Brake advice please!

[Scott]

Hi

Having had a rather hectic time of things lately my Fulvia hasn't had an outing for many months. Getting it out yesterday for a summer evening blast I had a rather disconcerting experience where the brake pedal effectively just went to the floor offering minimal braking ability. So after 200 metres of slow driving down my road and pumping the pedal and drawing a negative on anything obvious like brake fluid loss I returned home.

My car is a 1.3 Series 2 Coupé and the last time I drove the car the brakes were fine. Clearly something has deteriorated over the last few months to cause this (master cylinder internals?) but I would be grateful at this stage for any advice. There is barely any braking capability and I can push the pedal all the way to the floor.
It's bad timing as whilst a competent home mechanic, time is my enemy over the next few months ... but I'd like to get the Fulvia out on the road before summer disappears!

Many thanks.

[Dikappa]

only two possibilities IMO:
1. Check thoroughly for any loss of brak fluid, it can be a pipe or hose, or the master losing fluid into the servo booster.
2. If there's no leaks the master cylinder is the main suspect....

[lancialulu]

This can happen to S2 Fulvia master cylinders after a lay off. I have found normal operation can be resumed after a lot off quick pumping. If not then the master cylinder need dismantaling cleaning and resealing. That assumes the bores are fine. There is a valve internally that some times gums open. Pumping can restore function.

[Scott]

Thank you both for the replies.

I did pump the pedal several times when I drove the car but will do it over a longer period tonight to see if there's any luck there. Fingers crossed!
If however this is not fruitful and the master cylinder does indeed need "dismantling, cleaning and resealing" then is this a relatively straightforward job that an amateur competent mechanic (me!) could reasonably do myself? Do I need any special tools and if something has deteriorated inside that needs replacing are these parts easy to get hold of (Omicron?). I've done lots of things on my Fulvia over the many years I've had it but never needed to do much brake work and certainly never anything on the master cylinder!

[stanley sweet]

I had this a few years ago. The pedal went to the floor but because of the Duplex system it still had the small pistons working at the front. When the brake pedal was pressed there were air bubbles coming up in the M/C. I bought a seal kit from Omicron and this was fitted by a neighbour who   knows his way around cars. Still the same. Further inspection revealed tiny pitting in the master cylinder probably caused by water absorbed  into the fluid over many years. A new M/C with the new seal kit and all was well again.

[lancialulu]

you can rebuild the master cylinder if you are careful in photographing how the internals are organised. I suspect the tiny internal valve ( you can dismantle and clean but need small tools to deal with the circlip) may be not be sealing. New rubbers anyway. The middle rubber seal is replaced with an o-ring in some kits which is not a problem. If you are nervous I have heard good things from members who have used a company called Past Parts
http://www.pastparts.co.uk/ especially if you need the bore sleeved. You can buy replacement cylinders at a cost........

[Scott]

Thanks for all the replies.
I've got a master cylinder seal kit on order and will have a go at this myself.
Hopefully this will be a case of a failed seal rather than a corrosion issue but we'll wait and see.

[stanley sweet]

Have you got the red covered Fulvia workshop manual? There's a cutaway of the master cylinder in there if you lose track of the seal order. Think I've seen them on Ebay or pretty sure Omicron will have them.

[Scott]

Thanks Stanley; that's a sound tip. I do have a copy of the manual so will dig it out and absorb carefully before I let myself loose. I quite like some hands-on mechanical work and fingers crossed I can get things up and running again (or rather stopping!) in short order.

[nistri]

When reassembling the master cylinder it is critically important that the screws in the reservoir are tightened while the pistons are pushed forward to prevent crashing and damaging the internals. Andrea 

[Jai Sharma]

Lots of good advice here.
I had a similar experience a long time ago when the brake pedal just went straight to the floor when getting into the car. I'd been going around the track just the day before....
Anyhow, it sounds to me most likely to be the m/c. When you re-seal it, bleeding it can be a little fiddly. There are lots of tips on how to do it, and worth looking them out. 

[davidwheeler]

But the best way is to get one of these  http://www.eurocarparts.com/ecp/p/tools/car-service-tools/brake-service-tools/brake-bleeders/?SEAVS020&0&    I have saved so much time...!

[Scott]

Managed to make fair progress on the master cylinder this weekend.
The large nut at the end of the MC was a swine so after struggling with an adjustable wrench I ended up splashing out on a proper 32mm socket, and I won't say this that often, Halfords came to the rescue with some 'shock and unlock' spray which despite my dubiousness actually seemed to have a positive action.

Internals of the MC look fine; there was a lot of gunge in the end that goes into the servo but I've diligently cleaned everything so in the main all good.

I have managed to damage one of the circlips though. On one piston the circlip came of easily; on the other it eventually did but the tip has fractured. I've measured the shaft at 5.9mm but does anyone know the size I should try and seek for a replacement i.e. I assume a circlip is measured on the basis of the groove it will clamp into. I've found the following on ebay ... http://www.ebay.co.uk/itm/M5-5MM-EXT-EXTERNAL-CIRCLIP-PACK-OF-10-MODEL-ENGINEER-/112454907361?hash=item1a2ed5b5e1:g:qU4AAOSwB09YMZ8y  that look similar but is 5mm too small?!

I also have a bit of a 'mystery' with regard to the seals which I'd be grateful for advice/clarification on please! So in the attached picture of my MC components, seal 'A' was not originally present on my MC but was included in the replacement seal pack I received; this is the only place I can see it would go though! Conversely seal 'B' was present on my MC when I removed it from the car but was not included in the replacement seal pack. 
Having replaced the four seals on the pistons I've now also got a seal 'C' left over 
I could put all this down to an error with whoever packed the seals but since my MC definitely didn't have 'A' I'd like to check! I've had my car for around 25 years and no work has ever been done on the MC!

On the subject of checking could I just double check a couple of other things please?! For seal 'D' I gently prised this up and slipped it off the piston shaft. On putting the replacement on I then started doubting myself on the orientation i.e. did it flip over when I took it off. So long story short should the open cup part of the seal face inwards (like the seal at the end of the piston)? And then in a similar vein part 'E' definitely goes on that way round right?! 

Sorry for all the questions... 

[davidwheeler]

...which is why I now take photos before dismantling anything but, sorry, did not do so when I dismantled my MS many years ago.    You may find something via Mr Google though.   If all else fails, Omicron will be able to tell you.
Can you not measure the diameter of the groove?  If the shaft is 5.9mm you may find the groove is 5mm.   If the groove is 5.9mm then you will need a 6mm clip.

[davidwheeler]

Like this for instance