Brakes pedal hardened

[cg]

Folks,

Today after parking at a sloop (30% inclined), my brakes behaved strangely.

It cannot stop the car to a halt after reverse from the incline.

The brakes work after the first depressed. After subsequent depress after releasing the first depress, the pedal will feels hardened then my nightmare will start. The car will not come to a halt.

After driving for a while, the brake pedal will softened and it will work again after the first depressed. Then subsequent depress will will hardened the pedal. This whole cycle will go again.

No fault from the idrive and my rear brake pads has been changed for more than a month. Front brake pads still have many kilometres to go.

Wondering if anyone can give some advise what could be the possible root cause ?

 

[moots]

bro i take that the engine is running all the time ya?
coz if the engine is off then the brakes will be stiff as the vacuum in the brake booster will have been exhausted.

stiff brakes will most likely be due to the brake booster not operating correctly.plse check the vacuum lines from the manifold to the booster and check that they are not pinched or have collapsed due to ageing rubber hose.

the only other thing is the brake booster itself is faulty...

plse rectify this ASAP.needless to say,inefficient brakes are dangerous.

 

[cg]

Yes. the engine is running when the drama happens.

any ideas the price of the brake boaster?

 

[cg]

bro i take that the engine is running all the time ya?
coz if the engine is off then the brakes will be stiff as the vacuum in the brake booster will have been exhausted.

stiff brakes will most likely be due to the brake booster not operating correctly.plse check the vacuum lines from the manifold to the booster and check that they are not pinched or have collapsed due to ageing rubber hose.

the only other thing is the brake booster itself is faulty...

plse rectify this ASAP.needless to say,inefficient brakes are dangerous.

Moots,

Apparently, diesel don't take the vacuum from the manifold... there is a pump within the engine.... : (
http://www.partsbase.org/media/images/bmw/c3/c3d086fe533cb2d8c0e95ab02b3ae9e5.png

There are traces of oil in the vacuum hose.

Not sure where is leak coming from.