Brake problem, cant stop.

[Edge]

My 300tdi 90 brakes are spongy on 1st press then solid on 2nd, but no matter how hard i press the pedal i cannot come to a sudden stop or lock the wheels.
Approaching a zebra crossing at 30mph, i thought...."plenty of time i'll brake and let the old couple cross"..... it just kept bloomin movin, ended up front wheels on crossing and old couple laughing cos i was head up against the roof full weight down on the pedal.
Just changed all pads.....(old ones were okay, but put new in anyway)... and i'm still having the same problem :shock:
Any ideas anyone :?:  :?:

[Bob696]

Have you bled the fluid through? Might be an airlock or water or just knackered fluid

[Edge]

I'll try that today, Thanks Bob :D .

[fatusbloke]

Once bled fluid though starting at furthest point from master cylinder, check also, brake vacume as you say brakes are going solid on second press but no effort this sounds more likely to be the problem, also check wheel bearing as a loose bearing can push back the brake pads, which is why you get nothing on the frist press the the pedal go's firm at the next,
 but lack of effort is most likely lack of brake vacume, tdi's have a seperate vacume pump for this

[Edge]

Once bled fluid though starting at furthest point from master cylinder, check also, brake vacume as you say brakes are going solid on second press but no effort this sounds more likely to be the problem, also check wheel bearing as a loose bearing can push back the brake pads, which is why you get nothing on the frist press the the pedal go's firm at the next,
 but lack of effort is most likely lack of brake vacume, tdi's have a seperate vacume pump for this

 :shock:  :shock:  :shock:  :shock: I'm getting confused :shock:  :shock:  :shock:
I'm a bit of a total novice when it comes to mechanics :roll: , could you go into a bit more detail on how i check the vacuum :?:
I may phone Redlinemike and plead with his goodside to accept some beer tokens and come down and spend a full day sorting all the minor glitches out.

[Porny]

Being a 300Tdi,

Most likely the vacuum pump....  if this stops working (which they have a habit of doing) then basically you loose your servo assitance, so you have to press the pedal a LOT harder to get the Landy to stop!!

There is no real way to test this AFAIK, more of a diagnostic....



Ian

[Hangover]

Pull the vacuum pipe off the brake servo unit,with the engine running stick your thumb over the end and it should suck,if it don't then the vac pump or pipe work is the problem,if it sucks then put it back and listen out for any hissing noise around the servo area.
Kev

[Edge]

Will try that in a minute.
In the meantime....is it possible that i have water in the system from driving along/in the river at Drumclog :?: , its quite deep in places and i did have to come to a complete stop due to other vehicles ahead stopping.

[Xtremeteam]

Will try that in a minute.
In the meantime....is it possible that i have water in the system from driving along/in the river at Drumclog :?: , its quite deep in places and i did have to come to a complete stop due to other vehicles ahead stopping.

nah
only way you could get water in the system is be stopped stuck with water over the bonnet

[Edge]

Vacuum pump seems to be ok  :shock: .

[Edge]

Pull the vacuum pipe off the brake servo unit,with the engine running stick your thumb over the end and it should suck,if it don't then the vac pump or pipe work is the problem,if it sucks then put it back and listen out for any hissing noise around the servo area.
Kev

Another way ive found "hope this is useful":-

Press brake pedal repeatedly (with engine off), until pressure builds up. Keeping foot pressed on pedal....start engine. If pedal sinks the vacuum pump is working.