Brake Bleeding

[stew205 17]

I am having a nighmare today, one problem after another

 

 

I have just fitted 4pots a 406M/C all new brake lines and new disks and pads at the back.

 

Anyway, I'm at the stage of bleeding the system. Or be it I was at the same stage about 3hours ago!

 

 

The 4pots have 2 nipples per caliper I have been opening the furthest first then nearer or the two to the M/C second. Is this correct or should I have them both open at the same time??

 

This is the sequence I bleed the car in. I have a front and back split system.

 

N/S/R

O/S/R

N/S/F

O/S/F

 

 

Usually on the closing the final brake nipple the pedal goes hard but even though it seems I have expelled all the air the pedel is still soft. The pedal doesn't rise quickly either, alot slower than it should.

 

I don't have the vacumn for the servo connected either should I block this???

 

 

Does this sound like a leak??? Or though I have checked all the connections and all seems well.

 

Could it be a knackered servo???

 

 

I really hope somebody can help me out as I was planning to have this all done today.

 

 

Thanks

Stew

[C_W 3 1 Cars]

I don't think the sequence makes an difference tbh.

 

By not having the servo connected this won't affect the pedal feel with the engine off, it should be firmer without the engine running anyway.

 

I use an eazibleed now which uses a tyre (inflated to 20-25psi) which pushes the fluid from the reservoir through the whole system under pressure.

 

One thing that sometimes happens is that the pedal pressure/feel can "come back" after the brakes have bedded in and settled down.

[stew205 17]

Any idea why the pedal doesn't return properly Chris???

 

 

Stew

[C_W 3 1 Cars]

You mean it feels almost "sticky"? When I changed my m/c it felt like that but was perfectly normal once being used.

[taylorspug 7]

My vento had 4 pot AP's on it and these were the same, the pedal always felt bloody awful and was reluctant to return, but it was fine once you got it running and the brakes warmed up.

 

Dan.

[stew205 17]

To say the least "it feels all most sticky"

 

Its not notchy when it returns but it is VERY slow in coming back.

It also concerns how easily the pedal drops to to the floor, its as though I have a leak but have check several times and found nothing.

 

 

I'm going to try and re-bleed tomorrow and see how things go.

 

 

Thanks for the replys though its always good to hear other peoples experiences.

 

 

Stew

[C_W 3 1 Cars]

I would check everything for leaks etc and do a quick bleed. Then, making sure the brakes actually stop the car, take it for a test drive and then try and bed the brakes in. Even the slightest amount of the pad having to move to sit squarely on the disc can account for a fair distance in pedal travel.

[stew205 17]

Update

 

 

This morning I have checked and nipped up all the connections.

 

Re-bled all the calipers.

 

 

The pedal seems to return normally (may have been a small leak?).

 

But still the pedal drops to the floor with minimal resistance.

 

 

When somebody presses the pedal the rear discs can't be turned by hand but the fronts can. Can this still be put down to bedding in??? I would have thought there wouldhave been enough braking force to stop them from turning??

 

 

I'm now concerned that I have the wrong master cylinder.

 

I bought it from a motor factors under the impression it was a pre98 non abs 23.8 pug 405 M/C.

 

It does not have 23.8 stamped on it and it isn't pysically any bigger than the standard one. The only thing which seems different is the ports nearest the front of the car seem to be a bit closer to the end of the M/C. THis may genable it to have its extra travell.

 

Would a standard M/c create the symptoms I'm having????

 

 

 

Help

Stew

[C_W 3 1 Cars]

Even a standard master cylinder will work with calipers needed (in theory) a larger m/c so I don't think that would be the problem (irrespective of whether it is a bigger or standard m/c you have). If, when the pedal is pressed to the floor you can still turn the front discs/wheels then the brakes don't work AT ALL and that's not a bedding in problem.

 

Not sure what's going on I'm afraid.

[les3002 0]

my 406 23.8mm master cylinder is physically bigger than std so i think they have gave you the wrong one although as said that wont give the affect your describing

 

i would get an easy bleed and do both nipples at the same time on the fronts see if that sorts it

[stew205 17]

SCHOOL BOY ERROR ON MY PART

 

 

 

In my rush to fit the 4pots on friday night had fitted the N/S caliper to the O/S and vice versa!

 

Meaning the bleed nipples were facing down and causing an air lock at the top of the caliper

 

It only click when I was at work today.

 

 

 

Changed them over and re-bled this evening. I now have a good firm pedal.

 

Still can't test them properly till the engine is in and running (maybe this weekend, fingers crossed).

 

 

Thanks for the advice any way

 

Stew

[les3002 0]

lol nice one mate, at least you got it sorted!