Lancia Motor Club

Model Technical and Interest => Fulvia => Topic started by: dhla40 on 12 August, 2010, 04:54:46 PM

Title: Master cylinder
Post by: dhla40 on 12 August, 2010, 04:54:46 PM
I have a spare master cylinder from a S2 that I have resealed but during bench testing I could not get the front piston to pump.  Thinking the seal was damaged I stripped it down again and noticed that the reservoir for the front cylinder did not have the inlet port drilling as shown on my part drawing in the S2 concise manual item 5.  The only orifice was the one next to the piston stop screw which is behind the cup seal of the front piston. Does anyone know if the design of the superduplex cylinder changed and for what reason.


Title: Re: Master cylinder
Post by: lancialulu on 12 August, 2010, 08:06:28 PM
Sean I think the hole may be there but it is very fine c.7mm from memory. It could have corroded up?? I seem to remember I had a similar problem a few years ago with the fluid not wishing to drop through so I opened it up to 1mm and all has been fine since. I dont recommend this. It was only my solution!


Title: Re: Master cylinder
Post by: dhla40 on 12 August, 2010, 09:33:53 PM
The rear cylinder has the drilling in the centre of the reservoir but the front has only the large hole for the intermediate chamber and the stop screw for the piston. On further invest I think the front piston has a sort of valve that allows fluid past when the piston is at rest but closes as soon as the piston moves. I just thought it strange that the drawing in the manual shows the same inlet port drilling for front and rear.