Alfa 1750 alfetta

[b_caswell]

Re: Alfa 1750 alfetta

If you fit a non return valve between the inlet manifold and the servo to stop the ingress of air, it will stop the servo working.

[Blue Marlin]

Re: Alfa 1750 alfetta

Just found this on Alfa parts site while searching for (many, many, many) engine parts

http://www.classicalfa.com/products/EN141-BRAKE-SYSTEM-VACUUM-NON%252dRETURN-VALVE.html

Must have look on my manifold.

[philcoyle]

Re: Alfa 1750 alfetta

The Alpha one looks a bit pricey, you can get cheaper Ford or rover and you may have to modify to fit, but what's unusual about that on a kit car.

[cameronfurnival]

Re: Alfa 1750 alfetta

didnt minis have a non return valve in the inlet manifold?

[philcoyle]

Re: Alfa 1750 alfetta

I think you will find that nearly all modern cars have a valve in the servo hose. Incidentally when you have the engine running clamp the servo hose and see if it alters the running of the engine, if it changes at all then start to investigate the master cylinder/servo joint or just the servo unit itself.
I have a Ford valve in my servo hose, had to remove it from the plastic line to fit it in my rubber servo line, vacuum type of course.
Some valves are in line and others are where they fit into the servo unit, if you can disconnect the hose from the manifold and suck air through the hose then you have a leak in the servo/master cylinder, If on the other hand you suck the hose and expire from lack of breathing, you don't have a problem servo wise, but her indoors may show concern.

[stevejgreen]

Re: Alfa 1750 alfetta

didnt minis have a non return valve in the inlet manifold?

Marinas, Dolomite Sprints, some other TR's all have non returns fitted to the servo.
here or there

[b_caswell]

Re: Alfa 1750 alfetta

Well I stand corrected but havnt got a clue how it works if the engine is sucking on the servo which way is the non return working.

[lil_red_roadster]

Re: Alfa 1750 alfetta

Ben, the valve prevents air being drawn back into the servo...which relies on a vacuum (created by the manifold depression) to provide the assistance.

[Blue Marlin]

Re: Alfa 1750 alfetta

Just found this on Alfa parts site while searching for (many, many, many) engine parts

http://www.classicalfa.com/products/EN141-BRAKE-SYSTEM-VACUUM-NON%252dRETURN-VALVE.html

Must have look on my manifold.

Deffo no non return valve like this on my manifold, must sook my servo when I get the car back in the garage. Great pointers, thanks :O)