405 TD Feels like loss of servo on brakes

[GSB]

On my wifes 95 1.9 TD when applying brakes for a short time everything seems fine. When applying for a longer period, say when descending a steep hill after 4-5 seconds pedal feels sort of dead and then need to press much harder to continue braking.
Any ideas please.

[pug_owner2002]

I had this on my 306, when it happened I could also hear a hissing noise from the brake pedal area.
All cured since replacing the servo (£153 from the main stealers).
I would check the vacuum pipe to the servo etc as this could be the problem.

[AndersDK]

Yep check for leaks in the vacuum servo, hoses, non return valve and vacuum pump.
The pump may be checked while engine is idle, as then there should be a very noticeable suction from the vacuum source hose.

My guess its either the vacuum source hose (general rotten condition with surface cracks), the non return valve or any valve fitting rubber seals.

[GSB]

Thanks, I will check above.

[greg123]

Turn the engine off. Wait a minute, then depress the brake. You should hear a 'hiss' and get 3 or 4 pumps before it goes solid. If it's solid, you have a leak. Pump it, then start the car with your foot hard on the brake, it should immediately sink. If it holds vacuum, but builds pressure up very slowly it's the vacuum pump. If it loses vacuum, it's servo or pipe.

If the above is okay, it's other brake issues and a full service & bleed is advised.

Greg.

On my wifes 95 1.9 TD when applying brakes for a short time everything seems fine. When applying for a longer period, say when descending a steep hill after 4-5 seconds pedal feels sort of dead and then need to press much harder to continue braking.
Any ideas please.