Rebuild of Clutch Master (1 Viewer)

[sggoat]

Can anyone direct me to a link/thread that details how to rebuild a 1977 Clutch master cylinder?

 

[DougAustinTx]

Just dive in and do it. There is only1 part inside the cylinder, the piston with the rubber boot (unless yours has the assist spring in it). Just clean everything up, smear some fresh fluid into the cylinder and reinstall the internal spring and piston.

EDIT: Whoops, I was talking about the slave, not the master that you asked about. Sorry. Missed too much sleep this week.

 

[tyama]

it's pretty easy. Unhook it (MC) from your line, pull it off the firewall and pedal, get a set of snap ring pilers to get the ring off the end (under the rubber), pull out the old MC (look to see what end comes out last), hone the cylinder with a honing stone and brake fluid, clean out the cylinder with clean brake fluid after honing, put the new MC in with a new snap ring (in re build kit), bench bleed, & re-assemble it all back up, & bleed. you probably want to rebuild teh slave cylinder too as it tends to go pretty soon after a new MC (unless it is pretty new).

Good luck!
best, ty

 

[sggoat]

I think I have a cylinder that it not like the FSM shows(maybe aftermarket) but it did come from Aisin--I'll have to post pics tommorrow--thanks for the feedback--

 

[bikersmurf]

I've rebuilt mine like this twice without even taking it out of the truck. The kit included new seals and a new piston, so there was very little to do to the housing.

Photos 'borrowed' from random web sites.

 

[skidplate]

I guess I've just been lucky, but I've rebuilt several wheel cylinders, clutch master, and slave cylinders without a hone. I just spend some time with sand paper around my finger to clean up the cylinders and then just install the rebuild kit. I always use a little sil-glyde on the rubber parts. I figured if anything leaked after my "red neck rebuild" I'd just buy new cylinders. They really aren't that expensive. It is a pretty simple project. You can do it.

 

[bikersmurf]

Is this more like yours? The principles are the same as brake cylinders. Hone with a cylinder hone or sand to clean up any pitting. Lubricate with only brake fluid and clean with brake clean as required. Youtube will have a similar video I'm sure.

 

[sggoat]

Here's my old one--I can't figure out how to get the piston out--it almost feels like a brake master that has a pin in the housing that you have to remove to get all the internals out, but there is no indication of any such pin-the snap ring has been removed--the cylinder bore is clear -so there is nothing I can see that would prevent the piston removal----
There is some good verbal documentation from my sister that this was never replaced(but then again-her husband did most of the maint)--This CM was in the truck when I got it from her ~ 10 yrs ago-The Cruiser odo has rolled over at least once-may twice), according to her(60K on it now) Seems unlikely that an orig CM would last over 260K miles.
The replacement i got is of Aisin manufacture--same as orig., and has the same inability to get the piston out

 

[skidplate]

Push the piston in and see if you can feel or see whats holding it. I don't recall any type of a "keeper". Might just have a lip that it's catching on.

 

[BigDogg]

Try covering the reservoir hole and using an air compressor in the fluid hole to blow it out.

 

[BigDogg]

Try covering the reservoir hole and using an air compressor in the fluid hole to blow it out.

 

[BigDogg]

Or maybe I covered the line hole and stuck the compressed air in the reservoir hole... Can't remember, but it blew the piston out... good luck!

 

[bikersmurf]

Snap ring? or some sort of set screw through reservoir hole?

Mine is different so I'm shooting from the hip.

 

[sggoat]

There is no snap-ring or "lip" that i can see-it looks clean in the cylinder when you poke the piston down with a screwdriver--when released, the piston returns to a "hard" stop--like there is a lock pin in there somewhere. I can't see anything in the reservoir inlet or the cylinder outlet that looks like it has any kind of lock pin or stop--but I can check again-must have missed something----otherwise, how could they have built this thing?--pics to come--

 

[sggoat]

Blew 50 psi of air into the reservoir inlet-and the master discharge--did not move the piston--should maybe go higher pressure?

 

[Weber Sarge]

Just a note about blowing out pistons such as this or even hydraulic cylinders - make certain you are clear of any liquid that can escape when the piston clears the bore . Also , and the big one - make sure there is something to stop that piston from becoming a projectile . I accidentally shot a huge hydraulic cylinder rod through the shop's front door - which took a day of my own time to fix , and rightly so . I had a stop block set up on the floor , but it could not handle the weight ....lol .
Sarge

 

[BigDogg]

I think my compressor was at 90. Like Weber Sarge said, beware of fluids and projectile pistons. Eye protection a must and point it in a safe direction (I pointed it at the grass outside my garage).

 

[thebigredrocker]

It will absolutely come out. I just did mine. It's just full of crud. Alternate pushing the piston in as hard as you can, THEN AIR.

A Berryman's or Evapo-Rust soak might help also.

Don't NUT yourself

 

[sggoat]

I want to thank ALL of you guys for forcing me to look further into this issue,. A mag glass and good light revealed a couple of rust nibs in the outer bore that was preventing the piston to release--a little 600 grit sand paper took that off, then a sharp bang on the bench and out it popped!--amazing what a little crud can do--anyway, now for the rebuild--
Thank you all again-I love this forum!

 

[skidplate]