News from the soggy pedal front

[Michael Tryton]

And here's the servo end of things, again:

[Michael Tryton]

With its seals...

[Michael Tryton]

The first piston (those 2 black 'bands' being what you replace from the seals kit) - which does of course reside nearest to the servo end:

[Michael Tryton]

The vented metal spacer or valve, with its tiny holes to allow fluid to pass through under pressure.

[Michael Tryton]

Everything must be scrupulously clean and smooth - free from corrosion:

[Michael Tryton]

With the internal pistons cleaned, the internal bore of the cylinder itself checked for any significant signs of wear (there really weren't any!) and new seals refitted according to advice & diagrams of their correct positioning found at:

http://www.lancia.myzen.co.uk/forum/index.php?topic=9756.15. (the most useful discussion on here, probably...?)

....it was time to replace the M/C in the system.
 

[Michael Tryton]

Of course, Gunson's 'Eeezybleed' is a handy aid for the solo mechanic, but for Lancia's maddening decision to design the M/C cap on their Fulvias to fit with all the precision and tightness of a rat-catcher's cloth cap, making 'Eeezybleed's apparently unusable.

And requiring some ingenious people on here to come up with various different solutions to keeping an airtight seal on the Fulvia's M/C, while solo-bleeding with an 'Eezybleed' fed by 10psi (max.) in air pressure courtesy of a handy spare wheel:

[Michael Tryton]

The advised order of bleed nipples for the bleeding sequence is (it says on here):

2x FRONT UPPERS (LH then RH, or vice versa, apparently it doesn't matter which side first)
2x FRONT LOWERS (as above)
2x REARS.

Also important is keeping the 'Eeezybleed' reservoir nice and high.

[Michael Tryton]

So there you have it - all carefully restored to be just as it was.

Each of the four calipers successfully 'Eeezybled'-through, with not a bubble left in sight.

Of course it is the M/C master cylinder (now complete with a nice new set of seals) which has been the focus of all this attention: conscientiously rebuilt, reinstalled; then pedal-pumped & bled-through too; as it has been.

Only a shame that it looks exactly the same, externally, as it did on my starting out on this project....

[Michael Tryton]

And even more of a shame that - with wheels refitted and the car back on its wheels - its brake pedal is exactly the same.

Foot to the floor.

[lancialulu]

Did you put the set screws back in to restrict the pistons?

Did you clean out the little one way valves behind the circlips?? And assemble correctly (cant see from your photos)?

Did you check that you could push fluid through with the pedal (needs 2 people)? My experience is that these master cylinders dont always fully prime and while fluid flows through them they need a non rapid pedal action to get the fluid everywhere into the MC.

[Michael Tryton]

Yes, thanks for these suggestions, Tim, I did reinstall the 2 set screws - and I should have mentioned there were some helpful marks present on the floor of the M/C reservoir to align their slots with.

And, yes, I cleaned the holes in the valves out with a pin.

Which only leaves your last paragraph. I did sort of operate the pedal (alone) at various points - but to be honest there didn't seem any way of knowing what's going on inside that blooming M/C, even when I did. (And my tame pedal-presser is a busy lady, not always available).

Though if air pressure applied through its cap at the front of the car is good enough to cause fluid to flow on a caliper located right at the back of the car, then perhaps I'd complacently assumed that this fluid was successfully getting through all the M/C's various chambers first: that all was good?

Though I read last your point as suggesting that fluid still isn't necessarily reaching some of the deeper nooks & crannies to be found within a Fulvia's M/C?

If it's not, what next?

[Michael Tryton]

And having been out to look at her again, here's another thing:

Engine off, slowly depress pedal and you get some feel/resistance.

Run the engine and it's gone all lumpy, while the pedal flops to floor with no resistance whatsoever; but doing so seems to upset tick-over even more.

Servo to manifold pipe? (I've checked that....)

[lancialulu]

BTW did you examine the MC for scoring and pitting or was it nice and smooth all over...And did the old seals look damaged and in need of replacement?

The marks in the base of the MC for the set screws are in fact the original clench marks to stop the screws undoing....

The tickover goes lumpy as you are demanding vacuum for the servo and this is due to the pedal going to the floor not the otherway round. Take and block the servo pipe. If the MC is working you will have a hard pedal.

Do you have any braking of the front calipers (the single circuit to the bigger pistons in that caliper)?

[ColinMarr]

Some of this description is horribly familiar! Although you measured the distance between the projecting rear end of the m/c and the servo it may be that the length of the push-rod between the pedal and the servo is not allowing the m/c piston to retract beyond the fluid feed hole, so that it doesn’t pump. It is a pain in the neck to do it (literally!) but you could try adjusting the length of the push rod by shortening it a few turns, which should allow the piston to come back a mm or two.

As you probably know, access to the push rod is through the footwell and working upside down to get the split pin out, retract the plug, take the rod off the ball on the pedal and working blind with a 17mm open ended spanner on the lock-nut and an 11mm spanner on the flats. Such fun!

Colin