Technical Spongy Brakes?

[Fatcatvera]

All sorted, thanks for your help everyone.:slayer:

Just to add an update to this. The parts available are still an issue. I bought a new complete set of brakes from Ricambio (UK) recently and have just fitted them during the rebuild of my car. The spring force of the supplied springs is greater than the friction available from the friction devices and the shoes just slide back to fully compress the slave cylinder after the brake pedal is lifted. The causes long pedal travel, but a firm pedal once the shoes contact the drums. The springs supplied measured 99mm overall, but once stretched to 109mm overall and then refitted the problem was resolved.

Video of the issue (hopefully works...)

Spring as supplied - 99mm Overall length

After Stretching - 109mm overall length

 

[fiat500]

Just to add an update to this. The parts available are still an issue. I bought a new complete set of brakes from Ricambio (UK) recently and have just fitted them during the rebuild of my car. The spring force of the supplied springs is greater than the friction available from the friction devices and the shoes just slide back to fully compress the slave cylinder after the brake pedal is lifted. The causes long pedal travel, but a firm pedal once the shoes contact the drums. The springs supplied measured 99mm overall, but once stretched to 109mm overall and then refitted the problem was resolved.

Video of the issue (hopefully works...)

View attachment 449196

Spring as supplied - 99mm Overall length
View attachment 449197

After Stretching - 109mm overall length
View attachment 449198

Excellent demonstration of the issue and a solution.

Apart from the fact that the original, factory-supplied springs were no doubt tempered to a more exacting specification and sizing, I suspect that the original-style, adjustable friction washer arrangement allowed this sort of annoying issue to be more easily overcome.