Clutch System Related Questions

Joined
3 November 2011
Messages
3,607
Location
Saskatchewan, Canada
I did a clutch fluid flush on my NSX yesterday. I sucked the grungy stuff out of the reservoir, filled with new and the plan was to vac out the fluid from the slave until it came out clear. I figured that since the fluid in the system is > 11 years old, it should be easy to spot when new fluid had completely filled the system. However, the > 11 year old stuff in the lines looked pretty much new (unlike the stuff exposed to air in the reservoir) making the distinction between old and new a problem. I vacuumed about 1 of those small bottles (350 ml) of Honda DOT 3 through the system and quit. I looked in the service manual and couldn't find anything on the system volume. Does anybody know what the system volume is? Towards the end I could have been vacuuming new stuff out because everything looked pretty clean.

While I was 'down there' I also serviced the slave - clutch fork contact point with the wonderful urea grease. I don't have a lift so the car is jacked up and I am on my back doing this. As in the past, I just pull the rubber boot out of the clutch housing, try and peel it back, squirt some brake cleaner at the ball - fork point, try and wipe off the old grease and dirt and then blob some urea grease around the edges of the ball - fork point. It works; but, because you can't get the boot off or separate the contact point with the slave in place it is probably far from perfect. To get the boot off and complete access to the slave - fork contact point you need to remove the slave from the clutch housing. Has anybody tried removing the slave without disconnecting the hose to the slave first? With the hose in place, I could see one of the mounting bolts and I could feel; but, not see the other one. Finger space is already limited in that area and I figured that if I rounded off one of the bolt heads I could really screw myself on any future clutch slave replacement. I didn't want to remove the hose because I had just finished the flush (sequence of execution is everything!)
 
Since only a very minimal amount of grease separates the ball from the fork during use I would think that when the car is at operating temp the grease will flow into the area and there would be little to no advantage in taking anything else apart. In my experience knowing when to quit is critical - In the past I have caused myself untold grief trying to optimize things when it wasn't really necessary.
 
Since only a very minimal amount of grease separates the ball from the fork during use I would think that when the car is at operating temp the grease will flow into the area and there would be little to no advantage in taking anything else apart. In my experience knowing when to quit is critical - In the past I have caused myself untold grief trying to optimize things when it wasn't really necessary.

I won't dispute the 'know when to quit' observation. On the grease flow question, the Honda urea grease is a high temperature grease and the claim to fame is that it remains in place when hot, so I don't know how much flow there is. That said, cleaning and slobbering the grease around the end of the extension on the slave piston with a Q tip has eliminated the squeak and gritty pedal feel for now.

Perhaps a more pertinent issue is that you really have to manhandle and fold back the rubber boot to expose the piston - fork interface. My boot remains fairly flexible and a little silicone sprayed around the lips of the boot helped pop it back into the housing. On some older cars that operate in a very hot climate I would not be surprised to have the boot tear or split in half when bent back the way I had it to access the fork.
 
Now I’ll have nightmares where the boot splits. Seems like what you do while not a complete cure manages the symptoms. Often the best course of action in car repair, medicine, and lots of other things.
 
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