78 FJ40 - Clutch slave cylinder failure

[cmcmill01]

So, I was heading out for a drive, as it was a lovely sunny day. The clutch lost all resistance and didn't work. It's a bit scary, but it's all good. I managed to get it driven back to the house.

So the slave had lost all its oil and internal piston assembly, might still go and look for it!!

So, questions: Why did the slave extend itself so much that the oil and piston parts were lost? Will order the cylinder kit to replace the missing parts
The release fork wobbles about a good bit, is this normal and also the wear on the clutch disc? Do the pictures give any red flags on why the failure??

Thanks

 

[dazerb]

I just picked up this whole kit from CruiserMatt's Off-Road & Performance - https://cruisermatts.com/
Price and shipping were awesome. Can't speak to the fork...
Mine just intermittently fails with pedal to the floor, especially on cold mornings. A few pumps and it comes back, but I figure the bore is crappy in one or the other. Possible rust or water.
Clutch Slave/Clutch Master/Short brake hose in the pile.

 

[rlong]

Normally under load (clutch pedal pushed in) the fork / throughout bearing would be engaged against significant spring pressure way before the piston is coming out of cylinder. So the other option (the other end of the cycle) would be when not engaged (foot off pedal) your adjustment (TO Bearing to clutch release fingers) was too great and the push rod fell out of it’s recess in the fork, and the next time you pressed the pedal (once or twice) “POP” out the piston shot.

I’m just not sure where the pushrod was hanging when you found it! It is possible with a new slave, and correctly adjusted TO bearing to clutch space (more than 0.0”, more like an 1/8+/-.. there is a spec.) all will be good. It is also possible your clutch disk or cover are worn or failing allowing for excess “throw”. I’d assemble with new slave (or kit) and adjust to spec. I suspect your clutch pedal will feel different (less free play, engage earlier) I’d get someone to engage the clutch while you watch from below. Good Luck.

 

[cmcmill01]

I just picked up this whole kit from CruiserMatt's Off-Road & Performance - https://cruisermatts.com/
Price and shipping were awesome. Can't speak to the fork...
Mine just intermittently fails with pedal to the floor, especially on cold mornings. A few pumps and it comes back, but I figure the bore is crappy in one or the other. Possible rust or water.
Clutch Slave/Clutch Master/Short brake hose in the pile.

View attachment 3878383

Thanks, I have ordered some parts, but I think the master and slave are newish!!

Normally under load (clutch pedal pushed in) the fork / throughout bearing would be engaged against significant spring pressure way before the piston is coming out of cylinder. So the other option (the other end of the cycle) would be when not engaged (foot off pedal) your adjustment (TO Bearing to clutch release fingers) was too great and the push rod fell out of it’s recess in the fork, and the next time you pressed the pedal (once or twice) “POP” out the piston shot.

I’m just not sure where the pushrod was hanging when you found it! It is possible with a new slave, and correctly adjusted TO bearing to clutch space (more than 0.0”, more like an 1/8+/-.. there is a spec.) all will be good. It is also possible your clutch disk or cover are worn or failing allowing for excess “throw”. I’d assemble with new slave (or kit) and adjust to spec. I suspect your clutch pedal will feel different (less free play, engage earlier) I’d get someone to engage the clutch while you watch from below. Good Luck.

Cheers! Once I get the new parts, I will do this check. Yep the pushrod was hanging in the fork, and I couldn't find the piston part on the road!!

 

[cmcmill01]

Update:
I got the new Clutch Slave cylinder kit and was bleeding the system with my son on the pedal when the following happened. It pushed the rod through the hole in the release fork. This explains what happened when I was driving. The push rod was in the release fork, but the piston was nowhere to be seen.

Based on the pictures below, do I need a new release fork? Can these be changed in situ?
Is the push rod nut the correct size of does it look small?
Also, below, you can see that one of the retaining pins seemed to fall out. Is it a RELEASE BEARING HUB pin? Can this be refitted in situ?
Do you think there is an issue with the clutch cover that prevents the clutch release bearing from pushing in?

On the final picture, there doesn't seem to be any clutch spring in place for it?

Thanks

 

[charliemeyer007]

Your fitting and lock nuts are on the wrong side of the clutch fork. Black glue isn't going to hold it.

 

[cmcmill01]

Your fitting and lock nuts are on the wrong side of the clutch fork. Black glue isn't going to hold it.

I know, when the clutch was pressed, it pushed the lock nuts through the hole in the clutch fork!

 

[charliemeyer007]

Well, I would just put a washer over the cone nut that doesn't push threw. Or a big one between the cone nut and lock nut. I have never seen a fork with a wore out hole. It could easily be welded with a washer on the back side

 

[Pighead]

I would get a bigger acorn nut. I'm pretty sure that you can't change clutch forks without pulling the tranny back some. That is the throwout bearing hub clip. The lower one is not hard to replace, the top one is...

 

[cmcmill01]

I would get a bigger acorn nut. I'm pretty sure that you can't change clutch forks without pulling the tranny back some. That is the throwout bearing hub clip. The lower one is not hard to replace, the top one is...

Thanks, if you look at one of the first pictures, the lower bearing hub clip is still in place, so need to figure out how to do the upper!
Really don't want to start into the tranny, that looks above my skill level!!

 

[pb4ugo]

With some time and patience you should be able to get that clip back in. At the end of the fork there's s hole for the return spring and a little bracket at the slave with a hole.

 

[Pighead]

Might look like this

 

[cruisermatt]

The reason you are getting a lot of movement with that throwout hub is that it is not the correct one. It should not have numbers stamped on it. That is from some random vehicle. Your master cylinder is also not correct.
As is your pushrod on the slave cylinder. Too small OR the hole in thefork is worn out, possibly both. I would do all of these + a throwout bearing (we also have these, just no on the webstore). Drop the transmission, replace all this, and you will have nice smooth quiet system that will last you decades.

New OEM Clutch Fork Parts Kit 1975-1985 2F

Fits: 1975-1984 2F Includes new clutch fork, clutch fork boot, throw-out hub, throw-out hub clips. All parts are new genuine Toyota. For slave cylinder bolts and return spring, see: Clutch Slave Hardware Kit If you have any questions about compatibility or installation, please do not hesitate...

cruisermatts.com

Reproduction 31238-60041 Clutch Fork Return Spring Tab

Reproduction of the clutch fork return spring mounting tab found on 1975-1984 Land Cruisers, no longer available from Toyota. Shipped flat and can be hand-bent for use on either right or left-side applications. Available in mild steel or stainless. See drop-down to select material. OEM Bolts...

cruisermatts.com

Clutch Slave/Release Cylinder OEM Hardware Kit 1975-1984

Includes: Spring - 90506-16475 Bolt, x2 - 91611-41055 / 91611-61055 OEM Toyota parts! If you have any questions about compatibility or installation, please do not hesitate to reach out to us for assistance! We're here to make sure you get the right part!

cruisermatts.com

Clutch Master Cylinder 1975-1980 Land Cruiser

Aisin (OEM) made replacement clutch master cylinder for 1975-1980 model year Land Cruisers FJ40, FJ43, FJ45, FJ55, as well as diesels, please inquire if you have any questions about fitment. Will also work as a replacement for NLA earlier years with minor changes to the fluid line. Please email...

cruisermatts.com

Clutch Slave Cylinder 1975-1980 Land Cruiser

Aisin (OEM) made replacement clutch slave cylinder for 1975-1980 model year Land Cruisers with 2F engine, FJ40, FJ43, FJ45, FJ55. OEM Part # 31470-60071 Be sure to also check out: Return Spring Tab Mounting Bolts and Spring If you have any questions about compatibility or installation, please do...

cruisermatts.com

 

[cmcmill01]

With some time and patience you should be able to get that clip back in. At the end of the fork there's s hole for the return spring and a little bracket at the slave with a hole.

Thanks will give it a try!!

Might look like this

View attachment 3890286

Cheers, mine kind of looked like that, will look for a larger Acorn

The reason you are getting a lot of movement with that throwout hub is that it is not the correct one. It should not have numbers stamped on it. That is from some random vehicle. Your master cylinder is also not correct.
As is your pushrod on the slave cylinder. Too small OR the hole in thefork is worn out, possibly both. I would do all of these + a throwout bearing (we also have these, just no on the webstore). Drop the transmission, replace all this, and you will have nice smooth quiet system that will last you decades.

New OEM Clutch Fork Parts Kit 1975-1985 2F

Fits: 1975-1984 2F Includes new clutch fork, clutch fork boot, throw-out hub, throw-out hub clips. All parts are new genuine Toyota. For slave cylinder bolts and return spring, see: Clutch Slave Hardware Kit If you have any questions about compatibility or installation, please do not hesitate...

cruisermatts.com

Reproduction 31238-60041 Clutch Fork Return Spring Tab

Reproduction of the clutch fork return spring mounting tab found on 1975-1984 Land Cruisers, no longer available from Toyota. Shipped flat and can be hand-bent for use on either right or left-side applications. Available in mild steel or stainless. See drop-down to select material. OEM Bolts...

cruisermatts.com

Clutch Slave/Release Cylinder OEM Hardware Kit 1975-1984

Includes: Spring - 90506-16475 Bolt, x2 - 91611-41055 / 91611-61055 OEM Toyota parts! If you have any questions about compatibility or installation, please do not hesitate to reach out to us for assistance! We're here to make sure you get the right part!

cruisermatts.com

Clutch Master Cylinder 1975-1980 Land Cruiser

Aisin (OEM) made replacement clutch master cylinder for 1975-1980 model year Land Cruisers FJ40, FJ43, FJ45, FJ55, as well as diesels, please inquire if you have any questions about fitment. Will also work as a replacement for NLA earlier years with minor changes to the fluid line. Please email...

cruisermatts.com

Clutch Slave Cylinder 1975-1980 Land Cruiser

Aisin (OEM) made replacement clutch slave cylinder for 1975-1980 model year Land Cruisers with 2F engine, FJ40, FJ43, FJ45, FJ55. OEM Part # 31470-60071 Be sure to also check out: Return Spring Tab Mounting Bolts and Spring If you have any questions about compatibility or installation, please do...

cruisermatts.com

Agree on the overall, but heading into summer and car shows, that's sounds and reading about it is a big job and dont want to miss the fun!
The Slave is Aisin, not sure on the master.

 

[cruisermatt]

You could do this in one day if you started early, even if you never have before.

Your master cylinder is 100% not a Land Cruiser part.

 

[cmcmill01]

You could do this in one day if you started early, even if you never have before.

Your master cylinder is 100% not a Land Cruiser part.

Will have a look at the above parts, feel I might as well change the clutch when I'm in there, as I take it the clutch fork cant be changed in situ??

 

[cruisermatt]

Will have a look at the above parts, feel I might as well change the clutch when I'm in there, as I take it the clutch fork cant be changed in situ??

That’s correct. We have genuine clutch kits and rear main seals in stock as well.

 

[anothernz45]

Have had a clutch fork punch thru like yours, bolt a cap screw thru the hole and die grind or dremel the allen hex bigger if needed until the pushrod on your slave fits nicely. They are much harder than the Toyota fork - has been there well over 10 years and both ends still look good.

 

[cmcmill01]

Have had a clutch fork punch thru like yours, bolt a cap screw thru the hole and die grind or dremel the allen hex bigger if needed until the pushrod on your slave fits nicely. They are much harder than the Toyota fork - has been there well over 10 years and both ends still look good.

Thanks, wouldn't have a picture of what you did?

 

[anothernz45]

You will have a 5/16 hole punched thru the fork, get a 5/16 or 8mm allen head capscrew then grind head down so most of the hex is gone and use a ball head in a die grinder to form a little depression for the pushrod on your clutch slave to locate in. My fork had slogged out enough that I could pull the capscrew into it with its nut but you may have to enlarge the hole slightly. This temporary fix has ended up remaining there even after a clutch job.
Thats oil on the slave, not fluid - my breather just hangs down the side of the block now. I look on it as rust prevention.