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Replace clutch slave cylinder and bleed clutch

36K views 7 replies 7 participants last post by  444 
#1 ·
Well, the reason for replacing the clutch slave was just a horrible hemorrhaging from the seam between the slave and the tranny bell housing. No problems at all with operation.
So, pulled the Squash into the garage and put the front up on ramps





Here is the slave on the passenger side of the tranny. You can see I think where it has been oozing down the side of the tranny. {oil under there too from oil filter housing gasket}





I'm not sure if this is advised, but first I clamped off the line from the brake reservoir.



Next is where I messed up a little bit. I removed both of the 13mm bolts holding the slave to the tranny.




**Notice gasket in between slave and tranny**

What I should have first done is loosen the 12mm fitting to the fitting on top of the slave. Doh! I was still able to get it loose, but it simply would have been better to break that fitting loose while still secured to tranny. Lesson learned.
Here are old and new slave cylinders, along with gasket. There is a rubber seal/bladder in the front of the slave, and the old one looked horrible compared to the new one.



 
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#2 ·
I want to point something out about the gasket. I may be totally wrong about why, but notice there are 2 diagonal channels in the bottom end of the gasket {channels point down}. I believe this is so that if the slave develops a leak it gives the fluid a place to run out and not get all in the bell housing. Maybe not......



You can see the marks from this on the tranny bell housing



OK, back in with the new slave



Put your 2 13mm back in and tighten down.
Next took me quite a while, and you could so profoundly screw-the-pooch here if you aren't careful. You have to thread the 12mm fitting back onto the top of the slave. Be so very careful not to cross thread here. I spent almost 15 minutes trying to make sure I got this right. In the end I was a little hesitant to put the wrench to it as I sure couldn't hand tighten it very far, but it worked out fine thank goodness.



NOW, the dreaded clutch bleeding: :eek:
After reading about clutch bleeding over the last 4 years I certainly wasn't looking forward to this. I did a bunch of searching this morning on the various ways to go about this.
I thought about using my still-never used pressure bleeder and bleeding from the slave fitting up through to the brake reservoir, but there really isn't any way to control the flow. It is just "on" or not.
So, basically I did pretty much the same thing, only using the right front brake caliper and reverse bled.
Worked well for me.
First I went and bought 3 feet of 3/16 fuel line and some Dot 4 brake fluid. I filled the brake fluid reservoir to full and I removed the clamp on the line from said reservoir that I installed earlier. I attached the 3/16 fuel line to the slave bleed nipple and opened it some.



The thought was to maybe let some fluid run down from the reservoir then connect it to the RF brake caliper bleed nipple. And, that worked pretty well. When I got a little drip I connected to the caliper nipple and opened it up. {Uh, btw, I opened it a little too far and puked brake fluid out during pedal pumping. Just an fyi}



So, just to clarify at this point, the brake fluid reservoir is full,



3/16 hose is attached at the slave cylinder and at the RF brake caliper and both bleed nipples are loose.





Then you simply step into the car, with the hood open and leaned/standing out the driver's door so you can see the line coming into the brake fluid reservoir and pump on the brake pedal and watch for bubbles to start floating up. {Which they did!} Oh, and you do nothing with the clutch pedal during this.
Now, like I said, I first left the RF caliper bleed nipple too loose and it oozed quite a bit of fluid, so I tightened everything back, opened them up a tad and pumped the brakes some more. When no more bubbles came up, but I could tell fluid was entering I tightened both nipples, started the car and prayed it would shift into reverse with out grinding. {I chose reverse in case the car crammed into gear and wanted to "go". Better to shoot off the ramps than over them.}
We'll see after I drive it awhile if I have to re-bleed. I'm hoping not.......
 
#5 ·
Great write-up. I started replacing mine today and was too frustrated to put the new one on after getting the old one off so I put it off till tomorrow haha. Anyways, did your new slave cylinder come with a new gasket, or did you just use the old gasket?
 
#6 ·
Those two channels in the "gasket" are not to drain leaks and the "gasket" is not a "gasket." The "gasket" is a spacer, and the channels in the spacer are for the insertion of the clutch checking gauge.

A flat u shaped piece of sheet metal with a specific width in the center of the u is inserted into the channel. If it goes all the way in, that indicates that the clutch is worn to the point that it needs replacement before the rivets dig into the flywheel. This is indicated because the smaller diameter portion of the clutch rod is exposed to the gauged area.

I have one of the gauges somewhere, but the dimensions can be found in a Haynes manual so that you can make your own.


Using the bleed of a brake cylinder to bleed the clutch is an accepted clutch bleeding procedure described in many truck service manuals.
 
#7 · (Edited)
I took a look at my cylinder in my 84 300d and getting to the 12mm hydrolic hose on top seems to be the biggest pain. Could it be easier to un-thread it further back where it attaches to the soft tube, remove it with it still attatched to the cylinder, install it on the new one and then mount it? Or are we doomed to wrestle our fingers in that tiny space?
 
#8 ·
I was wondering what you were talking about then realized that you have a 5 cyl. There's enough space on the 4 cyl.

Anyways, if you think that way's easier then try it. You'll also have to remove one of the bellhousing bolts because the line's attached to one of them.
 
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