307 cc brake problem

[vw_99]

Afternoon.

2007 307 cc.
I stripped and cleaned back brakes due to a sticky pads. Now i have no brake pedal.
The pedal just goes to the floor and the brakes only just work when pedal is on the floor.
All slides are free and pistons pushed back easily.
There no loss of fluid and no visable leaks.

I have went round all corners and bled them but no air came out any of them.
I did for get to take cap of when pushing pistons back however.

I have read about "flipping" master cylinder seals.
But i have never come across this myself in 15 years.

Is flipping the seal a posibilty or am i missing something obvious.

I do get a pedal with pressure bleeder attached.

Thanks.

[vw_99]

All 4 flexis clamped still no pedal

[stevieturbo]

vw_99 said:

Afternoon.

2007 307 cc.
I stripped and cleaned back brakes due to a sticky pads. Now i have no brake pedal.
The pedal just goes to the floor and the brakes only just work when pedal is on the floor.
All slides are free and pistons pushed back easily.
There no loss of fluid and no visable leaks.

I have went round all corners and bled them but no air came out any of them.
I did for get to take cap of when pushing pistons back however.

I have read about "flipping" master cylinder seals.
But i have never come across this myself in 15 years.

Is flipping the seal a posibilty or am i missing something obvious.

I do get a pedal with pressure bleeder attached.

Thanks.

Perhaps an explanation of exactly what you did ?

[vw_99]

Sorry.

Both back wheels in air. Wheels off, slide bolts undone and calipers moved plenty life left on pads. Carriers off and cleaned, slides cleaned and regreased. Pistons pushed back easily.
All reaslembled with proper brake grease.

No visable damage to caliper piston boots or any leak from seals.

[E-bmw]

Is it possible that you have pushed the pads right back & they are now slowly being pushed back & have not yet reached the discs?

You did make sure that you did not let the fluid level drop off when bleeding so as not to allow air back in to the lines?

[vw_99]

Pads are touching disc and just working when pedal is on the floor.

Never let the fluid drop either.

[paintman]

You said earlier that you clamped all the flexis & still nothing.

Presumably with them clamped & engine off you pumped the pedal & still nothing?

Suggests to me a lot of air in the system, a leak somewhere or a faulty master cylinder.

[vw_99]

With engine off there is a pedal but not great.
As soon as engine on pedal goes to the floor.
You can pump pedal and it gets a little better but starts to drop straight away.

[paintman]

Sounds like the servo is OK which means the fault is somewhere else in the braking system.
https://autotechnician.co.uk/brake-servo-fault-fin...

Any chance of diagnostic to see if it shows anything up?

Might be an idea to ask on a Peugeot specific forum to see if they have any ideas e.g www.peugeotcentral.co.uk

Edited by paintman on Tuesday 30th November 13:38

[vw_99]

No codes stored anywhere.

No fluid in vacuum tube from servo

So either master cylinder or air i think.
But dont understand how air would have got in.

[stevieturbo]

vw_99 said:

Sorry.

Both back wheels in air. Wheels off, slide bolts undone and calipers moved plenty life left on pads. Carriers off and cleaned, slides cleaned and regreased. Pistons pushed back easily.
All reaslembled with proper brake grease.

No visable damage to caliper piston boots or any leak from seals.

So at no point was the hydraulic system interfered with or opened ? Very weird. If the system remained sealed, I do not see how air could ever get in.

And the pistons pushed back easily...these need wound back on handbrake calipers...I presume this is what you mean

[paintman]

vw_99 said:

No codes stored anywhere.

Checked with Peugeot Planet or A.N.Other code reader?

[vw_99]

Yea wound the pistons back easily with manually with tool.
Rubber boots on calipers still both intact and not split.

Dont understand how air could get in. Thats why im thinking master cylinder.

Only time bleed nipples were opened was after the problem started.

No access just now to plantet.

The only other thing i forgot about was it was valeted in between doing brakes and driving it.

Edited by vw_99 on Tuesday 30th November 18:51

[paintman]

Can't think of anything else to suggest.

Currently got one 307 1.6 petrol & my youngest had a 307 2 litre petrol.
Done brake work on both including pad & disc front & rear replacements & never had an issue.
That said, I've always clamped the flexi & opened the bleed nipple when retracting the caliper pistons so not pushing old fluid back through the system.
Whether that is of any relevance I have absolutely no idea.

[vw_99]

A few garages round about have mentioned "flipping" master cylinder seals but none have come across it before.
Its seem like it could be that. And when pressure bleeder is attached its forcing the seals to expand and seal.

[E-bmw]

Right, lets go back to basics as you don't really say enough detail for me.

You say you had no pedal & then bled the brakes, how EXACTLY did you bleed them?

You say that now when you pump the pedal the brakes work but only at the end of the pedal travel, with the pedal pumped & down try each wheel to see if the brakes are actually on & how hard are they on.

[vw_99]

Have very slight brakes on each corner when pedal right down.

Hose on bleed nipple into bottle of fluid.
Got somone to pump pedal while i opened nipple.
Held pedal down while i closed the nipple. Started at osr then nsr the osf then nsf.
No air came out of any off them.
I then repeated this with a pressure bleeder attached.

[E-bmw]

When you did bleed, did you bleed so as if to fully replace the fluid at each corner, or just a few pumps?

[GreenV8S]

It's hard to rule out mistakes not mentioned in what you've described, but assuming the maintenance and bleeding was all done properly then one possible cause is that you ripped the seal while bleeding the brakes. This can happen if the m/c is badly worn with a lip at the end of the normal range of travel of the pedal, and you then take the pedal past that point while bleeding. If you've bled the system thoroughly and can't get pressure with all lines clamped off then a failed m/c is really the only thing left.

[vw_99]

Just a dozen or so pumps at each corner.
Then went back round with the pressure bleeder.

M/c is the next step i think.