Clutch slave cylinder

The Ferrari part number is 500259. As can be seen from the photo it does not have the casting seam around like the original and has NB02 stamped on the side, but overall a good replacement for the original slave.

Do you know if the bore is the same as the original piece?

Technicaly the stroke is the same and controled by the linkage.

Denis

Hi Denis, Yes I have measured the bore in both at 19mm and the supplied pushrod is a few mm longer than the original and a smaller thread, but still usable and you can always reuse the old rod. Mike

I think the angle of that shot did not present the slave well. If you take away the casting centreline flange then the slaves are very similar, apart from the numbers and the additional lip on the original near the fluid input.

Great find!!!!

Just for reference...the Fiat X1/9 "early" kits will work to rebuild an original Goose cylinder if you have yours re-sleeved with brass etc.
The early kits were just a wiper seal...and maybe an o-ring that doesn't get used.... The later kits come with more parts!

(.750" bore...Girling parts...English measurements!? S/B same as master cyl bore.)

There are at least two different X1/9 setups with different pistons too! I picked up a few old Fiat slaves from X1/9's and recently fitted one of the slightly more modern pistons into my older slave body. I had kits for that style so, figured what the heck, try it and see! Seems to be working just fine! I do still have some original style seals with new pistons that I picked up from some guy down in Brazil many years back....if anyone needs one.

My notes say seal# 51940-00999NRC I believe this is the number from the original Girling style umbrella seal.

You guys down under may still be able to find the late style X1/9 kits under Beck-Arnley #071-5789 Also under Wagner F103530. Lemmeno if you find them!

Steve

You can get a Mangusta clutch master cylinder replacement from Summit but with a 0.625 inch bore part number 260-6087 for $47.95 which will reduce clutch effort as well

Ben,

That is all correct, however, you reduce the travel of your slave cylinder....and risk damaging your expensive ZF synchronizers if you don't know what you are doing.......

Sometimes I wonder if putting a bigger fluid line from the front to the rear wouldn't make a difference....! There just isn't any reason that there should be that much pressure on the foot pedal.... Girling .750 components are used in a lot of other cars/trucks....albeit with perhaps smaller engines....and therefore smaller pressure plates.... but to me it would seem like the leverage advantage of the clutch pedal would make up for it.....??? ...not a hydraulic engineer....!

Steve

A hydraulic system versus mechanical does nothing to reduce pressure, it is only a device to make the execution of the clutch movement easier to be achieved from a packaging standpoint.

The force that is built into the pressure plate through the choice of the springs is the cause of a heavy or light pedal.

Changing the diameter of the master cylinder will only increase or decrease the required travel of the pedal giving very little reduction in required foot power.

I can tell you from first hand knowledge of the J code 302 that most likely the entire issue with clutch pressure is the change from the "original assembly line" pressure plate to an aftermarket.

As supplied by Ford in the engine assembly, the pressure plate was rated at 2,600 pounds.

If you went to buy an exact replacement for it from Ford over the Ford Parts Service counter, the "Ford rebuilt", which was the ONLY way the clutch was serviced, was rated at 2,800 pounds.

It is very close to being 100% accurate now to state that virtually ANY BRAND pressure plate is going to be 3,200 pounds.

There in lies the problem.

The car was engineered for the 2,600 clutch.

In the case of the Mustang, there is a mechanical connection, not hydraulic, from the pedal to the clutch throwout bearing lever.

In that assembly there is a part called the "z-bar".

That bar now with any replacement clutch needs to be reinforced so that it does not twist under the added load of the heavier replacement clutches.