406oc.co.uk

Hi guys. May I present, for your consideration, an outstanding opportunity for you lucky people to help me further my knowledge of the 406!

In other words, what's this part, please? ^_^

I gather it's something to do with the brakes...

I take it you mean the big black round bit? That's the brake servo, also known as a "brake force amplifier". I believe its principal of operation is to take a vacuum from the engine and use it to assist the brake hydraulics somehow, with the assistance being proportional to the pressure on the brake pedal.

Now you mention it, I think I'm going to have to look it up and find out exactly how it works

Anyhow, the whole engine vacuum thing is the reason you only get about 2 assisted presses of the brakes with the engine off, before braking involves pushing HARD into your chair (yes, I've made that mistake in a traffic jam downhill... )

mjb, since you answered first (and I going to assume correctly since, as we all know, assumption prevents f*ckups)