clutch master, dis-assembly ???s

2005 Ranger, Ford (I think) clutch master cylinder installed 6-7 years ago during a clutch job.
I want to remove the MS pushrod, I can see the snap ring holding a collar that holds the push rod. My question is does that snap ring also hold the plunger in, or is there a second snap ring to hold the plunger? not really in the mood to spill brake fluid on the floor if that 1 ring holds everything in.

next question,,, since pushing the shaft pressurizes the cylinder it would seem there has to be some sort of 1-way valve going up to the reservoir. if that's the case, then how do the bubbles come out the reservoir during reverse bleeding??? does the 1-way only close under pressure? if reverse bleeding is attempted too fast will that close the 1-way?

Problem:
clutch pedal is soft until the bottom, doesn't release enough to get into gear so I'm quite certain there's air in the system, like at the top of the MS
I've seen the videos and know that the MS needs to be inverted to get the air bubble to the ports. and the one about using the brakes bleeder to reverse bleed it.

I have an old MS and slave on the workbench for experimenting. maybe, just maybe, I can devise a better bleeding method.

There is a retaining clip inside the master cylinder piston that holds the pushrod in place and it's more or less permanent... which is why the instructions that come with new master cylinders say not to install it until you have to. I believe the snap ring you're looking at will allow the whole thing to come apart.

The one way valve is the quick connect fitting at the slave cylinder end of the hose. Bubbles rise during bench bleeding because of a) gravity and b) to a greater extent because fluid is being pushed past them and into the bottom of the hose. Eventually during bench bleeding, the piston will get so tight that you can barely move it - that's when you know you're done.

did some exploratory surgery, details and pic to follow soon.



that's a clutch master in an upright position, the left hose goes down to the slave.





now the hose points up, it seems both hoses swivel,,,more about that later



yes, after the clip is removed the entire plunger assembly comes out.




that is the bottom end of the plunger, take note of that round ring in the center


OK how does it work,,
lets start with a functioning system, full of fluid and no air.
in the static, or "at rest" position the ports to both the slave and the reservoir are open. fluid is free to move in or out of either. the slave port is in the side, the reservoir port is the bottom of the cylinder.
start depressing the pedal, the plunger assembly starts going down, the very first thing that happens is that center ring contacts and seals and blocks off the reservoir port, thus sealing off that part of the system. the pressure is now directed out the slave port and magic happens in the clutch. pedal is released, plunger assembly rises as the fluid flows back into the master. when the plunger hits the top the bottom pulls away from the reservoir port and the fluid equalizes there. magic is finished, gears were shifted etc.

sooner or later something goes wrong and air goes down the reservoir tube, (the one we check monthly) and since air is destined to reign above fluids it gets trapped at the top. actually it's in the same space the spring occupies, the cylinder seal is right above the spring. no amount of bleeding or cussing will get that air out as things are now.

we've all seen the videos of taking the master out and inverting it so the air will rise to what is now the bottom of the tube where the reservoir port is. works great, and is a lot of work.

Hmmmm, remember I said those tubes swivel, and wayyyy back in my memory banks I recall someone saying to just pull the master out of the firewall and flip it upside down!!! with the reservoir port now at the top the air exits, rattle the lines a bit to dislodge bubbles, try reverse bleeding now, your method may vary, etc etc

the plastic clip that holds the rod to the pedal can be removed intact

all comments welcome, if I disagree I'll simple ignore you,,,

I'll try it tomorrow, when it's supposed to be a nice warm 20 degrees.

Ok. Mind if I jump in here? I'll be installing a new system tomorrow.

I bought a prefilled master/ slave system. I hung the master and hoses up in the shop before I quit today. It's hanging by the reservoir with the master inverted so any air bubbles should float to the top (reservoir) tonight. Will I still need to bleed the system after installation? Does connecting the tube to the slave introduce a significant amount of air?

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I installed a pre bled system 6-7 years ago. not much if any air gets in when the lines are connected. I would do a gravity bleed from the slave to be certain. the reservoir does not hold much.

that master I played with had a rock solid feel, so no air got in when I pulled it out last summer.
I reassembled it, and bled it to where the rod now moves less than 1/8".

Shran said:

There is a retaining clip inside the master cylinder piston that holds the pushrod in place and it's more or less permanent... which is why the instructions that come with new master cylinders say not to install it until you have to. I believe the snap ring you're looking at will allow the whole thing to come apart.

The one way valve is the quick connect fitting at the slave cylinder end of the hose. Bubbles rise during bench bleeding because of a) gravity and b) to a greater extent because fluid is being pushed past them and into the bottom of the hose. Eventually during bench bleeding, the piston will get so tight that you can barely move it - that's when you know you're done.

Click to expand...

I tried making a release tool, turned down a plastic tube to wrap around the rod and push down into the hole. couldn't get it thin enough without collapsing. maybe a piece of brass tubing would work to release the clip.



once the quick connect is connected fluid flows freely in both directions

yes you can invert the master and bleed it while still in the vehicle



must take the fender liner out, mine is a real pain to reinstall.

I had a discussion about this with a guy a few years back when he was dealing with a similar issue on his Ranger. I suggested going exactly this to him, and he responded by removing the plunger and filling the master through the resulting hole.

It still does not solve the issue caused by the U shape of the line.

adsm08 said:

I had a discussion about this with a guy a few years back when he was dealing with a similar issue on his Ranger. I suggested going exactly this to him, and he responded by removing the plunger and filling the master through the resulting hole.

It still does not solve the issue caused by the U shape of the line.

Click to expand...

true.

in a static state there is a clear path from the slave bleeder all the way to the open reservoir. a forceful injection of fluid at the slave bleeder should clear the lower line, and squirt like hell out of the reservoir. then invert & clear the master.

pulling the plunger and filling the cylinder??? yeah I love brake fluid on the floor too.

I was lucky, no air in the lower tube. clutch works good now with about 3/4" free at the bottom. not bad for 170,000 miles on it.

pjtoledo said:

pulling the plunger and filling the cylinder??? yeah I love brake fluid on the floor too.

Click to expand...

This guy was not the brightest crayon.

I have sigg'd him in the past with the quote "Did they pray? You have to pray before you use auto hubs."

pjtoledo said:

]

must take the fender liner out, mine is a real pain to reinstall.

Click to expand...

Wish I had seen this before trying to remove my old one. Couldn't get it out. So I removed the retaining ring and pulled the plunger from inside the cab so I could get the rest out in the engine bay. I didn't make too big of a mess. But I definitely do NOT recommend that method. New one goes in easy without that pushrod in it.

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yes you can remove the rod. 1/4" I. D. brass tubing cut into 2 pieces shoved down along the rod to release the clips. they go in about 1/2". hard to see, its 74mm from step to step.

That makes sense. Before assembling the new one, I saw the barbs down in the hole that catch the rod. I was a bit frazzled by then due to some family interruptions and the pressure of knowing I had to have the job done so I could drive to work Monday morning. Your simple solution didn't enter my mind.

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