[rsj]

:confused1: I just replaced the "no-name brand" standing pedal clutch master cylinder for my 1969 Spider from one of our main suppliers with an OEM Beniditalia from Classic Alfa as it was leaking (after only a few years). Lucky that Classic had one on the shelf. I decided to replace the ATE clutch slave also (can't quite remember when it went in, it was so long ago) as I was worried about it blowing out with a new master cylinder.

Here's my confusion: The newer ATE clutch slave I bought 4 yrs. ago from a well-regarded supplier is different dimensionally from the one that was in the car. It is longer, has an internal spring, and the rod that pushes against the clutch throwout fork has no threaded provision for adjustability. (see pictures)

From alfabb threads which I can no longer find I seem to recall the later clutch slaves did away with the external return spring, but what is puzzling is that the kit came with the plate and spring for that, even though the spacing of the grooves for the retaining circlips would not allow the installation of the plate (see photo).

Now I'm really puzzled - would not pressure from the internal spring pushing on the piston (and rod) take up any freeplay in the actuation and possibly allow wear on the pressure plate fingers? Can someone help me visualize this? Would not the extra length of the cylinder lead to the need for an adjustable rod (I installed the non-adjustable one and also left out the plate to which the external return spring attaches, as it would not have allowed the second circlip to seat )?
Thanks in advance.

 

[Alfajay]

would not pressure from the internal spring pushing on the piston (and rod) take up any freeplay in the actuation and possibly allow wear on the pressure plate fingers?

I see your point, and think you are visualizing it correctly. However this system does seem to work without causing excessive wear. I suppose this is because the force exerted by the spring inside the cylinder is not that great, so the T/O bearing is just "kissing" the PP fingers - not pressing hard enough to cause rapid wear.

Would not the extra length of the cylinder lead to the need for an adjustable rod (I installed the non-adjustable one)

Hydraulic clutch mechanisms tend to be self-adjusting. So while your new slave cylinder is longer, as long as its piston doesn't hit the stops at either end of its travel, it will be fine.

 

[yvesmontreal]

Alfa started using hydraulic clutches with the 1750; a 1969 is one of the earlier cars so equipped.

I do remember from a 1750 I owned in the 70s that the clutch linkage had a threaded adjustment which disappeared with the hanging pedals. The slave used from that point was different. I believe they now supply the later cylinders for the early cars. I don't have further details about the spring.

 

[rsj]

Thanks gentlemen. I will leave as is, bleed it, and monitor it closely till any concerns I have disappear.