90 Hdi Braking problems

[mflynn1971]

Hi
I have just joined the forum. I have a 2002 406 90 Hdi rapier model. On three occasions over the past year the servo has failed to kick in during braking. The brake pedal felt the same as if engine was switched off - rock hard. Had a local Peugeot garage look at it but they found nothing unusual. I happen to know the mechanic so I think they made a decent effort. It happened during very wet weather the first two times so today I took it through some big puddles(about an 1" of water covering the road) and managed to repeat the failure. It stayed like this for up to 10mins. Went in to a shop and came out after another 10mins and they were back working again. Anybody any ideas?

Mike

[Welly]

Well, I have never ever heard this one before

I can't think how the water could affect the brakes like this.

The vacuum required by the servo is fom a vac pump on the end of the camshaft (RHS) you could have a look at the vac hoses just to check for splits etc. occasionaly the vac pump fails but that is normally accompanied by lack of turbo boost too.

[mflynn1971]

It works perfect 99% of the time so most components must be ok. Does you know if there is an electrical component to the power assist. Up until now I thought it was purely mechanical at that end i.e. a mechanical valve switched by the brake pedal which switched vacuum(which is supplied by a shaft driven pump) to one side of diaphragm only to actuate brakes. I thought the electric bits were further along at the abs end. Am I mistaken?

[jameslxdt]

vacuum pump or a faulty brake servo