Quick repair for FJ40 clutch slave using available parts

[DougAustinTx]

This is my first post, and I thought I would share what I found today. My son's '77 FJ40 lost its clutch slave today. It was spraying fluid out the dust protector bellows when the pedal was depressed. After taking the slave off the passenger side, we found the piston was bottomed in its cylinder. Pushed it out with compressed air and found a slight ripple or crease in the cup (there was only one cup on the piston, although it looked like there was room for two). The wrinkle in the cup revealed a very small hole that was allowing the pressurized fluid to escape. We couldn't find a local replacement as he needed to drive the truck to work in a few hours. After running a brake hone with some WD40 down the cylinder bore and spraying out the residue with brake cleaner, the cylinder appeared to be in pretty good shape with no bad rusting, so we just needed a new rubber pressure cup for the piston. After measuring the bore of the original slave cylinder, we found it to be 13/16's. Went to Advance Auto and found a 1994 Toyota slave (Perfection Performance brand) part number 37525 for $12 IN STOCK at the store. Took the new piston out of that part and used some DOT3 to lube the old cylinder and new piston and installed it. The new piston had two pressure cups on it. We left the assist spring on the end of the new piston. Bolted the unit back in place and it sealed and worked just fine. I did have to adjust the linkage to provide more freeplay, which must have been caused by the new piston not being drilled as deeply for the adjusting rod as the original piston, as the pistons looked to be identical in overall length. Anyway, I'm sure it would have been better to replace the cylinder, but when you need to get your truck back on the road, and you don't have a factory replacement handy, this process will get it done in under an hour using a part that virtually every Advance Auto keeps in stock at each store.

 

[Eshu Elegua]

thanks for the inf. good to know a part number also...now post some pics of you 40..as you know we love pics....

 

[DougAustinTx]

thanks for the inf. good to know a part number also...now post some pics of you 40..as you know we love pics....

You're welcome. I haven't started on the restoration of my '79 FJ40 yet, so here it is in current condition. I plan to change the paint to Dune Beige and get some factory wheels. The best thing about it is that it already has saginaw/FJ60 power steering, and the driveline upgrade to a 5-speed and FJ60 transfer case and differential. The Vintage Air unit is waitng patiently in my garage.

 

[jmdaniel]

So, DougAustinTx, where you from?

Check out the local Austin group, in the Clubhouse section here. Lot of good folks.

 

[DougAustinTx]

I moved from San Antonio to Austin in the eary 70's. In the past, I mostly restored Chevy and Mopars, but my son and I both got into FJ40's recently. The engine in the 40's look like the old chevy straight 6, so they should be fairly easy to work on, but I have absolutely no familiarity with the drive system used in these trucks. When we get finished with my son's '77, then my '79 is going to get almost all the metal replaced except for the roof and rear floor. I'll check out the Austin group, thanks!.

 

[tubalubb]

I am going to resurrect this thread by posting some photos. This fix saved my bacon today. My six month old napa reman gave up the ghost out of the blue Saturday evening. Napa isn't open Sunday and none of the others could get a clutch slave cylinder for the 40. Stumbled on this thread through a google search. Oddly enough it was one of only two repair threads I could find on any car, everything else was replace. I typed in the part number Doug referenced on the autozone website. I think it changed. The numbers that came up for the part were 11887 and 44026 respectively, in stock $11.99. Ordered online and took my wife's car to the 40. I was a little concerned because I couldn't figure out how to remove the piston from the cylinder without messing it up. see how the piston fits perfectly in my 40's cylinder.
All I had was a small screwdriver so I pushed it through the line hole in the back and eventually the piston popped out enough for me to work it out without damage. I left the spring on the cylinder as Doug did, this helped because I think my initial problem was an acorn nut that was too small. Leaving the spring on forces you to adjust the nuts almost all the way to the bottom of the rod. I bolted it up and reattached my spring, opened the bleeder, poured fluid in the master and tightened the bleeder after mashing down the clutch a few times and filling the reservoir. Worked like a charm, sort of regretting overnighting the "real" slave cylinder because this one works so well. Thanks Doug Now back to my original problem thread...

 

[Howard705]

Nothing wrong with this fix-good one and good price. for years mechanics rebuilt all these parts including relining the shoes and replacing the rivets. I keep all the seals (transfer/trans/axle/hub/etc for a 40 earlier/later more or less. and all wheel cyl kits/caliper kits clutch slave/master kits shoes/pads- not counting extra cores of all these parts. they're cheap and will get you back on the road quick.

 

[sggoat]

That's a really good "fix" thread--something to be said for folks who have the "MacGiver" in them--
Good job--put this in my FJ-40 book.

 

[Avro]

This is my first post, and I thought I would share what I found today. My son's '77 FJ40 lost its clutch slave today. It was spraying fluid out the dust protector bellows when the pedal was depressed. After taking the slave off the passenger side, we found the piston was bottomed in its cylinder. Pushed it out with compressed air and found a slight ripple or crease in the cup (there was only one cup on the piston, although it looked like there was room for two). The wrinkle in the cup revealed a very small hole that was allowing the pressurized fluid to escape. We couldn't find a local replacement as he needed to drive the truck to work in a few hours. After running a brake hone with some WD40 down the cylinder bore and spraying out the residue with brake cleaner, the cylinder appeared to be in pretty good shape with no bad rusting, so we just needed a new rubber pressure cup for the piston. After measuring the bore of the original slave cylinder, we found it to be 13/16's. Went to Advance Auto and found a 1994 Toyota slave (Perfection Performance brand) part number 37525 for $12 IN STOCK at the store. Took the new piston out of that part and used some DOT3 to lube the old cylinder and new piston and installed it. The new piston had two pressure cups on it. We left the assist spring on the end of the new piston. Bolted the unit back in place and it sealed and worked just fine. I did have to adjust the linkage to provide more freeplay, which must have been caused by the new piston not being drilled as deeply for the adjusting rod as the original piston, as the pistons looked to be identical in overall length. Anyway, I'm sure it would have been better to replace the cylinder, but when you need to get your truck back on the road, and you don't have a factory replacement handy, this process will get it done in under an hour using a part that virtually every Advance Auto keeps in stock at each store.

 

[Avro]

Does the bellow have to be glued back on?

 

[bikersmurf]

The one thing I'd comment on... I've rebuilt a lot of calipers, master cylinders, and brake cylinders. I was taught to use Brake fluid to lube... WD40 (or other oils) should be avoided.

 

[My First FJ40]

I thought I'd revive an old thread with a bit of an update on pricing. The slave cylinder on my BJ (originally an FJ but one of the PO's dropped an old B series diesel) decided it no longer wanted to hold any fluid.

After finding this thread, I decided to pull it and rebuild it using the above part number (11887), but when i went to put it all back together, that piston is for a cylinder with a .81" diameter. My cylinder is .75, so after a quick google search for an appropriately sized piston, and a trip back to Das-Autozone, to swap out the new slave for 13090, got it all back together and it seems to be functioning as it should. Similar to comments made above, the new piston has 2 rubber cups to seal the fuild in. The cylinder doesn't fit as it is close on the mounting holes, but sits at an angle with respect to the rod orientation. However, I swapped the piston and the spring back into my slave cylinder after a quick cleaning with a green brillow pad and a drill.

Cliffs notes version:
Slave cylinder .75" diameter - Autozone part# 13090 - $14.99
Slave cylinder .81" diameter - Autozone part#11887 - $13.99