Hey all, a little while back I managed to finish my conversion from a cable operated clutch to a hydraulic throw out bearing. I used a Wilwood clutch master cylinder because it is patterned off of the Girling unit that is used in the 260. It turns out that I had to drill all the holes in the firewall anyways, and everything else was custom, so I could probably have used any m/c. I guess Volvo stopped putting those extra holes in the mid 80s, because my 84 240 still had holes to mount a hydraulic clutch m/c.

The new setup is great, I am glad I did it. Anyways, here is a simple write up that I put on Turbobricks a little while ago:

The deal with the wilwood "small brake/clutch" m/c is that it has a -3 AN female outlet, but it is too deep for a normal -3 male-male union. So the m/c comes with this adapter, which comes out as a 3/8"-24 female inverted flare fitting.


Also, my HTOB came with -4 fittings and line. So I bought a union that was 3/8"-24 male inverted flare to -4 AN. Problem is that this is cumbersome, ugly, and it would hit the firewall. See pic:


Another problem, the adapter that the m/c comes with is really a -3 long, to reach the deep hole. No one sells -3 long to -4 unions. Earl's does make a -3 to -4 bulkhead fitting, so I got one of those, and machined it down so that it was the same depth as the wilwood fitting. It works great.

The bottom part is the wilwood piece to the 3/8-24 to -4 union. See how much longer it would be.


Machining. Oh yeah, the wilwood fitting has what seems to be a 45° angle on the tip. I put a normal 37° on mine. Seals fine. It does appear that the angle in the m/c itself is actually 45°.






Tilton hydraulic throw out bearing on a T-5 transmission. (This is for my V8 240)


Under the dash. The spring is there temporarily because the clevis pin was too long. Also had to drill the 3 holes through the firewall because my car is a 90. Also trimmed the bracket where the pedal is touching, in the upper right of the pic. Turns out that it wasn't necessary, as the pedal stroke isn't that long, so now the pedal is closer to the firewall.


You need to make a pedal stop for the HTOB. I wasn't too crazy about drilling yet another hole, so I used an existing hole to mount the stop.




I started with the .750 bore, but it was too stiff. I have the .700 now, and it is very nice. Pedal stroke is still quite short, so I think I could go to the .625 bore to get even less effort, and it should still move enough fluid. With .625 bore, the clutch effort would probably be Honduh easy.

Oh yeah, the pedal is a 240 cable clutch pedal which was modified. It is now mounted in a higher pivot hole. OH MAN was that a pain to have to drill out. Again, the upper hole might already exist on an early 240. Not on a 1990.

Greg,

Great write-up. I had to modify the hard clutch line and the slave cylinder for everything to work right on my V8. So far, no problems (knock on wood). But if i had to go back and do it again, I would use all GM products to make it more of a plug and play deal.

-Adrian

Is your slave cylinder a GM part? For a while, I was going to do a slave cylinder so that I wouldn't have to drop the transmission. I even made up a bracket to mount a push type slave.

I think that much of my clutch problem was the way the fork was set up. So for me, switching from cable to slave cylinder wouldn't have fixed it. Sometimes the clutch effort was highish, and not smooth, and every once in a while, I would push the pedal, and it would be much lighter and smoother. Something was wrong, and I broke 3 clutch cables in a short amount of miles.

Hey, I saw the pics from the BBQ in CT, looks like a lot of nice cars showed up!

Greg