Miss Whippys little corsa diesel managed to loose or seemed to loose its brakes, fortunately she rammed the handbrake on as only she can and never hit anything. Since she works at the other side of town she called the AA came out and said that the alternator belt had snapped! Buffoon I thought what the hell has that to do with brakes??! So I looked over the little bucket when she got back and it’s got a vacuum pump stuck on the end of the alternator eh? So basically when the belt snapped the vacuum assist stopped working and she thought the brakes weren’t working anymore…

Why does a diesel need this? Its not a turbo engine or anything, just seems very odd.

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[Edited on 6/10/08 by Mr Whippy]

Probably the standard set up across the diseasel range and is needed for the turbo versions so
used on NA too.

Due to the fact that there is no throttle butterfly in a diesel there is no manifold vacuum on decceleration. It is standard practice for a vacuum pump to be fitted to both turbo and naturally aspirated diesel engines.

HTH

A Diesel engine has no throttle butterfly and so won't make any vacuum - well perhaps a tiny amount but it would have to be a very restrictive intake manifold design.

Hence a vaccuum pump has to be fitted on most diesel engined cars.

Throttling is controlled by injecting more or less fuel at each cycle.

She still had brakes but no longer power assisted brakes. They would still stop her car but more pedal effort needed on her part, get her a thigh master so she can build them up ready for next time and she can practise by rolling downhill with the engine off and braking.

quote:

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Originally posted by Peteff
get her a thigh master so she can build them up ready for next time

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slight thread hijack, but the vac pumps... can they be re-piped to make a small compressor ? if they can i may have an alternator change comming up