bleeding brakes!!!!

[jord294]

hi guys

i have been doing part restoration on my '91 405 mi16 2wd and have a problem

before stripping the car down it drove perfectly, and brakes were spot on.

i have replaced [u]all[/u] brakelines, calipers and fitted a new load valve to rear axle

after a while i seemed to have bled all air out of the system. pedal has excellent pressure

but when i start the car, the pedal goes soft, but not straight to the floor.

do you think i still have air in the system?

thanks

[jord294]

thanks

i used a one man bleeder, but think i'll invest in a pressure bleeder.

also found out that i need to position the rear caliper so the nipple points upwards, to expel all air.

[jord294]

Locknut said:

I don't understand this. The bleed nipple should always be at the top. Have you accidently swapped the callipers left/right? Swapping would cause the nipples to be turned down. You will never bleed the callipers properly unless the nipples are at the top.

no, i haven't accidently swapped the calipers. the bleed nipple is at the top on the side



but according to the haynes manual and advice from a peugeot forum, when replacing rear calipers, the caliper must be bled with nipple pointing up and a piece of would wedged so piston doesn't pop out.

will give it a go over the weekend, and update

[jord294]

Old Merc said:

I often had problems bleeding the rear calipers on 405`s.I would unbolt the caliper,balance it on top of the disc with the nipple up,move the piston back with a wind-back tool and then bleed it keeping the wind-back tool in place.

that's how i'll be doing it.

that'll teach me for fitting shiny new parts to another peugeot. said i wouldn't do another resto after doing my 309 gti

[jord294]

this is the alloy block, and sounds sweet as

i also have a set of 405 T16 alloys that will go on the car after winter.

got a gunson pressure type brake bleeder now, so will let you know how i get on

[jord294]

Old Merc said:

I often had problems bleeding the rear calipers on 405`s.I would unbolt the caliper,balance it on top of the disc with the nipple up,move the piston back with a wind-back tool and then bleed it keeping the wind-back tool in place.

this is how i did it, but sadly i still have a bit of pedal travel when the car is running it doesn't go to the floor and the car brakes evenly

i have a super solid pedal when car is switched off though

i was told that maybe there could still be air in the system, but can't seem to get anymore out. even with car running and not

perhaps my abs pump is worn?? i have a spare one i could try. i also have a spare new m/c

is it possible air could be trapped via the brake pressure regulator?

should i try a pressure bleeder?

it's the only issue i have now, as it would of passed it's m.o.t yesterday if pedal had of been stiffer

[jord294]

small update

have since learnt that the abs pump on the car wasn't working.

i have replaced the unit, and now i can hear the pump when i switch the ignition on

will be back to report when i bleed the system again

[jord294]

PESKY M/C !!! must of been internally leaking

genuine new m/c now fitted, and brakes bled (even ran car in gear on axle stands and dabbed brakes, just to make sure there wasn't a spongy pedal)

turns out, i had bled brake system properly initially, but dodgy m/c gave the feeling there was still air in system.

in for m.o.t this week, and am confident it will pass