Toyota clutch master cyl bleeding

[nick c]

I give up, I posted on Pirate and I'm posting here. Need some help figuring this out.

It's Tuesday so I'm taking my chances, need pointers on getting my clutch master cylinder bled. Apologies for the long post, but wanted to get as many details as what I've tried out there.

85 4runner, 22re/5speed

Pedal has been soft,and my firewall paint inside the cab was peeling. Figured my master cyl was leaking (being low on fluid was also a tip). Picked up a new master and slave, installed them and had a friend help me bleed the system.

I did bench bleed the master.

using traditional techniques of him pumping the pedal while I was at the bleeder didn't work. I didn't get any fluid.

So I tried my POS 1 man bleeder kit from Harbor Frieght, it didn't work. So I borrowed a friend's, MightyVac. Still nothing.

I tried letting it gravity bleed for a few days since I didn't have time to screw with it during the work week. That didn't work.

So I started pulling fittings apart and seeing where I could get suction with the MightyVac, and where it was falling off.

If I had the MightyVac on the slave bleeder, I didn't get suction past the rubber hose at the frame/firewall connection. So I replaced the rubber hose with a new one from RockAuto.

Still can't get it too bleed, but now when I put the mightyvac on the slave bleeder, and undo the fitting at the Master Cyl, I get suction all the way up. And I did manage to pull some fluid through the line when I did that test. So I put it all back together and tried again.

Still nothing, this time I would pump the mighty vac and let it hold around 20 psi of suction (it would slowly leak down over a minute or so), but I'd continue to pump. Did that for about 15 minutes to maintain 20 psi of suction and didn't get a drop of fluid.

Also, when I had the line disconnected from the Master Cyl, I had my wife pump the pedal with my finger over the hole in the master. It had pressure as it pushed fluid past my finger.


I also tried putting a block on the pedal to hold it to the floor while I pumped on the mighty vac.

And for reference I have the adjuster on the pedal/rod set to about 1/4" till the end of the rod.

Any advice, pointers, am I just that big of an idiot?

I've bled plenty of brakes with out issue, and 1 or 2 other clutch masters, but this one has me beat.

 

[WA-Wheeler]

Perhaps faulty master or slave? Sucks to hear but it has happened to me before.

 

[WHITE TRASH1]

Open up the slave and see if there is a blockage.

 

[nick c]

I've pulled the bleeder, and blown through the slave, and didn't get debris out the hole where the hardline threads in. Or do you mean actually pull the piston out?

 

[deerlick]

pump it and don't stop and don't open the bleeder, keep pumping until you think ur leg will fall off and then keep pumping.

 

[ain'tstuckjustresting]

I'd say you got a bad master cyl. Last one I got from Oreillys was **** right out of the box. Casey and I bled and bled some more but never got a good pedal. Had only changed it because we put a new clutch in and figured what the hell. Ended up putting the old muddy one back on w/o any issue.

 

[WHITE TRASH1]

I've pulled the bleeder, and blown through the slave, and didn't get debris out the hole where the hardline threads in. Or do you mean actually pull the piston out?

Yup I'd pull it apart just for piece of mind and to lube the seal. Then do as ain't stuck suggests and pump the **** out of it. :redneck:

 

[nick c]

Well I pulled the slave apart, lubed the seal up with DOT 3 fluid, then filled it full of fluid and put it back it.

At the same time I pulled the pin out of the pedal/master cyl assembly. Was able to bleed it once I did that.

So new question...

I have a centerforce clutch, don't remember the exact model but I believe its whatever model Mike recommends. Pretty sure when I bought this clutch (it was originally installed on the Larry-Mobile Buggy several years ago) I asked Mike what clutch to buy. It never got much use since the buggy only saw a dozen runs so when I swapped motors I also swapped in the clutch.


The pedal is nice and firm but engagement happens right at the top of the stroke and its all or nothing, no feathering. And then the rest of the pedal stroke is solid but doesn't have any effect. So on the opposite side, when I'm releasing the pedal its out of gear all the way to the very end and then its 100% locked in.

Is there a way to adjust this? Or is this normal for Centerforce Clutch Packs? What does the adjustment on the pedal/master cyl do?

 

[pokey]

Pretty much the norm for cf clutches nick. Just takes a bit to get used to.

 

[WHITE TRASH1]

The adjustment on the pedal only changes the pedal location. If the pedal is too low it may not disengage the clutch, if it's too high it could force the slave cylinder to blow apart from pushing too much fluid.



I have had great luck making my own adjustable slave rod. I use an 8mm bolt meant for holding a toyota a/c compressor on it's bracket since it has a long shoulder and an inch or so of 8x1.25mm thread. Using a long 8mm nut used on the e brake adjuster for all toyota trucks with one end welded shut in a dome then sanded smooth. And a thin 8mm nut used on the throttle cable as a jam nut I assemble it all next too the factory rod cut to length with the long nut adjusted in the middle so I can go either way as needed.


It sounds like a complicated setup but it kicks ass being able to adjust exactly where the pedal engages and disengages.