Master Cylinder

The message from James contains these words:

Trouble with old master cylinders is that in my experience they tend not to like being bled. I've always put this down to either a ridge of wear in the bore or perhaps a patch of corrosion in an area which the seals don't usually reach except when the pedal goes right to the floor during bleeding, but I could be wrong.

Unfortunately, seal kits are increasingly hard to get so the chances of repairing it when it happens is low.

Of course - you could get round this by pressure bleeding so that the piston doesn't go right down the bore - but though I like pressure bleeding I'm not sure this is a terribly good reason to use it.

No doubt someone will pop up now and condem any second hand safety critical parts - but that rather implies that if they buy a second hand car they'd replace the braking and steering system - which I suspect they don't do.

It's a real pig in a poke. Do you really want to go to all the trouble of fitting one and then find it's duff? You can replace the seals, but that's no guarantee that the cyl. will work for long when finished. I suppose if you dismantled it before you bought it and checked to see if the walls were pitted then you'd be off to a good start. But somehow I don't think a vendor would let you do that.

Rob Graham

New is best, but if you buy a secondhand one then see it on the vehicle and check that the pedal is nice and firm and that the fluid looks clean and that the top hasn't been left off to fill with water. Flush it through with new fluid and fit it. A new seal kit would be nice but bear in mind that some kits are not available or are very expensive, so check before dismantling. Personally I would fit new cylinder if possible or just put on (without dismantling) a secondhand one that feels good as a second choice.

mrcheerful

The message from James contains these words:

What's the car? Master cylinders often turn up for things like Montego/Maestros and other memorabilia on eBay as New Old Stock (NOS).

Vectra, and it's on eBay at £2.99 + p&p no bids (along with a host of other bits from the same car).

I'm in the market for one so just wondered if it was worth a punt if it stays at that price, not really a lot to lose...

Anything of this nature, always buy new - ultimately it's safety issue, and you don't know how badly worn the old part will be etc.

If it isn't on the car - is the car a write-off - and is that because it crashed, and did it crash due to brake failure ......

And you'll guarantee every new part is perfect? No matter where it comes from?

Even if it did crash through brake failure, why does it have to have been the fault of the master cylinder?

Yeah but by that argument one should never buy a 2nd hand car, it's got

The message from "Dave Plowman (News)" contains these words:

I should imagine true brake failure leading to accidents is extremely rare. Pilot error causes just about all accidents.