Page 1 of 1

M50 - servo vacuum

Posted: Mon Feb 14, 2022 6:34 pm
by Phid
I have just got my M50 running successfully after a long lay off (over 3 years).

The hose between inlet manifold and Clio brake servo is insufficient and is collapsing- I assume this could be causing revs not to drop quickly after blipping throttle?

I will replace it with a stronger hose - but does it need a non return valve in it?

Also there is some top end knocking. I haven’t revved the engine hard yet but assume this could be a stuck lifter? Will check plugs to ensure all ok before revving.

Thanks for any guidance.

Re: M50 - servo vacuum

Posted: Mon Feb 14, 2022 9:39 pm
by DanThe
Air leaks in general can stop the revs dropping, can also be temperature related if the engine is not running perfectly
NRV is not 100% needed, but it does keep vacuum inthe servo rather than letting it escape to the intake

Lifter tick is very common, make sure you have enough oil in, get the engine hot and the lifters usually sort themselves out

Re: M50 - servo vacuum

Posted: Mon Feb 14, 2022 10:07 pm
by Phid
Thanks Danthe (by the way you’ve just done an exhaust for me).

Ref the engine noise - sounds more like a knock than a tick but maybe just terminology. Definitely top end. Oil is at right level - 10w/40 has been used. I’ve ran the engine to temperature once (not for long) but haven’t given it any revs. Do I need to give it some (bearing in mind it’s just on headers and down pipe at the moment!)?

Re: M50 - servo vacuum

Posted: Tue Feb 15, 2022 7:27 pm
by DanThe
Great :D sounds like you need to get a system on it next job, you need to rev it yes which will raise the oil pressure

Re: M50 - servo vacuum

Posted: Tue Feb 15, 2022 7:43 pm
by Phid
Thanks - will do that