HELP Brake Failure!!!

[acf8181]

Had brake failure this morning thankfully with nothing to hit! Brake pedal went solid and wouldnt move (felt similar to when you have no servo assistance but engine was on) and had zero retardation (i.e. it wasnt stopping it in slightest). Did it for a few seconds then returned to normal, but then did it again and didn't return to normal for a few minutes, had to even turn round using only handbrake).

Upon parking there is a hissing from rear wheel, however had just been through a ford (this was after the brake issue happened) so could just be a small tyre leak.

Also worth noting have been trying to track down an odd noise from one of the wheels, had one wheel bearing changed by a garage which silenced it a bit and he suggested other wheel bearing was going as well.

Any ideas? Is costing me a day of wages already and money is tight so i really need to investigate myself. Is a 2002 Xsara VTR HDi (mods can you please leave this in general gassing for a while as need responses)

[BliarOut]

Mechanical obstruction of the pedal? Check all the mounting points in the footwell and be sure to get upside down so you can see above the pedal box.

If you're unsure pay someone, brakes aren't an area for experimenting

[Nick M]

Agree about checking the pedal for any obstructions.

Also wondering if the ABS system is going a bit tonto, maybe due to a dodgy wheel sensor, which is causing the solid feel you get from the pedal, i.e. it's the ABS kicking in when it's not needed ?

Finally, maybe check for any pebbles or crap in and around the brake calipers - unlikely, because the other calipers should still work, but then again it *is* a Citroen...

[acf8181]

Cheers for the responses guys...about to go out and investigate now i have daylight

Both had crossed my mind, its not stuff rollingaround floor as keep my car empty but will have a look up behind dash. Would ABS not vibrate (as it does when it kicks in) if it was playing up though?

[mnkiboy]

Wonder if it's possible that as you drove through the Ford you've picked up a pebble which has lodged itself in the brakes somewhere. Had this happen to me once - had a small amount of braking on one side. When I took the wheel off to investigate i'd pushed so hard i'd bent the brake pad, and the friction material detached from the back plate when I removed it.

[Gafferjim]

Mechanical obstruction of the pedals with the carpet or similar, maybe.
Also check the air pipe connection to the servo from the inlet manifold, this is what "sucks" the vacumn into the servo, that gives the assistance.
After these obvious checks, as has already been said, take it to a reputable garage.

The hissing from the rear wheel is probably a slow puncture.

[The Black Flash]

Definately sounds like something's jammed somewhere. If there's no braking at all it would suggest something at the pedal or servo end, rather than a calliper (though you never know - but that's were I'd start). Scary stuff.
Edit - had something similar with a clutch pedal on an old nissan years ago - the pedal mounting had actually torn, so pressing the pedal was just bending the mounting, not actually moving the actuator.

[SmilerFTM]

I had a similar problem in my first car, the brake pad had somehow shattered causing the brakes to fail. As has been said check them all, something could be stuck in them

[BOBTEE]

Gafferjim said:

Also check the air pipe connection to the servo from the inlet manifold, this is what "sucks" the vacumn into the servo, that gives the assistance.

This, although with it being a diesel you'll more than likely have a vacuum pump rather than just using the inlet manifold. The pumps themselves can fail. If you were to disconnect the pipe with the engine running you should hear hissing, no hissing = new vac pump required.

[Flatinfourth]

You do need to be absolutely clear on your symptoms. on a car like that surely you would need a pedal/linkage obstruction to have no retardation whatsoever. the Xsara is just a lead on from the ZX/306 with as far as i know no exotic systems fitted. I hasd a 405Mi16 years ago with no pedal whatsoever but that had a ridiculous electric powered sphere powering the master cylinder, effectively giving the car single circuit brakes in a failure. In conventional servo systems the servo only reduces pedal effort, but sometimes by a massive level, making the car hard to stop without the servo. I'm guessing that your car has the vacuum pump on the engine providing the sucking function for the servo, any fault with that renders the servo useless. if the car were here i would test it in open safe space with you by rolling along with the engine off and pumping the brakes to empty the servo of vacuum, to see if the consequent hard pedal is what you thought you had before.
Good luck

[Ozzie Osmond]

The Black Flash said:

If there's no braking at all it would suggest something at the pedal or servo end, rather than a calliper (though you never know - but that's were I'd start).

^^^^ This.

[acf8181]

Thanks for the responses....its been in the garage and they cant find whats wrong! Picking it up in a moment and will driving very cautiously.

On way to garage i tried rolling down hill with engine on to see the effect of no servo on this car and it was fine, pretty decent amount of retardation.

I'm going to go through with them exatly what they checked.

Is a very worrying time!

[jon-]

acf8181 said:

Thanks for the responses....its been in the garage and they cant find whats wrong! Picking it up in a moment and will driving very cautiously.

On way to garage i tried rolling down hill with engine on to see the effect of no servo on this car and it was fine, pretty decent amount of retardation.

I'm going to go through with them exatly what they checked.

Is a very worrying time!

You'll find the first few applications of the brakes with the engine off are fine, then the pedal will get REALLY hard really quickly and offer almost nothing.

Pump it a few times stationary on the hill (handbrake) then set off and try.