Technical Brake Failure.....

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Technical Brake Failure.....

Jedidev

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Aug 17, 2009
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i was just driving my Brava and i was driving along everything going well came to a line of traffic and pressed the brake peddle and got no risitance and the pedal went to the floor easily and the brakes were working very minimaly.

had no choice but to continue futher to get to a safe place to stop and the after pumping the pedal a few time got them going again. but then failed futher down the road. :confused:

to cut a long story short i checked the pedal and everything seems intact i checked the brake fluid resovour and found the rubber seal on the cap had split could this be the problem? is the pressure escaping from there and thats why the brakes are working and not working?

i tightened the brake fluid cap really really tight and the brakes appear to not be failing now....

any advice would be awesome :D:slayer:
 
Sounds like theres air getting into the system and as your pumping the pedal its bleeding the system, hence the brakes work again. If the cap is split then i'd say that was the problem.

I'm no expert but thats my opinion.

Rob
 
well... did u lose any fluid? or did u had to refill?
btw the tightening dont work, coz it is just for the oil to stay in the reserv.

did u had any breaking just be4 end and till there nothing? - probably 1 diagional didnt work, so u breaked just with 1 rear and 1 front wheel.

test, let engine running and push breaks as hard as u want (think, how u would press if something would happen accident etc.) and hold for ~20 sec...
can u feel pedal sliding down or it is stiff? if u lose pedal over time, eaven a slight moving - would mean some leak... at weels/pipes or main breake silinder.

if this looks ok then what u have is breake main silinder failing... as it loses pressure for some reason... probably happens when some things happen at the same time... i wouldnt reccomend u to drive it hard... as it might happen any time and offtenly happens when u need to break fast... etc....


undo the cap... rubber seals dont want to be very tight,,, just little... and as it is just cap it basically dont have to be air tight...

air would give u some "soft" area for breaks so... if u have.... but not that bad differences from time to time...
good luck
 
Stroke took me ages to read what you wrote. :) I know my England isn't that good but geez. :)

Anyway a common fault on the Bravo is the Brake Slave Cylinder leaking. It can be found on top of the gearbox. If you look underneath your battery tray onto the gearbox you'll see something like this....

9da6_1_b.JPG


If the surround area is wet then obviously you have a leak. Also make sure the brake fluid isn't empty. Its not difficult to fix yourself and relatively cheap too. A new Slave Cylinder will cost you around £40-£60 either from a motor factors or Fiat.

Approx 1hour to sort out. Involves removing battery and battery tray and bleeding. I'm sure someone else will come along with the procedure as I've no time to explain in detail.

Like i said this is a common part to fail on Bravos and therefore I would check this first before replacing other things.
 
srry... i never read 2nd time over to fix grammar.
anyway as i see u have same guess as i have... but eaven if it isnt wet, it doesnt mean it works well..as it didnt fail totally, its probably internal error...
 
JOSKEJTD
Anyway a common fault on the Bravo is the Brake Slave Cylinder leaking. It can be found on top of the gearbox. If you look underneath your battery tray onto the gearbox you'll see something like this....

Please! this is someones life here that could be lost, the part you are calling a brake slave cylinder is the clutch slave, nothing to do with brakes at all, apart from the fact it shares the same resovoir.
You could look there for fluid leaks but if I remember rightly the clutch will go before the brakes, as the clutch feed pipe is higher than the brake feed pipe, or should be!
We never got to the bottom of why they went? was there fluid leakage, did you need to top up, if so how much.
where there any noises when the brakes 1st went, grinding, cruching as it could be front brake pads braking up (happened to mine) the brake surface comes away from the backing and falls apart result no brakes, pumping them brings the backing into contact with the disc again. if you have to top up look for leaks, get the wheels of it and look for fluid aound the calipers, all the rubber flexi hoses a good indication of them is fluid spray inside the wheel arches have a look inside the wheel rims as well are they wet or stained look at rear drums any puddles, drips then take off drums and look at the wheel cylinders push the rubber seals dust caps in and out to expel any fluid thats hiding, if you lost fluid it will have gone somewhere, find it! and still look at the clutch slave on the box as it does feed from the same resovoir as the brake system, don't remeber where the master cylinder is now I think it is inside the car above the brake pedal and fluid there?
Personally I would not drive this vehicle till I had found the problem as it could kill you and others.
 
dont be so dramatic...
u could use "QUOTE" ing so i would understand, about what ur wining....
i have driven a car w/o breaks for 200km.... and ~1/5 distance was in city... so was very annoying... but it isnt impossible... - dont mean i am suicidal.
well would be nice if he would get back .. so we would know what is wrong with it... but well see...
 
thanks very much for all your replies, i've been away on a coach trip so couldn't reply.

well i checked the fluid resovoir and its still full nothing has leaked at all, also did the test of holding the pedal down and it never lost pressure over time and stayed firm.

I did notice however that the black rubber seal on the cap seems to be wasting away. so can i assume that since i overtightened the cap and its worked everytime all i need is to replace the cap? or should i get a mechanic to check it out anyway to be sure?

Thanks again, and i much prefere this site to the other one:), much more helpful and friendly unlike the other site (n)
 
JOSKEJTD
Anyway a common fault on the Bravo is the Brake Slave Cylinder leaking. It can be found on top of the gearbox. If you look underneath your battery tray onto the gearbox you'll see something like this....

Please! this is someones life here that could be lost, the part you are calling a brake slave cylinder is the clutch slave, nothing to do with brakes at all, apart from the fact it shares the same resovoir.
You could look there for fluid leaks but if I remember rightly the clutch will go before the brakes, as the clutch feed pipe is higher than the brake feed pipe, or should be!
We never got to the bottom of why they went? was there fluid leakage, did you need to top up, if so how much.
where there any noises when the brakes 1st went, grinding, cruching as it could be front brake pads braking up (happened to mine) the brake surface comes away from the backing and falls apart result no brakes, pumping them brings the backing into contact with the disc again. if you have to top up look for leaks, get the wheels of it and look for fluid aound the calipers, all the rubber flexi hoses a good indication of them is fluid spray inside the wheel arches have a look inside the wheel rims as well are they wet or stained look at rear drums any puddles, drips then take off drums and look at the wheel cylinders push the rubber seals dust caps in and out to expel any fluid thats hiding, if you lost fluid it will have gone somewhere, find it! and still look at the clutch slave on the box as it does feed from the same resovoir as the brake system, don't remeber where the master cylinder is now I think it is inside the car above the brake pedal and fluid there?
Personally I would not drive this vehicle till I had found the problem as it could kill you and others.

My bad, yes its the Clutch Slave Cylinder, I had brakes on my mind from previous posts which talked about brakes i automatically called it a Brake Slave Cylinder. Theres no such thing unless your talking about the brake cylinders on drum brakes. :)
 
well cap dont make a difference... i think - someone could assure it, would be nice.
about mechanic, i think u might get 1, that steps on brakes and says its ok and ask money for it :S. So wouldnt recomend it...
i would recomend giving ur brakes very hard time in conditions that are safe for you eaven, if u shuld lose brakes... u still can use hadbrake so u can stop sooner or later...
as this fault might be coming back in the worse places...
i broke 1 of my brake pipes at home... when just "out of the blue" i slammed on the brakes... w/o need... well i wasnt allmost moving... so lucky me it didnt happen anywhere else.

anyway... i think if u havent lose brake fluid then it is probably main brake silinder that might cost quite a lot....

if ur going to test it.... be sure to get safe places... dont have to have high speed.... but better make sure they are working in case of u might need them...

safer call would be yeah... swap something...

gl and i hope someone smarter will correct what i have sed ;)
 
Reservoir is not under pressure.

I would imagine the fact you bled your brakes a couple of times has rectified the fault but possibly only temporairily.

A leak in the system could be at fault as Joske said the clutch slave cylinder is a common one. but a leak could be present in a damaged pipe, rear brake piston. or if a brake pad or brake shoe has come apart it would cause loss of resistance until the pad or shoe had rectified or had closed up the gap again.

If everything seems ok then as Stroke says it could well be a damaged seal in the master cylinder.

This definately needs investigation.
 
well took my optimus (brava) to Kwik Fit and they did one of them intensive brake tests and took the wheels off and inspected everything...
and it PASSED :confused:

he put it on this rolling ramp and got to a high speed and stopped the car as soon as he could and it stopped instantly he thinks theres nothing wrong with them at all and it could have been air bubble thats worked its way out.

but i still dont feel comfortable while driving, i'm braking every few hundred yards to make sure they are still working to the annoyance of drivers behind me mind :D but i wanna feel safe and dunno what to do next....

highly confused now lol :p
 
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