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Old 09-30-2008, 01:23 PM   #1
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volvorod85's Avatar
Join Date: Feb 2003
Location: Sunny Socal
Default Making your cable clutch hyrdaulic in your 240

I will be editing in pics ad finalizind text shortly....

First a quick background on my car. Its a 1986 245 DL that was N/A with a AW71. Its now a 2.5l penta with a T5 and MSnS. This will still apply to M46 owners and possibly M47 cars also, with any red block.

I did this conversion because I could never get a clutch cable that would last very long without becoming unbelievably stiff. No matter what I lubricated it with, it would last a few days then give my left leg quite the unnecessary workout.

So far as I know, at least here in the stated, the only factory hydro clutch 200 series was the 260, and good luck finding a manual 260 in the boneyards, let alone a 260. I priced some factory parts such as the clutch pedal from the dealer and prices upwards of $180 just for the pedal pretty much made me decide to do it the way I did. I wanted to keep it simple, and reliable.

Parts I used:

1. Clutch slave cylinder from a 700 series turbo
2. Hydro push type clutch fork from 700 series turbo (there are other options, ill get to this later)
3. Wilwood small brake/clutch master cylinder with a .750" diameter bore
4. 1/8" x 1" flat bar
5. 1/2" x 1/2" square stock
6. 1/4" fine thread male rod end with universal 1/4" clevis pin
7. 36" -3 steel braided line with one end converted to a -4 due to adaptor sizing needs
8. 2 fitings, one -3 with a crush washer for the master cylinder, and 12mm x 1.0 to -4 with a crush washer for the slave cylinder

Tools I used:

1. Mig welder
2. 1 7/16" hole saw (though a 1 1/2 would probably be a better size)
3. Small grinding stone to go into drill (as the 1 7/16" hole was slightly to small for the master cylinder)

The process is pretty simple and self explanatory, but I will go over everything either way.

I had already taken the dash off to replace the blower motor, it's pretty easy to remove anyway, so I personally suggest to remove it to make this process a lot easier.

Start by removing the clutch pedal and the small long bolt that's behind the pedal. If your lucky you already have a cover plate overing the hole for a master cylinder, if you not like me you will have to drill out holes for the master cylinder. I went to OSH and picked up a dewalt bi-metal hole saw for steel, 1 7/16". You may want to go with a 1 1/2" though, after i drilled the hole I had to hone it out a touch more to fut the master cylinder. I also drilled out the 2 mounting bolt holes. Then test fit the master, my bolt holes didn't quite line up so some more filing was required. I used 2 8x30mm bolts, nuts and lock washers to mount the master. Bolts through the firewall from the interior, nuts in the engine compartment.

Then I realized the pedal has to be moved up because its no longer pulling a cable, its pushing the master. The other holes were already drilled into the factory pedal box for me. I cut the tang for the cable clutch off and mounted the pedal to see where I was. The pedal ends up being about 2 1/2" too short. The pedal is hollow. I used 2 peices of 1/8" x 1" x 3 1/2" flat bar to lengthen the pedal. I used 1/8" because the thickness of the metal used for the pedal is approximately 1/8" so welding would be easy. I cut the pedal at about the 1" thickness area and jammed the 2 pieces of flat bar into the lower section of the pedal and welded it up, them measured 2 1/2" and made a mark, slid the top portion of the pedal over and welded it up. Just try to make sure the halves are straight the pedal doesn't end up cocked to one side. Then I welded the seal down the flat bar. Its most defiantly as strong as it was before.

Then I test fit it again to make sure the length was cool. Next I had to attach a rod end to the master.
NOTE: When you order the master cylinder order a rod end also. The thread is 5/16" fine thread!!
I picked up a 5/16" rod end to only to find out i was handed a reverse thread end. All I could find locally was 1/4" and 3/8" SO i picked up a 1/4" male threaded rod end. I had to make a reducer as the only reducers I could find were course thread. So I also picked up a 1/2" x 1/2" piece of square stock, cut of approx. 1 1/2 inches, drilled it all the way through, and tapped the 1/4 fine 1" down and 5/16 fine went about 1/2" down. I also cut the rod on the master cylinder because it would have been way too long, then attached the parts accordingly.

With the master completely assembled, I also installed the pedal and measured the length from the pedal to the master, again cut some 1/8" flat bar, used the grinding stoned to carve out the shape of the pedal shaft and marked where the would have to go on the pedal. With the pedal at the top of the stroke the master much be fully extended. If you have cruise control make sure the pedal is pretty much resting on the cruise bypass switch in the pedal cluster.

NOTE: I made a mistake, if you look at my picture with the tangs on the pedal, they are farther back then the pedal itself. The tangs MUST be welded on the pedal so they are parallel with the pedal! This insures you get maximum travel of the master cylinder with minimal movement of the pedal. With the way it was set up previously there was not enough stroke, so the engagement of the clutch took the entire stroke of the pedal. With the tangs parallel, the engagement is correct.

Weld everything up and reinstall the pedal to double check where everything is at, eyeball the hole for the clevis pin and drill it out. You should have some adjustment with the rod end to get everything lined up properly. At this point you should be done here.

Now under the car, T5 or M46 you still use the Volvo bell housing. There are 2 ways you can do this.

1. The stock 700 series hydro setup with a push type slave cylinder and clutch fork (this is how I did it)
2. Wilwood makes a pull type slave cylinder you can probably use with the stock pull type cable clutch fork. I didnt go this route because You have to fabricate a way to hold the pull slave, And the push slave was a bolt in.

I used the stock 700 slave cylinder. I yanked the trans cause i had to install a new clutch anyway. The cable clutch has the pivot on the pass side of the bell housing. Its held on by a bolt on the back of the bell housing accessible from the top right side of the bell housing. The hydro has the ball pivot on the drivers side of the bell housing. I already had a modified stock clutch fork for the T5, I went to the dealer and bought the ball, stud and clip for the hydro clutch fork. If you look at the bell housing there is a small tower with a hole, this is where the stud and ball go. There should be a nut already behind the bell housing as you cannot access it with out removing the bell housing. Every M46 Ive seen has a nut there from the factory. Then put the clutch fork on, put the trans back in and install the slave. Its just that simple.

NOTE: You want to make sure the fork is perpendicular to the input shaft of the trans with the release bearing just touching the pressure plate. This insures maximum travel of the fork with the least work from the slave. I had to buy a slightly longer stud and add some washers to move the pivot ball out further to get the fork at the correct angle. If you are careful, you can do this without removing the transmission as the hole in the bell housing where the fork goes through is huge.

As for the line, there are tons of ways to do this im sure. The master is set up for brake line type components. I went down to Earl's (yes THE earls is about 10 miles from where I live) I got a -3 to -3 adapter that fits perfectly into the master, and since its all machined, i just used a crush washer. The stock slave has a 12mm x 1.0mm thread pitch and again, is made for brake line. I got a 12mm x 1.0mm to -4 adapter and sealed it with a crush washer. Earls modified a prefab 36" -3 steel braided line to have a -4 end. Hooked it all up and bled it, no leaks!

My results were perfect. A smooth controllable engagement without the stiffness I had from the cable. I'm currently running a clutch net 6-puck disc with a red 2X pressure plate.

And as everyone else said, this is informational only, your results may vary!

2019 Buick TourX <-- Daily driver
2009 Honda Fit <-- Wifeys ride
1982 Austin Mini <-- Wifeys toy
1959 Austin Healey Sprite <--something completely different (my project)
1974 Fiat X1/9 <--Mom's little toy (next project)
1982 Olds Custom Cruiser LQ4 <--Dad's beast

"Driving the old 2 valve 740 is a bit like driving an IKEA wall unit, so leisurely is its acceleration, so angular its lines."

My former brick saved my life 6/25/03....Volvo for Life

Last edited by volvorod85; 10-20-2008 at 03:40 PM..
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