Poor brakes

[Defender110]

and new flexi front lines as the old ones were starting to "blow" under pressure

yep thats one i had forgotten about

regards malcolm

This can also quite often be the cause of sticking brakes even with perfect calipers. Old brake hoses can collapse internally blocking the hose, the pressure applied by the brake pedal forces the fluid through but the collapsed hose acts like a one-way valve preventing the fluid returning.

[vulgalour]

While we're on the subject of brakes, I'm trying to figure out if Stripey has a brake problem or not. Before the pedal box was repaired, the brakes felt good and like those on a normal car. Now, with everything back in place, the brakes seem just as good but there's a lot less travel in the pedal and it feels too hard, to my BX-innocent foot at least. I'm used to the brakes on things like my non-servo Polo, the servo-assist Princess and Dad's decidedly more modern Omega and they all feel normal, the Polo being the hardest to use.

Is the hard brake pedal just a quirk of the BX, or is it something I should be worried about? The car inspires confidence when braking, but the pedal won't go anywhere near the floor.

[Defender110]

If you have less travel now than before that sounds like the pedal brake spring piston we have been talking about may have been welded up too?

[rutter123]

While we're on the subject of brakes, I'm trying to figure out if Stripey has a brake problem or not. Before the pedal box was repaired, the brakes felt good and like those on a normal car. Now, with everything back in place, the brakes seem just as good but there's a lot less travel in the pedal and it feels too hard, to my BX-innocent foot at least. I'm used to the brakes on things like my non-servo Polo, the servo-assist Princess and Dad's decidedly more modern Omega and they all feel normal, the Polo being the hardest to use.

Is the hard brake pedal just a quirk of the BX, or is it something I should be worried about? The car inspires confidence when braking, but the pedal won't go anywhere near the floor.

never had a bx with any amount of travel on the brake pedal, i believe the bx brake system works on opening a pressurised valve to pressure up the brake system, hence you only need a little pressure, as opposed to a regular servo unit which runs from a vacuum to assist brake pressure. if you have a lot of travel on a bx brake pedal then i would guess you have more serious probs. im sure someone else on here could advise you more or correct me if im wrong.

[Dollywobbler]

Compared to anything else, BX brakes feel rock hard. The pedal will never go to the floor. Servo brakes always feel mushy. BX brakes are more like non-servo brakes, so I find the pedal behaviour very similar to my 2CV (albeit with far less pedal pressure needed!).

I may try new front hoses. The brakes have now been bled.

[ghaddon1701]

Agreed with above once the pedal comes in contact with the button on the doseur (there is usually a centimeter or so of free play. I tried reducing the free play on my TZD and all it did was make the brake light switch stop working. Realised it was this after replacing the brake light switch with a new one and then that playing up after a short while.) the pedal should be rock hard. you can compress the spring if you push hard enough but you will have gone through the windscreen if you tried this while driving the car.

[MULLEY]

I prefer the lack of brake pedal movement as i find the amount of foot pressure being applied to be much more intuitive than relying on the vast amount of travel of normal cars. My mini may have a much better braking system, but i still prefer the feel of very little pedal movement tbh. If you're worried about BX travel, don't try a DS with its mushroom shaped brake pedal, zero movement, haha....

[ghaddon1701]

How does the BX fare braking wise compared to a Mini Cooper S? Could a BX with ABS match the stopping power?

[citronut]

as others have said with hydraulic citroens your foot dose not create the braking pressure, all your foot dose is opens a valve to varying degrees, as the pressure is there all the time hydraulic pressure is up

regards malcolm

[mat_fenwick]

Agreed with above once the pedal comes in contact with the button on the doseur (there is usually a centimeter or so of free play. I tried reducing the free play on my TZD and all it did was make the brake light switch stop working.

A centimetre sounds like a big gap to me - I wouldn't be happy driving mine like this. Perhaps the little rubber button between the pedal and the plunger is missing? If you adjust the free play you can adjust the brake light switch so it comes on correctly. I've set mine up with a welded up spring, and as little free play as possible. So braking is more of a case of stroking the pedal rather than pressing it!

As for comparing with a MINI Cooper S, both are capable of activating the ABS on dry tarmac so wheel traction rather than brakes is the limiting factor. I suspect the BX wheel would follow the irregularities of the road better due to sorter suspension, but the MINI weighs more so would potentially have more traction (but more momentum!) I wonder which would be more resistant to fade with repeated use? Certainly with solid discs I find the BX brakes heat up quickly, although the 16v vented ones are much better.

[Kitch]

Brakes on the 16v are shite. Not sure why yet, possibly air in the system.

[MULLEY]

How does the BX fare braking wise compared to a Mini Cooper S? Could a BX with ABS match the stopping power?

The Mini will stop much quicker, the tyres have more grip, the ABS system is more advanced than a BX one, bigger vented disc brakes with much bigger brake pads, then you've got Anti Skid Control system on top of the ABS, its a different beast as its much quicker & also a bit heavier, so it needs to stop quick. I've only on one occasion had to really hit the brakes hard & the back end did feel a little light as i wasn't braking in a straight line & i was downshifting at the same time, not ideal braking conditions tbh, but it was of my doing. The BX would have crashed if i'd tried that same manouevre. Having said all that, i still prefer the brake pedal feel of the BX.

[citronut]

A centimetre sounds like a big gap to me - I wouldn't be happy driving mine like this. Perhaps the little rubber button between the pedal and the plunger is missing? If you adjust the free play you can adjust the brake light switch so it comes on correctly. I've set mine up with a welded up spring, and as little free play as possible. So braking is more of a case of stroking the pedal rather than pressing it!

you do need a bit of free travel at the pedal, i think if you adjust it all out you will be verging on your brakes draging all the time,

also if the rubber button was missing your drivers foot well would be a swimming pool of citro blood

regards malcolm

[mat_fenwick]

you do need a bit of free travel at the pedal, i think if you adjust it all out you will be verging on your brakes draging all the time

I've adjusted it so there is a minimum of free play, not so it's in constant contact as I agree that wouldn't be a good thing!

also if the rubber button was missing your drivers foot well would be a swimming pool of citro blood

You've probably seen a lot more BXs than I have, but I assumed they all had (when new) a rubber 'boot' over the plunger where the pedal presses onto it. Nothing to do with fluid sealing, as mine has been missing for at least the last 120k miles. It was on a low mileage example I saw it but maybe it's usually missing?



It was over the plunger in this photo.

[electrokid]

i believe the bx brake system works on opening a pressurised valve to pressure up the brake system,

2 valves actually - one allows main hydraulic pressure through to the front brakes, and another to allow the hydraulic pressure that 'happens to be' in the rear suspension through to the rear brakes.

If you put a heavy load in the back then the auto levelling will increase the pressure in the rear suspension to achieve that - when braking that additional pressure in the rear suspension is applied to the rear brakes so automatically compensating for the additional load. Liking that a lot I am

i find the amount of foot pressure being applied to be much more intuitive than relying on the vast amount of travel of normal cars.

Me too