I have been struggling with the bleeding, bleeding job on the Fiat, and that is in spite of buying an all singing and dancing vacuum bleeder...helpful hint: PTFE tape on the threads of the bleed nipples.
I think it's now done but the pedal travels too far before all four brakes are activated; I don't think that it's sponginess through air.
The thing is that there is reliable information saying that all wheel cylinders should be the same size but I know that the fronts I was supplied with are a bigger diameter without the rears being smaller (as far as I know) than standard.
Does anyone know if this means the master cylinder may not have enough capacity and this would give the symptoms i am experiencing?

I have the same Peter bigger ones should be on the front. The bible says they were all originally the same size 3/4 inch which translates to the size of the smaller ones on the rear.

As you know I had loads of little leaks after bleeding the brakes the first time around, the pedal had some travel with the leaks but it wasn't horrendous. I would double check tomorrow to see if you have any leaks at any of the joints, they can take a while to manifest themselves. I am using synthetic fluid which is very light but the leaks would appear a bit quicker in theory.

Is it a new master cylinder?

Thanks Tony; that cheers me up a little. The only leak I spotted was on the one pipe end I did myself of course! As the vacuum bleeder works in reverse of normal bleeding, it sucks air in through any bad joint and that was at every bleed nipple.
I was just worrying that the displacement of the master cylinder would be insufficient to make up for the extra capacity of larger front cylinders.
I need to give it a drive to centralise the shoes hard up to the drums. The problem now is it is playing up as thry do and not wanting to rev thtough the range. Already spotted the mixture screw is missing its "O" ring. PS...all new bits

The movement on the pedal is most likely down to the springs pulling in the shoes on the self adjusters . You can either stretch the top spring a little or just drive it and it will probably settle in.

Toshi 975 said:

The movement on the pedal is most likely down to the springs pulling in the shoes on the self adjusters . You can either stretch the top spring a little or just drive it and it will probably settle in.

Click to expand...

Ah ha! I like your thinking. Thanks.

Hi Fiat 500,
the shoes should centralize in the drum 'static' (ie undriven) or driven.
The culprit of my 'bleeding' dramas turned out to be the rear flexible hoses. When I investigated the heavy, long pedal-stroke braking the score card was :- collapsed/blocked rear flexibles, contaminated shoes LH front from a slow weep and a working (hallelujah!) RH front.
From the lack of wear on the rear shoes it looked like they hadn't been working in ages. I changed all the flexible hoses.
Regards
Viv

Thanks Viv. I may have to move on to check those thjngs, but for now, since every item is new I'm going to wait and see if it's the tight springs causing it.
I must admit that I was surprised how easily the drums went on meaning that the shoes had probably already been pulled back from being in the optimum position.
Peter

Thanks again Toshi. That was a top tip. I just manually pushed the brake shoes on all four wheel as close as I could get them to the drums whilst the drums could still be put on without force. I did also do another bit of bleeding which produced a small amount of bubbles.
The brakes are rock solid now although they still need bedding in and whilst better than my 1930s car they are a long way short of my modern.