Lancia Motor Club

Model Technical and Interest => Fulvia => Topic started by: Michael Tryton on 09 July, 2019, 12:51:52 PM



Title: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 12:51:52 PM
Having consulted about this unfortunate condition on here, I decided a new seal kit was cheaper than buying a complete master cylinder, and eventually applied myself to these works.

Having read all the various threads on here about Fulvia brakes  but found, like The Curate's Egg, that they're only "good in parts...." and all a bit bitty (particularly in how vague some descriptions of crucial elements in these processes really were) I thought I'd take some photos to show this job as more of a continuum.

I've also tried to conflate lots of relevant snippets of various good people's wise advice, currently unfortunately lost amongst many threads or pages of chat, so they're useful to more folk than me.

How well I executed that process is a different question, but I believed it might help others in the same predicament as mine to see it done in photographic form, hence this new thread.

Like 'Game of Thrones' and all great epics, expect blood and tragedy in tantalising instalments, all following on shortly, and starting with what we started with:



Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:08:53 PM
The idea of photographing these components is of course to help ensure you reassemble and reinstall them correctly.

After jacking up the car on axle stands (with the back slightly higher than the front) I removed all four road wheels to give better access to the bleed nipples on the brake calipers.

The master cylinder and each caliper were each drained, before removing the master cylinder (M/C) from the servo unit by detaching the two brake line connectors and two 13mm nuts holding it onto the servo:  


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:13:37 PM
Uploading on here only seems to work one photo at a time, otherwise it times-out, so here's a few photos about this stage in the dismantling process, which speak for themselves:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:15:48 PM
Next, the M/C is removed from servo:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:16:57 PM
The servo, with domed nut of the operating rod which forces a larger piston into the master cylinder, visible in the centre:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:18:18 PM
And here's the M/C, with its protruding piston, released...


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:21:04 PM
And inspected before gradually being taken apart:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:22:20 PM
Here's the servo end of the M/C:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:23:15 PM
Thought it worth measuring piston extension 'as found' to replicate when reassembling:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:25:21 PM
Photographing internal components, so don't forget how they go back:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:26:03 PM
And again - these are the two upturned 'buckets' which sit in the first chamber:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:28:41 PM
You may be wondering why I put M/C back onto car at this point in proceedings - well, it was all about getting enough leverage on that monstrous 32mm nut at the end, the one with a big internal spring hidden behind it.

(It really didn't want to come undone....)


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:29:48 PM
And this what was left lurking inside after it had.....


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:31:48 PM
And, crucially, THIS IS WHAT YOU GET OUT.

SHOWN IN ORDER OF PARTS - brass-coloured piston at back being of course what goes into the servo unit.


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:33:46 PM
With the 32mm end-cap shown, it's crucial to replace the springs in their correct order - one is slightly shorter than the other:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:35:27 PM
And here's the servo end of things, again:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:36:06 PM
With its seals...


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:37:52 PM
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:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:39:38 PM
The vented metal spacer or valve, with its tiny holes to allow fluid to pass through under pressure.


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:40:45 PM
Everything must be scrupulously clean and smooth - free from corrosion:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:45:55 PM
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.
 


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:51:08 PM
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:


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 01:52:34 PM
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.


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 02:05:27 PM
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....



Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 02:08:48 PM
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.


Title: Re: News from the soggy pedal front
Post by: lancialulu on 09 July, 2019, 02:43:11 PM
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.


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 02:57:37 PM
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?



Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 09 July, 2019, 04:10:28 PM
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....)


Title: Re: News from the soggy pedal front
Post by: lancialulu on 09 July, 2019, 04:43:22 PM
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)?



Title: Re: News from the soggy pedal front
Post by: ColinMarr on 09 July, 2019, 07:59:47 PM
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 doesnít 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 


Title: Re: News from the soggy pedal front
Post by: Brian Long on 10 July, 2019, 05:28:54 AM
This all sounds very much like the problems that I had with my Flavia 2000 coupe's brakes. Over a period of time I finished up buying both a new booster and a new 'old-stock' (NOS) master cylinder in an effort to get a reasonably firm pedal. All to no avail, after a few applications the pedal would go to the floor.
It transpired that the master cylinder has an anodised bore. If not kept 'wet' in storage it will develop microscopic oxide blemishes which will destroy the rubber cups.
In my case there were incredibly fine score marks on the cups but enough to let fluid by and the pedal to sink to the floor.
The cure? Have the master cylinder resleeved in stainless steel. Several years later the brakes are still as good as ever although not rock-hard which I understand is typical of the Dunlop system.
P.s. Want to buy the shares that I have in a brake fluid manufacturing company?😊😊😊


Title: Re: News from the soggy pedal front
Post by: lancialulu on 10 July, 2019, 06:50:32 AM
Colinís point is a good one......

Re Dunlop braked cars being softish this is not my experience. My oem servoed system on my Flavia Vignale is rock solid pedal at the top as is my unservoed Fulvia 1.3 HF. Its all about getting the air out imho.


Title: Re: News from the soggy pedal front
Post by: fay66 on 10 July, 2019, 08:54:18 AM
Colinís point is a good one......

Re Dunlop braked cars being softish this is not my experience. My oem servoed system on my Flavia Vignale is rock solid pedal at the top as is my unservoed Fulvia 1.3 HF. Its all about getting the air out imho.
No soggy pedal in my 2c either with no servo.
Brian
8227   : 8)


Title: Re: News from the soggy pedal front
Post by: lancianut666 on 10 July, 2019, 11:40:29 AM
All sounds familiar to me I used a 5 litre container on my Flavia Coupe brakes... mind the hydraulic pressure jacked out the stainless steel liners in the wheel cylinders not helpful...the Appia ones are just as fiddly but practice makes perfect...
Clarkey


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 10 July, 2019, 04:02:14 PM
Well I've now had chance to act on Tim's latter suggestion to me, by disconnecting & blanking-off the manifold pipe.

I'd say the pedal DOES feel a bit harder, but it's still still rubbish. Although - as before & always - I've retained some vestigial braking effect through the front which, in combination with the handbrake, is enough to stop her rolling at low speeds.

Something else I think I can also feel is a sensation of each seal overcoming resistance as it is forced down the shaft - or is that just my paranoid imagining?

And I've also gained something else new: a hiss of air when I press the pedal down. A sinister development which (although I can't remember why exactly...) I do know, from reading on here, is one that should distress me even more - provides something else BAD to fret about? (Possibly involving a new life, to be spent in the front footwell?)

P.S. Yes, I did inspect the bore carefully and, yes, it did look OK but, hey, "microscopic scoring..."? Well, who can say? At least it's helpful to know that buying a new M/C is apparently a waste of time (and money too)......  


Title: Re: News from the soggy pedal front
Post by: fay66 on 10 July, 2019, 05:01:45 PM
Colinís point is a good one......

Re Dunlop braked cars being softish this is not my experience. My oem servoed system on my Flavia Vignale is rock solid pedal at the top as is my unservoed Fulvia 1.3 HF. Its all about getting the air out imho.
No soggy pedal in my 2c either with no servo.
Brian
8227   : 8)


Title: Re: News from the soggy pedal front
Post by: chriswgawne on 10 July, 2019, 05:22:21 PM
We have 2 S1 Fulvia Sedans with OE Dunlop brakes.
The GT brake pedal is solid with relatively short travel whilst the GTE with a remote servo has a longer pedal travel but still with a solid feel. The GTE has a front/ rear brake balancing valve with a nipple and this valve ( only fitted to GTEs) is tucked up above the central rear of the subframe. It's a devil to get all the air out and i have never understood why the remote servo doesn't have a bleed nipple on it.
Chris


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 10 July, 2019, 05:55:40 PM
Well my 1.3 coupe is - as all Series 2 are - equipped with a Girling system.

So am I to understand the panel's suggested solution to its current problem is retro-converting her system to a Dunlop one?


Title: Re: News from the soggy pedal front
Post by: Brian Long on 11 July, 2019, 04:56:17 AM
Regarding the hiss of air when depressing the pedal. That too was one of the problems that I encountered with the Flavia's brakes. Turned out to be a split diaphragm in the booster due to the car' s long period (17years) of being laid up.
In normal operation, the booster does exhaust a small amount of air into the cabin, there is a sponge rubber dust filter in there, but should be inaudible to all but the most acute of hearing.
To establish whether the booster is functioning as it should, after running the engine, turn off the ignition and pump the pedal. The pedal should move progressively higher over two or three strokes and also feel firmer. Leaving your foot lightly on the pedal and starting the car should result in the pedal 'sagging' sliightly.


Title: Re: News from the soggy pedal front
Post by: ColinMarr on 11 July, 2019, 07:00:39 AM
I donít think the soggy pedal has anything to do with the servo. Girling brakes are good and there is no point in considering converting to Dunlop. Donít give up!


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 11 July, 2019, 10:32:24 AM
Acting on Brian Long's advice, I reconnected the manifold pipe (also replacing a length of it prior to the inline valve, for good measure) and ran the engine to carry out the 'booster' test he describes above.
Then I pumped the pedal as Brian suggests. This established that the booster/servo element is working - it behaved as he said, though not so much in that 'pedal-sagging-when-you-rest-your-foot-on-it' bit.
With all that established, let's recap on the history of this incorrigible but characteristic Fulvia fault:
M/C professionally rebuilt by a garage, with a new seal set fitted about 5 years ago and, although described by them as "difficult to bleed", it has been fine until about a year ago, probably caused by a period of storage with little (not no) use.
M/C rebuilt again by me now, and I have to say the 'old' seals looked perfect with no marks or striations, which begs the question why they were no longer up to the job?
The bore of M/C had looked fine to me too, squinting down it, and I used a very small quantity of brake grease on reinserting pistons & seals so as not to scratch the precious cylinder-lining as they went in, as suggested in one of the posts/threads on here.
The car's whole system has then been bled to the point no air bubbles appear at any of the calipers.
Bleeding the M/C on a bench was a non-starter for me, as unable to do this without brake fluid spraying everywhere or any certainty it would stay airtight in the process anyway. However, thinking about where else could be left for air to lurk, the only place I can think of is the far end of the master cylinder, at that end-cavity sealed off by a very tight 32mm nut. Could an air pocket survive in there and cause these symptoms?
And wherever any surviving airlock might be, could a professional power-bleeding apparatus make any difference? (I've no access to a compressor).
Over to the Panel!


Title: Re: News from the soggy pedal front
Post by: lancialulu on 11 July, 2019, 11:50:30 AM
I think you may still be needing the reduce the pedal rod be c1mm. With the reservoir off you can examine carefully the feed holes. I actually opened one up (the rear one - without the pistons/seal in the body) with 1mm drill (as I was using silicone fluid and felt there was too much viscosity for the fluid to flow easily). In retrospect I think this was a wrong diagnosis and what I had done was effectively reduced the pedal rod. Anyway after that tweak the pedal returned immediately to the correct feel.

I still also think you need to bleed by the pedal and not pressure alone.....


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 11 July, 2019, 04:04:29 PM
Which is consistent with Colin Marr's grim observation:

"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 doesnít 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."

However, being protective of my upper spine, I wonder if maybe it's not the actual length of the pushrod that's wrong, just the M/C piston being sluggish in returning? Not as a product of any excess length of pushrod opposing it, but via some mechanical resistance in the bore? (It did feel a little like that even off the car, post rebuild, but I guessed that was probably just the new seals, keeping it tight by dragging a bit).

Anyway, lacking the appetite for 'Trial by Footwell' or intractable new obstacles bound to arise during its tortuous processes; let alone to incur so much pain while still achieving precisely nothing; I will instead call-on my glamorous assistant and go with Tim's less arduous bleeding-by-pedal suggestion.

So thanks for the continuing advice, gents, and I undertake to report back in due course:


Title: Re: News from the soggy pedal front
Post by: lancialulu on 11 July, 2019, 04:07:20 PM
Also Michael

A quick dodge for pedal adjustment is to slacken off the master cylinder from the servo and pack say a few penny washers in the gap and see if that makes any difference....

Tim


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 13 July, 2019, 07:40:47 PM
I did like Tim's bit of lateral thinking about achieving change in the push-rod length by adding some 'penny' washers, instead of grovelling in the footwell; so disconnected my M/C from the booster-cum-servo again so that I could insert some; prior to excecuting that traditional two-person bleeding exercise which he'd also recommended.

What this preamble revealed is how the M/C brass piston doesn't seem to move outwards from the M/C housing like you think it might, once released from the pushrod. It has stayed short and immobile - as photos.

Is this how it should behave? Because if it is dragging and loath to expel itself from the M/C housing, could this be the root of the problem?

Over to the Panel again!


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 13 July, 2019, 07:41:35 PM
2nd photo of the reluctant piston:


Title: Re: News from the soggy pedal front
Post by: lancialulu on 13 July, 2019, 09:27:52 PM
Not sure if this is relevant? My Flavia this year developed something similar in that the brake pedal would go down c1/3 before activating the rod (then the brake would work with a firm pedal). I deduced that the rear piston had got stuck for some reason someway down the bore. Now on the Flavia the is a rear and front priming pump in the reservoir. Out of curiosity more than any thing I gave the rear plunger a push and it went somewhat then after it had returned it would not push down anymore (ie the MC had fully primed). Now I had a firm pedal right at the top where I remember it had been normally. After several weeks of use it has stayed in the normal position. Odd....


Title: Re: News from the soggy pedal front
Post by: ColinMarr on 14 July, 2019, 08:08:24 AM
I think you have identified the problem! As you say, the piston is not fully retracting, either because it is jammed or the return spring(s) have failed Ė hence no pumping action. Sorry, but I guess you have to dismantle it and start again. If there are any deficiencies in the m/c body itself, I happen to have a good re-usable one.


Title: Re: News from the soggy pedal front
Post by: lancialulu on 14 July, 2019, 09:00:17 AM
As Colin says this is the problem. It may be a hydraulic lock in the incorrect assembly of the one way valve at the front of plunger 2 (see attached).

BTW not all seal kits come with 4 u seals. Most come with 3 u's and an o ring. I cannot remember if the o ring replaces the rear seal or more likely the middle seal... Maybe someone can remember?


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 15 July, 2019, 03:16:11 PM
Well, I've taken M/C off again and found that, yes, even after draining the unit, the 1st piston after the servo is absolutely stuck; so am giving up and sending it off to Past Parts, who are familiar with this type. Let's see what they make of it.

What I'm calling the 2nd piston is the one at front of the car and furthermost from the servo and that was still fine, completely free; as of course they both were initially, after my rebuild & reinstallation.

Thanks for the attached pdf - that's the same diagram from the workshop manual which I was working to when fitting the new seals to each piston, although poor print quality makes orientation of some seals passing ambiguous.... This and the choice of which seals to use from the kit has been discussed on here before - the rearmost one on the 2nd piston can either be a 'top hat' shape like all the others, or replaced with an 'o' ring, which is what I did. The 1st piston, which is stuck, was all 'top hat'.


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 07 August, 2019, 08:38:41 AM
My master cylinder came back pretty promptly from PastParts, with its piston unseized and their invoice duly endorsed:

"M/CYL SLEEVED 80.00. LANCIA MASTER CYLINDER REBUILT USING SLEEVE KIT SUPPLIED BY CUSTOMER. THIS UNIT CANNOT BE SLEEVED AS IT IS NOT A STANDARD BORE SIZE. WE HAVE HONED THE BORE WHICH IS NOT IN THE BEST CONDITION AS BEST WE CAN".

They also did me the courtesy of phoning me just before sending it back. Confirming that they had done this type of Lancia master cylinder before, but they held no dedicated sleeves in the right size (is it 28mm for a 21mm cylinder like this?) to mirror the curious interrupted passageway which you can see inside this master cylinder, which presumably requires three sleeves in a row.

The cost as billed to me was £80 plus £8.75 Fedex delivery; plus 20% VAT; making a total price of £106.50.

I refitted the cylinder on the afternoon of receipt and, after another quick bleed all round the following day once the fluids had settled, I drove off - job done! While the lorry that suddenly stopped dead in front of me necessitating an emergency stop gave proof that things were indeed now right.

Perfection is rare in this life however, and after successfully being assembled, disassembled, then reassembled over and over in the course of this labour, the lingering fly in my ointment now is the rearmost supply pipe to the master cylinder which now constantly seeps fluid. (See picture). I've taken it off again, added a new copper washer/then another copper washer, gradually made it tighter AND TIGHTER, but still it leaks....

Having repeatedly tried but failed, I've run out of fresh ideas (plumber's tape?) and throw this latest niggle over to the Panel. Suggestions?



Title: Re: News from the soggy pedal front
Post by: lancialulu on 07 August, 2019, 08:52:26 AM
try to anneal the copper washers. Heat up to cherry red and let cool down. Works for me.


Title: Re: News from the soggy pedal front
Post by: rogerelias on 07 August, 2019, 09:40:03 PM
not sure if it's my eyes.But looking at the picture is there a copper washer missing between the cylinder and the union, can see on the front one but not on rear one, but it could be my eyes  :o


Title: Re: News from the soggy pedal front
Post by: ColinMarr on 08 August, 2019, 08:17:56 AM
I find it curious that they expected to sleeve it, but couldnít and then simply honed the bores. I hope that is adequate treatment. Do you know how badly pitted the bores were in the first place?


Title: Re: News from the soggy pedal front
Post by: chriswgawne on 08 August, 2019, 08:41:14 AM
My experience of OE (Sabif?) Fulvia S1 and S2 and Aurelia aluminium master brake cylinders is that to work properly, the bore needs to be very highly polished with honing not being smooth enough. And I assume they used aluminium because a steel one couldn't be polished highly enough?

Discussing this with Omicron a few years ago,  if one gives one to Omicron to refurbish (which I have actually never done) , they regard the highly polished inner bore as being critical. They also have the facility to bench test under pressure.
I understand this need for the highly polished finish is to ensure the seal carrier ( Aurelias have one, Fulvias have two as dual circuit)  returns correctly to rest so not only do you get a firm pedal but also in the case of Fulvias the inner seal carrier returns to the correct position using the different rated springs either side of it.
In both cases, if this doesn't happen, one gets ever reducing pedal travel with the brakes ( front in the case of Fulvia I recall) locking on in the end.

Just recently, I tried a visually perfect Fulvia master brake cylinder which I have fitted twice with new seals and each time the brakes have locked on in the end.
Chris


Title: Re: News from the soggy pedal front
Post by: Scott on 08 August, 2019, 04:12:38 PM
I can see from this topic that my related topic of a couple of years ago (http://www.lancia.myzen.co.uk/forum/index.php?topic=9756.0 (http://www.lancia.myzen.co.uk/forum/index.php?topic=9756.0)) has already been spotted/cited.

I can confirm in this instance that after problems with my own master cylinder I sent a replacement (kindly located for me by this forum) to PastParts for checking and restoration. Having had a chat with them at this time they confirmed they would need to hone and sleeve and indeed I have just gone and dug out the invoice I received and it specifically says "...sleeved and assembled by us with new seal kit.
This does seem to be at odds with the wording on your invoice Michael so I'm not sure what's going on.  [I note that you supplied a 'sleeve kit' with the item - did you get this back?!].

Whatever PastParts did to mine seems to have worked well as, for anyone who read a short article I wrote in August 2018's Viva Lancia!, I then did a 3,390 mile trip around Europe including lots of braking action coming down various Swiss mountain passes!

As to your leaking; I've taken a close up of my connections for comparison. As well as Roger's observation could an alternative be that your new washers are actually slightly too thick? Could this be preventing the connector seating properly?




Title: Re: News from the soggy pedal front
Post by: ColinMarr on 31 August, 2019, 07:41:04 PM
I had hoped this thread would have continued a bit longer, if only to resolve the differences between sleeved, honed and polished bores. Has anyone had real experience of having a Fulvia master-cylinder re-sleeved successfully with a steel tube liner? And if so, what was the interior finish of the steel bores?

Colin


Title: Re: News from the soggy pedal front
Post by: Michael Tryton on 02 September, 2019, 08:01:29 AM
I'll certainly be updating this thread shortly, once my other commitments allow me more time.

Had also noticed some ambiguities in parts-terminology seem to have crept in, which won't help the narrative, so will happily respond to those from my point of view - once I get time to sort that lingering leak around the brake pipe unions, and report back to The Panel.

(Hold The Front Page!)


Title: Re: News from the soggy pedal front
Post by: chriswgawne on 02 September, 2019, 08:23:56 AM
Like Colin, I am interested to understand exactly what is and isn't possible as rhd OE Fulvia S1 brake master cylinders aren't available. I know alternative master cylinders can be fitted but if possible I want to stay with the original part and appearance.
Chris


Title: Re: News from the soggy pedal front
Post by: Jaydub on 02 September, 2019, 04:05:21 PM
Just a thought Michael, are the faces on the 2 way block absolutely flat/parallel and the inside diameter of the washers a snug fit on the banjo bolt, as that could be the source of the leak? If the bolt has been over tightened and the block faces have dished inwards (concaved) the washers may not seal.