (ie. rear-left, then rear-right, front-left, front right)

Chances are, in the process of bleeding the system, your MC has blown a seal that was probably very close to dying anyway... But, re-bleed the system properly to narrow down the problem.