Clutch Bleeding is a Pain

New master/slave and no leaks in the hydro lines that I can see.

Bench bled (tipping master/slave cylinders at 45 degree angles to get air out pre installation) both cylinders and installed. Got it to bleed just enough to get me by and had to extend my clutch rod all the way out.

2 months later if found out the adjustment was a Bad move

Adjusting the clutch rod as far out as it could go broke the master cylinder rod (somehow) so I got another under warranty free of charge


Bench bled new master cylinder and installed. When the wife pressed down on the clutch to start the bleeding process a heard air escaping from the fluid line connecting to the master cylinder. I had cross threaded a bit and fixed it. Second time around starting the bleeding process the clutch smacks straight to the floor with 0 resistance.

After and hour of pump pump pump hold crack tighten (rinse repeat) still had 0 pressure. So I tried gravity bleeding.

Popped the cap off the master cylinder and cracked the bleed screw on the slave. Nothing. Not a drop.

Unthreaded the bleed screw completely off to see if I could get a dribble. Nothing comes out. Trucks been sitting out there for a few hours now with a full reservoir and no bleed screw on the slave and the fluid level hasn't dropped any.

Clogged line? Huge air pocket? Anyone have any ideas. I would give up and take it to a mechanic and have them power bleed it but wouldn't you know it, you can't drive without an operable clutch

 

Possibly bad master cylinder out of the box. I've had it happen.

 

What brand Master Cylinder did you get ??

Most of the China Built stuff is very poor quality.

I keep the Aisin parts sitting on the shelf for the day it needs changed.

 

Oreillys PowerTorque Master Cylinder. ~28$ for it.

You think it could really be a bad MC and not a clogged line or something that I'm missing?

 

Well do you think you knocked enough dirt into the line to cause it to be clogged ??

I bet bad Master cylinder out of the box.

 

Well first, the old MC had a black oily residue at the bottom of the reservoir which I thought was weird and couldn't be good for my lines. It definitely wasn't just DOT3 and I have no idea how itot in there.

When I put the second MC in, I held the outlet nozzle with paper towels to not let it leak all over the place.

Maybe paper towels got in there? Maybe that black oily residue messed something up?

Last night i hooked up one of my wife's syriges and tubing to the top hydro line that comes off the MC and opened the bleeder valve on the slave and ran fluid through the lines and it went through fine.

I'll throw another MC on it and see if that works

 

When I replaced the clutch's master cylinder on my 1987 Toyota truck, I just mounted the thing, poured in the fluid, and had the wife pump the clutch while I operated the bleed screw on the slave. Never had a problem. Go figger.

 

For what it is worth i only ever bench bled one Master Cylinder about 45 years ago .

No problems bleeding any of the numerous ones I installed over the years

 

Fixed.

Got a new MC and one of those vacuum bleeders.

Put the new MC in after the "bench bleed" and fluid was gravity feeding perfectly down to the slave.

Tightened everything up and bled the ol fashion way and it works beautifully.

Never would've guessed it was a bad MC out of the box. That's why I ask you pros. Thanks guys

 

I would've never suggested it unless it hasn't happened to me ahah. Glad you got it

 

I remember replacing the clutch slave cyl on a 1990 Nissan D21 pickup. I'm not sure about 1st gen Tacomas but that Nissan had a mid cylinder con the pass side pf the lower firewall called a damping cylinder. The only way to bleed it was to vacuum bleed it. I got a hand vacuum pump from an auto parts store for less than $20.