(T) Severe Brake Issue on Seicento - Please Help!

(1999 SX 899cc Siecento)

Hopefully someone can help.. apologies in advance for lack of technical knowledge! I have had a search of forums but couldn't find any specific answers.

I got the car last weekend from a mate's Dad - the back left arm that goes from the handbrake to the drum was taken off and free'd up as it was totally stuck. After this I went for a drive, and about 20 miles in, I was slowing for a roundabout (thankfully nothing life-saving) and the brake pedal just went to the floor. Before that it was braking fine. Put the handbrake on and I crept back to his Garage.
Turned engine off, spoke to mate's Dad, when I came back the brake pedal was 'hard' (i.e. stopping the car) again.
He had a guy come round who tightened the handbrake cable (as apparently this is the adjuster for the back brakes). We gave it a fairly decent test and it seemed to have done the job. I did a 150 mile journey without issue, but then yesterday, about 35 miles into a 50 mile trip the same thing happened - pedal is not stopping the car.
Ended up calling the RAC and getting taken back as I did not fancy 50 miles of handbraking.

-The brake fluid is full, and I cannot see any leaks.
-When the car was turned off and I came back to it after a couple of hours for the RAC man the brakes were hard again.
-In retrospect, the fact that that arm that connects handbrake to brakes was seized so much, it must have been like that for a wee while. What issues could that cause?
-RAC guy said could be suspect master cylinder, corroded pipe, or something about air that I can't remember (!)
-When I was dropped off by the recovery guy, pedal worked fine for the 10 or so presses required to park my car


So ... does anyone have any ideas! Its booked into a local garage tomorrow morning but I would be incredibly grateful if someone could point me in the right direction in case they go off on a costly wild goose chase.

Many thanks in advance

I can't see it being anything to do with the handbrake (which is an almost seperate system). I'd think the master cylinder, myself.

its got to be, if you lost servo then the pedal would still operate the brakes - it'd just be a faff. If you lost a brake circuit then the other would still work, and it'd pull funny and brake poorly but still work.

It sounds like the seals inside the cylinder are flipping inside out, and then back again. When was the fluid last changed, does it look dark / grey / black (disolved seals!)

A new cylinder is only about £15, so its not the end of the world.

Cheers guys. I'll have another look at the fluid. It seemed fairly dark but it was p***ing down yesterday so I didn't exactly take a long look.
Should the seals be dissolved/ing would this mean anything else has been duffed or is it still just replace the master cylinder?

Not been to this garage before (only just moved down south) so it's good to have an idea of cost in case they try to pull a fast one.
Any websites etc.. you can recommend to get a new one as if they do try and rob me I'll order it myself and get them to fit it.

Thanks for the quick response by the way - much appreciated.

Master cylinder sounds about right, iirc I was quoted £85 for the repair (which I'm guessing was 1h labor + parts considering how long it took me to do it) from a local garage.

One thing though I found that repeated applications of the brake peddle improved braking performance.

As a simple starting pint, jack each side up and make sure the rear wheels spin without the brakes being on.

I am wondering whether you have something binding producing excessive heat thats boiling the fluid.

Whatever the outcome, change the fluid anyway.

Cheers

PD

That's a very good point, can tell you've diagnosed more cars than me! It would explain why the brakes work, and then don't - and it does it better than a random flipping of seals!

he fixed my cinq many many times !!!!

Cheers Guys.

GoBe - you are right, repeated pushing on the pedal did restore some breaking, although not always enough to stop.

RallyCinq - Unfortunately I haven't got a jack handy - however its going in at 8am tomorrow so i'll pass the above on to the mechanic and see what they find.

Will let you know what the outcome of tomorrow is.. fingers crossed it's sub £100 to fix.

easy way to check for a binding brake is to drive it, let go of the wheel and see if the car pulls anywhere.

and then once you've driven it, pull over and feel how hot each wheel is - if one is binding it'll be much warmer / hotter than the others.

I would go with master cylinder too

front calipers can be quite reliable, the rear slaves can leak but once leaking it will continue to do so

let us all know the outcome wont you?

How would you intend to fix a puncture?

Cheers

PD

he has massive guns.

if repeatedly pressing the brake pedal (or "pumping" it) helps a little, it could be that your brakes need bleeding / changing the brake fluid. If there is some air in the pipes, the brake could drop to the floor and then when you press it a few times, the air gets out and it works fine.

But that amount of air in the pipes would mean you have a leak somewhere.
Not helping much, just giving ideas

Had the master cylinder replaced and since then no issue with braking. Though I haven't been on a long drive... so no idea if intermittent issue is still there.
The garage road tested it 20 miles and found no issue so hopefully its sorted.