help diagnosing hydraulic clutch system :'81 to '85 Land Cruiser FJ40 FJ45 FJ60 OE parts (1 Viewer)

[sfab]

Hey all. I am trying to diagnose a clutch system that isn't pressurizing. This is a resto-mod scenario using OE equivalent 81-85 master and slave cylinder bought from reputable vendors. I have tried numerous bleed methods and attempts and am getting no pressure. Everything in the system is brand new (master, slave, throw out bearing, line, pressure plate and disc), except for the clutch fork and hub. All the new parts are spec'd for this application.

There are no leaks in the system. Everything I've read points to a bad piston seal in the slave and that masters are rarely at fault. Two things I have not tried but have read about are a pressure bleeder (pushes fluid through master to slave, vs vacuum that pulls fluid through slave from the master) and bleeding with the pedal to the floor during the entire bleed process.

Potential vectors though I can' see how: I have replaced the 10X1 fittings at both the master and slave with -3AN adapters with crush washers. The master cylinder fitting had a clearance issue, so I changed the 10x1 nipple to a banjo style fitting. The master is definitely pumping fluid through the system so it's not a blocked banjo port. I don't see how the line could be bad as its only way to fail is to leak.

Would love any thoughts. Thanks!!

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[charliemeyer007]

Just because stuff is new doesn't mean its good. If the seal is bad on the slave it leaks, so I think your issue is the master. Take it off and take it apart to see if you can find out what is wrong.

A new master isn't all that expensive, how is the connecting rubber hose?

Clutch Master Cylinder, 81-86 FJ4# BJ4# HJ47 FJ60 BJ60 HJ60

AISIN Clutch Master Cylinder Vehicles without clutch booster. 8/80-4/86 Toyota Land Cruiser FJ40, FJ43, FJ45, HJ47, BJ40, BJ42, BJ43, BJ45, BJ46 8/80-4/85 Toyota Land Cruiser FJ60 USA 8/80-11/84 To...

www.fjparts.com

 

[sfab]

Thx charliemyer007. Hose is high quality coated stainless braid, DOT rated. Earls I think. What would one look for in a master that has failed, even if it were off the truck?

 

[charliemeyer007]

When putting it together its easy enough to tear/gouge the seal or it could have been defective when made and had like a hairline fault. There isn't a lot of parts in the whole system, and the seals are the likely source for fail.

I bought a SS hose, master and slave off ebay for like $100 last fall, great investment.

 

[Pighead]

If no fluid is leaking out then the leak must be internal, and the little rubber cups do fail. Get a rebuild kit for each, take them apart and put them back together.
The problem will probably become obvious during the disassembly. It is a very simple system, I can usually just bleed by gravity, no pumping needed.

 

[sfab]

oh, nice! That sounds like a pretty simple fix. Thx pighead. I would spend more on a gauge and fittings to check pressure than that.