Lancia Motor Club

Model Technical and Interest => Fulvia => Topic started by: Scarpia on 26 September, 2007, 07:12:11 AM



Title: Brake bleeding fulvias
Post by: Scarpia on 26 September, 2007, 07:12:11 AM
Anyone any useful tips for this job. I have done it many times over the years and never yet done it with any ease or great success.Is it just me or is it more difficult on a fulvia than other cars?
In this case its a series 2, 1.3s with dual circuit .
I also have a one way "bleeding" kit.
The order I use is top front nipples; bottom front; and then the rear. This is in fact contrary to the general advise of furthest away first but that also wasn't very successful either.Also, once air gets into the master cylinder after a completely dry system, how do you get fluid to pump through at all? I had a devil of a job to get any action as a consequence of pumping the pedal whilst bleeding last time I rebuilt the brakes.I"ll be facing the same problem soon I suspect.I can rebuild an engine but I always struggle with brake bleeding on cars.!Should I see a therapist or am I just mechanically inadequate....?


Title: Re: Brake bleeding fulvias
Post by: stanley sweet on 26 September, 2007, 11:02:09 AM
Had the same problem on mine a couple of years back after rebuilding the master cylinder. I was pumping the pedal as my friend went around bleeding them as on a normal car. There was no pressure building at all and eventually I saw brake fluid running down the bulkhead. I had a look at a Lancia site and discovered the fronts have to be bled first, then the backs. Back in the workshop the following evening I told Graham what I'd discovered and he'd also found that the master cylinder has to be rebuilt 'wet'. Did that, bled the front first and the rears last and everything went perfectly. Have you someone to help you? Makes it much easier. It sounds like you've been doing it right anyway so I'm not sure what else you can do. Think I found the answer on the Viva lancia site in the Q and A's.


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 26 September, 2007, 11:44:09 AM
Quote
Back in the workshop the following evening I told Graham what I'd discovered and he'd also found that the master cylinder has to be rebuilt 'wet'.

I always end up immersed in brake fluid when I perform this job.Does that count as a wet rebuild.?


Title: Re: Brake bleeding fulvias
Post by: lancialulu on 26 September, 2007, 08:35:44 PM
After a frustrating time once Omicron said just open the bleed nipple at the back and go for a cup of tea. When fluid emerges do same with next and so on. Then bleed as normal. Seemed to work but agree a helper to operate pedal makes it much quicker.


Title: Re: Brake bleeding fulvias
Post by: ColinMarr on 26 September, 2007, 10:22:10 PM
I too can remember having problems in bleeding Fulvia brakes. I found it impossible to do single-handed and I seem to think the crucial thing was to close-off the bleed nipple while the brake pedal was fully depressed by the foot of some helpful assistant.


Title: Re: Brake bleeding fulvias
Post by: nistri on 27 September, 2007, 03:04:37 PM
Using a Gunson closed system bleeding tool (widely available from Halfords) connected to a spare tyre inflated at low pressure (about 1 bar) is the simplest and fastest method to bleed S1 or S2 Fulvia brakes after complete emptying the master cylinder reservoir (something to be done every 12-24 months regardless of use). This tool works wonders even on rallye S and GTE master cylinders with their remote servos (usually the most difficult to bleed). Note that a special fitting has to be fabricated to adapt the tool to the Fulvia reservoir. For this purpose I used a wine bottle cork through which the plastic tube was inserted and sealed. Good luck. 


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 27 September, 2007, 04:38:52 PM
I assume from the presence of an inflated tyre and the cork that one creates a pressure at the filler cap and force fluid through the system?  I was trying to bodge around using a pump from an inflatable matress having decided this was the right approach.Didn't work but your method sounds much more practical.In essence it achieves the same result as the sprung pump on the Aprilia system which makes bleeding the brakes a one man job also.

As there are always plenty of used wine corks around our house I just have to go and look for a spare tyre......


Title: Re: Brake bleeding fulvias
Post by: fay66 on 27 September, 2007, 10:24:22 PM
The Gunson Eezibleed has been around a long time I've had mine about 40 years! must admit though it's a bit disconcerting when you connect in to the tyre & the plastc reservoir inflates :o Always thought one of these days one will explode, but it's never happened.
With pressure pushing the fluid out of the eezibleed, into the reservoir then through the system to the open bleed nipple, there is no chance of introducing air into the system, & it pushes everything before it out of the bleed nipple into a collection jar.

Brian
8227 8)


Title: Re: Brake bleeding fulvias
Post by: nistri on 28 September, 2007, 12:48:43 PM
Yes, it is simple to use the Halfords system. I never saw a plastic reservoir inflating under pressure: it is advisable to use very low tyre pressure.


Title: Re: Brake bleeding fulvias
Post by: fay66 on 28 September, 2007, 05:01:44 PM
Hi Andrea,
The inflating reservoir wasn't on a Lancia I would hasten to had, but with the British Girling reservoirs in the 60's, it was quiter common even using the recommended tyre pressure ::)

Brian
8227 8)


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 28 September, 2007, 06:21:03 PM
Thanks for the tips everyone.This is precisely what I like about the forum.You learn new approaches quickly from people that have dealt with the same problems rather than having to re invent the wheel.thanks.


Title: Re: Brake bleeding fulvias
Post by: Richard Fridd on 28 September, 2007, 06:39:53 PM
one lesson i did learn the hard way was to keep the cap on the brake fluid resevoir when bleeding the system in the conventional way.i once experienced damage to new front wing paintwork with one application of the pedal.cant remember if something was amiss or if this is a general hazard


Title: Re: Brake bleeding fulvias
Post by: chris on 29 September, 2007, 07:44:56 AM
Note - imVho, It is not advisable to COMPLETELY drain a Fulvia Master cylinder (or any m/cylinder for that matter) when replacing the fluid (as part of a routine service), reason being that you run the risk of introducing an airlock into the cylinder. "One" might argue that, by not removing all fluid, that this would mean that the object of the task - i.e. brake fluid replacement - had not be achieved, but don't forget, that, unless you remove and strip all the slave cylinders, you will always have old fluid "hanging around" here, possibly combined with a rusty residue.


Title: Re: Brake bleeding fulvias
Post by: Neil on 29 September, 2007, 10:54:06 AM
Chris, I would agree if you check the level of the fluid and top up as the level falls, before it gets too low, and use more fluid than required, not skimp of the quantity or quality, you should flush out the old fluid and any contamination and take your time you should not have any problems.


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 29 September, 2007, 11:23:40 AM
and in the case where you have to completely replace or dismantle the master cylinder?

The question is how you re-establish  pressure in the system from scratch.Its always undesirable to get air in the system but is sometimes unavoidable.For general bleeding most posts below seem to favour a pressurised system. Does this also work when the system has been completely empty.? ( i read on the internet that whilst the above is effective , there are also vacuum systems that work from the "nipple end" that are "even" easier and more effective to use.)


Title: .
Post by: chris on 30 September, 2007, 06:24:34 AM
.


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 30 September, 2007, 07:33:48 AM
there is no obligation to answer on the forum ; its a matter of choice.

However once information is on here it may save lots of people over the years not being any wiser and all needing to just ring for 2 or 3 minutes for the same information.My reasoning in raising a topic like this is to solve a problem whilst fully aware that this is a common struggle for many people.I also specifically wish to increase the technical content on the forum to make it as useful as it is entertaining.


Title: Re: Brake bleeding fulvias
Post by: ncundy on 30 September, 2007, 09:18:00 AM
Couldn't agree more Scapia. From memory there is a small pilot hole in the front chamber of the master cylinder. The chamber below this is very difficult to prime after the cylinder has been drained. The advice to assemble wet is sensible. I have always filled the master cylinder on the bench and with the actor shaft in the "pedal depressed" position. When released there is then a vacuum in the chamber which helps with the priming. A few pumps of the shaft and you can see the fluid squirting out of the two ports. A little bit messy but you then know everything works before putting it back.
I wonder how many people have re-fitted a master cylinder, been unable to prime it and then taken it off again because they have thought they have assembled it incorrectly ! Thhis avoids all of that.

On the topic of filling the system, when I was designing engine and hydrostatic installations we would always fill from the bottom upwards using a pump. A bit more important in these types of system where cavitation will kill a system quickly if air is not evacuated - so maybe overkill, but I  I may try this when I get round to mine.


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 30 September, 2007, 11:41:50 AM
Thanks Neil, my master cylinder is dry so I'll have a look and see if I can try this procedure.


Title: Re: Brake bleeding fulvias
Post by: chris on 01 October, 2007, 12:29:23 AM
Dear Scarpia - Firstly may I apologise for not reading your original post in this thread - I was reacting to another post contained within this thread - nothing to do with your first post.         
there is no obligation to answer on the forum ; its a matter of choice.         re:- "no obligation" - I note that you appeared to add a post as a reaction to my post, so, Touche!

However once information is on here it may save lots of people over the years not being any wiser and all needing to just ring for 2 or 3 minutes for the same information.My reasoning in raising a topic like this is to solve a problem whilst fully aware that this is a common struggle for many people.I also specifically wish to increase the technical content on the forum to make it as useful as it is entertaining.
                Bravo, is all tht I had better say - but you (and ncundy) seem to be forgetting that all these posts are deleted after a relatively short time, so i'm sorry to say that your efforts would appear to be in vain - (I don't know if there is an archiving system in place that I have missed?)


Title: Re: Brake bleeding fulvias
Post by: chris on 01 October, 2007, 12:46:53 AM
Dear Neil - Re :- "agreeing with Sca(r)pia" - I am assuming you are talking about an early Series 1 master cylinder (?) as later cars could have a cylinder feed hole (the 4mm one?) in both chambers, there later being as many as 3 (such holes) in the rear cylinder, making bleeding easier. Good to see you have taken the trouble to add your bleeding experiences - the "actor" shaft that you refer to, is that like an actuation shaft? Best Regards Chris


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 01 October, 2007, 07:25:41 AM
Chris,
I really don't understand what your issue is. You joined the discussion, but complained you "wished you hadn't bothered" as you didn't want to spend time posting and would really rather people phone you.That's up to you and I understand it in a way because personal contact often does work better. But if others wish to help and continue the discussion that's their choice also.As for an archive, that a whole other discussion......


Title: Re: Brake bleeding fulvias
Post by: chris on 01 October, 2007, 09:31:01 PM
Will respond to you in a p.m. scarpia - I have explained once - and also apologised - I joined the discussion, but was not responding to the original post. You appeared to then respond to my post (which was not aimed at your first post - do you follow?) and then I realised that I had not read the thread from the beginning, and now had to address your question also - a question that I have replied to literally dozens of times. If you knew me, you would realize that, of course I would not hinder the efforts of anyone on this forum to help explain a repair procedure (as long as it was fairly accurate and did not put anyone at risk) - far from it - I would actively encourage it, it saves me a job and new friendships and occasionally, methods can be forged. Chris


Title: Re: Brake bleeding fulvias
Post by: inthedark on 01 October, 2007, 09:48:59 PM
Hi Chris & Scarpia,
It really is time we had a Technical directory so that misunderstandings could be avoided.
It can be wearing when you have to make long posts explaining in simple terms 'how to'
especially when you have covered the same subject several times before. I like Chris
tend to prefer a one to one explanation by phone rather than post to the forum which
can be very time consuming.
best regards to you both
Geoff 'the colonel'
(and I'm very very sober)


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 02 October, 2007, 06:11:37 AM
100% agreed Geoff.
see my posts electronic archiving and countless others over the last year(s). But we can't even seem to get copies of the committee minutes on here (and that is at least forseen already) so I won't hold my breath . Now if you don't all mind , I'm just off to bleed my brakes....


Title: Re: Brake bleeding fulvias
Post by: ncundy on 02 October, 2007, 07:31:06 AM
You little bleeder ................ ;D


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 02 October, 2007, 08:12:37 AM
I've been called worse..I'll settle for that!


Title: Re: Brake bleeding fulvias
Post by: nistri on 02 October, 2007, 01:52:23 PM
In my experience it is difficult to bleed the Fulvia brakes using vacuum pumps applied to the bleed nipples. Much more reliable is to apply gentle positive pressure to the master cylinder.

Again, others may disagree with me, but I always completely empty the master cylinder when replacing the brake fluid. Of course, if there is a lot of old debris in the brake pots, this is not going to be shifted out unless the calipers are stripped down and carefully cleaned.

Fulvia brake pots (S1 and S2) frequently build up rust under the rubber covers which are often damaged by a combination of factors like dirt, high temp, poor quality rubber and incorrect fitting. This of course has nothing to do with brake bleeding but it can affect the brake cylinder movements and pressure on the brake pads.

Finally, on S1 pots the small steel sphere under the bleed screw can rust badly making difficult to bleed the caliper and even causing a fluid leak. A bicycle shop or a bearing retailer can usually provide a similar sphere very cheaply.


Title: Re: Brake bleeding fulvias
Post by: fay66 on 02 October, 2007, 05:47:13 PM
 For the sake of clarity I've added this diagram for those who are not familiar with the Fulvia Brakes, this is the Dunlop set up used on Series 1 cars, the sphere Andrea refers to is highlighted in yellow.

Brian Hilton
8227 8)


Title: Re: Brake bleeding fulvias
Post by: ncundy on 02 October, 2007, 06:35:00 PM
When I stripped the brakes on my car (S1 Fanalone) in addition to the sphere there was a small circular spacer (about 2mm thick). I assumed that they sit under the ball (between the ball and the bleed channel, and the ball butts into the recess in the bleed nipple. They are obviously designed to go there as one side is formed with a recess to house the ball, but they are not shown in the TAV drg, nor in any of the Dunlop or Girling manuals I have. I put them back as I found them - any ideas on this ??


Title: Re: Brake bleeding fulvias
Post by: chris on 02 October, 2007, 11:43:44 PM
Dear Nistri - I would like to refer you to post 13 of this thread in case you missed it - I would strongly advise you NOT to completely drain your master cylinder whilst routinely replacing the brake fluid (by bleeding) as you will run the risk of introducing an air lock into the cylinder. Its true, the chances of this being a problem are reduced if bleeding with the aid of a pressurising device, but if bleeding conventionally by pumping the brake pedal, this can result in much frustration. As for corrosion in the slave cylinders, you could, of course, get these modified to accept stainless steel sleeves thereby ending the problem.  (the front cylinders (2 1/8" dia) need to be machined sparingly with much caution, as there is not much "meat" to work with).  At the same time, I machined the seats of the bleed nipples drillings to accept conventional 45 degree tapers and then used corresponding bleed nipples as used on later Jaguars etc.  Note for Neil - I  remember seeing something similiar on a lightweight alloy Dunlop equivalent cylinder, but I judged it to be an aftermarket fitment to accomodate "shorter reach" bleed nipples. Chris


Title: Re: Brake bleeding fulvias
Post by: ncundy on 03 October, 2007, 07:47:07 AM
Chris, I would tend to agree with you on the spacers. They do not seem part of a "sensible" design as every time you unscrew the bleed nipple they run the risk of becoming unseated and moving, and of course you have no idea if they have seated properly when you re-tighten. At the moment I am not sure what to do (it is not a pressing problem as I will not be in a position to re-fit the brakes for some time), so I will have a think about possible alternatives.
Thanks
Neil


Title: Re: Brake bleeding fulvias
Post by: nistri on 03 October, 2007, 09:26:23 AM
Hi Chris,

Regrettably I don't read this forum as much as I would like, but when I can, I enjoy it.

Well, we have different views about brake bleeding, that I guess is not a serious problem as long as the final result is the same, i.e. good and efficient brakes. In over 25 years of Fulvia servicing I never found an air lock after emptying master cylinders, maybe I was lucky as I suppose this is a possibility: the pressurized system  should however prevent this chance.

You and I have been LCM members long enough to remember a lot of debate about fitting stainless steel inserts into brake pots. Many people had written about this issue in the club mag in the past. Personally I don't like this option very much even if at times it might be the only available one. It may also depend on the car use: I live very near the Alps and, on my roads, brakes must work really hard and become very hot. It is not unheard of front pots failure because, as you correctly pointed out, there is very little metal to bore out to fit an inset.

Unfortunately I don't come often to LMC events but next time it would be good to have a chat and a pint together again. It has been a long time since the last one.

Fanalone brakes: I think the spacers are aftermarket fittings.

Andrea   


Title: Re: Brake bleeding fulvias
Post by: chris on 03 October, 2007, 01:23:47 PM
Thanks Andrea - lovely post - I too, look forward to catching up with you in person one day.  I agree entirely with you on the stainless steel comment as regards the front cylinders anyway. On the plus side, I know of several owners who have had their front cylinders modified in this way and have clocked up high mileages without a problem, (the well-respected engineer Doug Ellis being one of them) so quality of work done could be a factor.   Note for Neil - might be worth considering the 45 degree taper mod?  I know it's non standard, but, although loathe am I to criticise original design normally, the original steel ball bearing/sphere design you could say was a bit "belt and braces" (except braces don't corrode and get stuck!)  I can remember on one occasion having to pump on the brake pedal repeatedly to free off a severely corroded-in ball bearing!  Also, sometimes when you come to strip or inspect a cylinder, you can find that the ball bearing has gone, and someone has replaced the nipple with a taper-type one - and it seems to have sealed adequately (!) Chris


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 24 November, 2007, 11:59:25 AM
Having tried everything else and revised the calipers I still was getting no pedal action and felt like I was just pumping air all the time.I even managed to track down a gunson eezibleed in holland and tried that . It bled the brakes very well one I made an adapter to fit the cylinder cap but still didn't solve the problem at the pedal.Finally I've just taken the Master cylinder off the car and found the problem.The inner piston assembly has siezed in the fully depressed position so the actuating shaft was literally pumping air as it wasn't coming into contact with the piston until the end of its travel.It goes without saying that I need to dismantle it further but in truth I presume if its so rotten as to sieze, just replacing the seals will be a short term remedy on something thats already 35 years old.I think an aftermarket replacement is the way to go but will cost a couple of hundered euros; but then what price safety?.


Title: Re: Brake bleeding fulvias
Post by: ColinMarr on 24 November, 2007, 03:21:00 PM
Scarpia,

Your original master cylinder might not be a lost cause. I would not presume to be an expert, and not that I have ever had one seize in the down position, but I have rebuilt Flavia and Fulvia ones. If you undo the big nut and clean out the bores you are likely to find corrosion pits in the otherwise polished bores. If these are not too deep and horrid you might get away with using the finest of fine emery paper wrapped around a smooth end of wooden dowel to polish them out. Maybe Iíve been lucky, but itís worked for me.

If you do have to resort to a modern aftermarket replacement, I would be interested to know what the options are Ė just in case!

Colin   


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 24 November, 2007, 04:25:01 PM
I'm sure your right Colin .I faced the same problem of corrosion with the aprilia unit but didn't want to risk this approach because of the single circuit. With the fulvia being dual circuit its less risky but the problem remains that once corrosion is set in to the surface of the bore, new seals will inevitably be prone to earlier failure.I'm guessing seals cost 30 quid a time and its a messy job .Ultimately the master cylinder is donkeys years old and a new unit brings peace of mind (at a price though). We'll see...


Title: Re: Brake bleeding fulvias
Post by: lancialulu on 24 November, 2007, 10:43:02 PM
Corrosion is due to corrosion on the alloy due to hydroscopic nature of ordinary brake fluid. I recommend silicone which will generally prevent further corrosion.

Only problem I had was the viscosity of the silicon fluid meant I had to open up the 0.7mm feed hole to 1mm in the reservoir as surface tension (my assessment) was preventing the fluid into the secondary chamber. After that no probs at all.

All my fulvias run on the fluid which has a regal purple look in the reservoir!

Tim


Title: Re: Brake bleeding fulvias
Post by: St Volumex on 25 November, 2007, 04:33:12 AM
Scarpia,

I've had master cylinders resleeved with stainless steel, and used new sealing washer kits with no problems - apart from getting that infamous air lock, when we replaced all our Fulvia's flexible brake hoses.  We rigged up a catheter syringe and sucked the fluid through to the rear calipers.  :-*

I've used the (Dow Corning) silicone brake fluid Tim speaks of, but found the pedal feel wasn't as firm.   ::)

Regards


Title: Re: Brake bleeding fulvias
Post by: Scarpia on 25 November, 2007, 06:38:00 PM
i've also considered silicon fluid as it seems, at least on paper, to be the solution to all the ills of brake systems given its non hygroscopic properties.
In practice I couldn't find it readily here in the shops and this combined with the other doubts I had prevented me trying.I discussed the issue with my old brake specialist when revising the Aprilia brakes and he wasn't keen.It' s actually less of a concern on cars with drums than discs but there are two areas where issues can arise.The silicone lubricates (or penetrates) better than the seal manufacturers original spec takes account of and if the silicone works it way past and into braking areas such as pads you can guess the results. The other more concerning issue is the significantly lower boiling point.Unles you are absolutely meticulous , there remains a fair chance of residual "old fluid"  in the system with its water absorbing properties boiling much more readily and vapour locks leading to potential brake failure.Silicon fluid will experience its boiling condition in a brisk drive in the country where the normal fluid will only reach this on longer mountain descents.

All nice theory of course and the corrosion and water absorbtion of normal fluid are also major disadvantages of the traditional approach. But for these reasons I was advised to stick with normal fluid.Using the vehicle regularly and yearly replacement of the fluid being the least potential trouble in the long run.I suspect the boiling issue is perhaps why major car companies have not switched but knowing how companies work there is probably a financial motive somewhere. 

Not terribly keen on resleeving with stainless I'm afraid as most people secure with loctite which gradually brakes down with brake fluid (but not silicone based fluid i think)

Ultimately a well maintained system avoids most of these pit falls ....now if only I'd done that!



Title: Re: Brake bleeding fulvias
Post by: lancialulu on 25 November, 2007, 10:12:57 PM
Re silicon this is readlily available

Demon tweak catalogue it (Automec) and it is also readily available in my local auto store so I doubt product liaility is an issue. Re boiling point, this is rated at 500def F (260deg C) and is dot 5 mil std. Dot 4 std issue is less. Admitidly racing fluid may give you 50 degrees more  but are your really steaming along that fast???

Re being meticulous - this is the first rule of messing with brakes!!! If it looks dogdy throw it in the bin.

Re brake feel - can comment as i like the feel of my brakes - assume you may have air left in the system which is the curse of Fulvia!

Best and happy motoring

Tim


Title: Re: Brake bleeding fulvias
Post by: ColinMarr on 26 November, 2007, 12:00:37 AM
Silicone or not?

I first encountered silicone brake fluid when I rebuilt my 6th Series Aurelia B20 in about 1990. I thought it was a good idea to use it if only to avoid using the horrid corrosive standard stuff, which strips the paint off the otherwise lovely cast alloy reservoir on the bulkhead.

After investing what seemed like a lot of money for a couple of litres of it, and then losing most of it trying to get the hydraulic clutch mechanism to work properly, I gave up! I abandoned the hydraulic clutch (what a disaster!) in favour of an improvised simple mechanical linkage. I abandoned the silicone brake fluid in favour of DOT 4 mostly because wise people of the time said that the seals of that period were made of a rubber/ plastic composite that absorbed the standard brake fluid which allowed them to expand and help secure the necessary seal. The fear was that silicone fluid would not work in this way. DOT 4 worked well on the B20 and now on the Fulvia and I have not been tempted since to go back to silicone.

Colin



Title: Re: Brake bleeding fulvias
Post by: Scarpia on 26 November, 2007, 07:20:44 AM
Lancialulu,

when I said not readily available here ; "here" means Belgium which perhaps was not clear.

As you can imagine I only proceed at speeds "forseen by our legal framework" but unfortunately brakes get a lot hotter than people realise.A normal town drive can already push the temp. up to the 100 degrees mark.Lengthy descents or racing can easily climb into the 400 + zone hence the glowing discs/calipers that can result.So its at least feasible that water retained in any residual old fluid would be heated much more quickly if basically surrounded by silicone fluid with a much lower boiling point.

It's probably academic .As you say being meticulous is everything and if the system is properly cleaned out then it wouldn't be a problem.


Title: Re: Brake bleeding fulvias
Post by: St Volumex on 26 November, 2007, 08:31:05 AM
I agree with Colin re DOT 4.

I've tried silicone in my Beta too with the same spongy results.

When I went back to 'normal' brake fluid all sponginess disappeared.  ;D


Title: Re: Brake bleeding fulvias
Post by: lancialulu on 26 November, 2007, 06:22:38 PM
silicone or not....

Every one to their own. My HF ran round  various tracks incl goodwood (will there be one in 2008??) with no adverse pedal problems. I like the fit and forget idea - my 1300 has had silicone in since 18 years ago with no seeming problem to seals.

It is more viscous so needs a different approach and yes I spent 2 days once pumping air until I let gravity do its job. Cant say I have ever had a spongy feel to the pedal but they have never been rock hard like my MX5 (oops) which has dot4.....

Tim


Title: Re: Brake bleeding fulvias
Post by: inthedark on 26 November, 2007, 06:54:29 PM
Tim,   << will there be one in 2008 >>  Yes, check Events 2008

'the colonel'


Title: Re: Brake bleeding fulvias
Post by: Jai Sharma on 26 November, 2007, 09:19:53 PM
Hi,
Lots of useful stuff on this subject, from people with much more experience than my own few, no make that several, days grovelling on the floor hoping to find a way to get the air out.....
But just a couple of observations, firstly I too have had a master cylinder stick with the plunger in the body. Couldn't figure out why I couldn't get fluid pumped through....
This happened on two occasions, once when it was rebuilt with new seals and one seemed perhaps a bit larger than it might have been and seemed to cause the brass piston to stick.
The second was, if I recall correctly, on a car that was sitting for a long time, and I think the inactivity meant that the piston stuck when the pedal was pressed.
I do remember pounding around Castle Combe in my first Fulvia and the car weaving quite a lot under braking. The next day there was absolutely no brake pedal - it went to the floor. The seals had failed in the master cylinder.
On the fluid subject, I have never tried silicone, partly because I thought it must inevitably get mixed unless the system happened to be apart in any case. I can see that a system with conventional fluid will take moisture in if left for years, but does anyone know over what time span it becomes significant? I understand if the fluid is changed every couple of years it is fine, but it seems to me that it should take a long time for the water to enter the system and get through the system to a position, and in a concentration, that it can cause much corrosion. I have no idea, but am curious!
Thanks


Title: Re: Brake bleeding fulvias
Post by: nistri on 27 November, 2007, 12:14:54 PM
New Fulvia master cylinder: I would advise inspecting it very carefully before fitting. One thing is to get the master cylinder body (with no plungers, seals etc) and it is straighforward to check it inside. A different thing is to get a fully assembled master cylinder: I have seen two (bought at swapmeets) which had been incorrectly fitted inside and produced very dodgy brakes. The best thing is to open it and check it out before fitting.


Title: Re: Brake bleeding fulvias
Post by: lancialulu on 27 November, 2007, 03:08:02 PM
Furthe to Nistri's post On the fulvia master cylinder the cross sectional drawing in the series 2 concise repair shop manual shows three conventional lipped seals. My experiance with the repair kits is you only get 2 and an o ring replacing the middle one. This may account for some funny behaviour if not assembled right.

On using silicone, I can state that I only use it on a completely rebuilt (new seals all round) refurbished system with not trace of ordinary dot 4. I would not recommend anyone "mixing" the two by just trying to bleed thro...

Tim


Title: Re: Brake bleeding fulvias
Post by: ColinMarr on 27 November, 2007, 06:18:35 PM
A cautionary tale - you donít have to driving hard in order to experience brake fluid boiling! On two occasions with the Fulvia I have experienced that heart-stopping brake pedal to the floor feeling. Both of these were when driving at low speed. The cause was the same in both instances Ė sticking rear callipers holding one of the pads on and hence overheating. It was obvious that one wheel and disc was very hot when I got out to look, but was not easily detectable while driving.

If I were to do another total rebuild of a brake system I would like to use silicone, but I would want to be reassured about the suitability of it when used with say standard Fulvia seals.

Colin   


Title: Re: Brake bleeding fulvias
Post by: lancialulu on 27 November, 2007, 06:31:54 PM
Interestingly my wife bless her drove my then 993 home with the handbrake on (warning light not working) at high speed/100 mile journey. Nothing detected but seriously warped rea disks afterwards - a complete rebuild. Moral - use porsche brake fluid!!

I would like to know if the replacement after market seals are made of modern/compatible materials?? I am sure they will be better than 40 years ago.

Tim