Clutch Fluid Leak!!!

[chuckost]

I thought I was pretty good at diagnosing issues with my FJ40 after all these years, but I'm stuck!

Losing clutch fluid at firewall inside cab. Clutch master cylinder about 5-6 years old starts leaking. No other leaks hoses or slave. I rebuilt myself (honed), and it lasted about 200 miles. Bought 2 rebuilts, both lasted 50-100 miles. All adjustments & bleeding done each time. Looking at where the pushrod leaves the cylinder, it moves vertically up and down with stroke but I seem to remember they do have an up and down movement. Clutch works great after refill and bleeding, but after fluid all leaks out it stops working! What a surprise!!

Any ideas folks??

 

[Fast Eddy]

I don't think there should be any up-down movement. That would ruin the seals within 50-200 miles.

Mine leaks a little into the cab too, but I'm pretty sure it's 35 years old.

 

[chuckost]

The pushrod seems to have a round head that fits into a socket that allows play just inside the cylinder. Held in place be c clip. I agree with you though. Wish I would have paid more attention to the stock unit.

 

[Fast Eddy]

Yea, but if it's pushing up and down it will torque on the seal. Maybe the bracket where it attaches to the pedal is not allowing it to pivot as it should? Rusted? Needs lube?

I forgot to recommend a new Toyota part. Cruiser Dan at American Toyota in Albuquerque NM will give you a great price and quick shipping.

 

[miker]

The pushrod seems to have a round head that fits into a socket that allows play just inside the cylinder. Held in place be c clip.

What you describe sounds correct.

If you are not changing the slave as well as the master, you could be contaminating the master with old brake fluid that's in the slave. It may contain bits and pieces of debris, rust, etc. I would try to replace or rebuild both at the same time.

Also, some rebuilt units are junk and come with pitted or rough bores that quickly wear out the new seals and cause premature leaking.

The best bet for a long lasting clutch is to replace or rebuild both the master and slave. Also flush or replace any hard line/hose.

Also, you generally can't go wrong with OEM replacements if you are willing to pay the price. Sometimes its cheaper in the long run.