The brake servo / booster gets its vacuum from the brake booster pump which is driven from the engine camshaft system. If the cambelt breaks , then the booster pump function is lost .

The OP seems to be saying they drove for several miles with the oil light on, so the servo vacuum would be maintained.

I thought only diesels used a vacuum pump. Why would a petrol need one and what's wrong with the manifold depression?

Edited by bathtub tom on 05/04/2024 at 12:03

Hpi / direct injection petrol engines very often don’t idle with the throttle butterfly near the closed position, so the vacuum at the manifold is not sufficient for the brake servo . A mechanical driven booster pump is used to overcome this situation.

OK, Apology to OP. Didn't know that.

Another "New Car Thing".AKA Progress.

In this case I assume it can't have actually broken, since the car would have stopped. I'd guess it stripped teeth enough to loose drive, without the timing going out far enough for valve interference.

(I'm assuming this is an interference engine, though perhaps the designers thought it didn't have to be, given that it has adequate other ways of wrecking itself).

Seems engine might actually be savable, but I suppose too big a gamble to find out at pro labour rates.

Edited by edlithgow on 14/04/2024 at 00:57