Servo brake replace --> brakes still not work

Hello Community

i'm writing this message because i'm stuck with a problem i can't fix since this summer.
I passed my 20VT on the MOT in june and during the brakes test, the brakes were not working.

When i push the brake pedal, i hear like a "pschhhhhit" and it doesn't brake.

So i started by replacig the servo brake with a used part, and after changing it and after doing the brake bleed with my Eezybleed, it still doesn't work.

I followed Fiat requirements by bleeding the front left caliper -> front right -> rear left -> rear right...it still doesn't work.

The guy who sold me the part told me the servo brake was working while it was on his coupé.

One important information : i first used my coop in March after its winter sleep, and i found out that the clutch pedal did not work, my pedal sinked. So i had bleeded the clutch master cylinder, then my problem was fixed


I wonder if my problem is somewhere else... but where ??
I hope you could help me because i'm stucked since this summer and i would fix it once and for all.

Many thanks

Sounds like a master cylinder fault.

What do you mean? what should i check ?

Almost certain Master cylinder problem. Did you have any pedal feel after you used your eezee bleed?

Not the same car, but I had a problem on my old 124 Spider after replacing the master cylinder after snapping off one of the outlet connections. The servo push-rod that goes into the master cylinder was out of adjustment, it was I guess "too long" so that the brakes began to apply themselves and eventually when driving I would have to stop because the brakes were full on. I had to take the car to a garage to get them to adjust the pushrod length correctly, Perhaps in this case the pushrod is "too short" and failing to engage the brakes properly? Or it could be that the master cylinder is faulty? When you replaced the servo, presumably you removed the brake pipes connecting to the master cylinder, then removed the master cylinder, then the servo?

@1200smithy,i have the same result : no brakes, the pedal is tough to push and makes some noize like a "psssssssshit".

I didn't see any improvement.

yes i started to remove the brake fluid tank, then the brake pipes connected to the master cylinder and finally the servo.

Sounds like the connection from inlet manifold (somewhere?) to servo (which provides the vacuum assistance) is leaking, the noise is air rushing in to fill the vacuum. The leak could be in the diaphragm inside the servo. If there's no servo assistance the brake pedal will feel very stiff.

With engine off, pump the brake pedal several times, this will exhaust (use up) any vacuum that is there, and then leave your foot pressing down hard on the brake pedal. Then start the engine: the vacuum that gets created should provide some assistance and the brake pedal should fall a little - if not, you have no servo assistance due to a leak in the connecting pipe, or inside the servo, or I suppose a blockage somewhere ?

If the pedal does drop a bit but not much, switch the engine off (with foot still pressing down on pedal) and then start pumping the pedal: it should get harder and harder each time as any vacuum is used up.

Seems odd that both the old servo and (apparently good) servo give the same problem, in which case the fault is likely to be elsewhere...

the servo i replaced is a used part, the guy who sold me told me it was still working.

Great advice - I will check this out prior to buying a new master cylinder and/or servo