How to change and bleed a clutch slave cylinder

joshisurdaddy · 01-24-2008, 12:40 AM

I must have read through a 100 posts that all contradicted each other about slave cylinders. Most said the clutch hydraulic system was a sealed system that must be replaced as a unit and cannot be bled. Funny thing is I bought a slave cylinder at autozone, Part # LSC309 for $55.99. You don't need to spend about $200 on an entire system. Why change the master cylinder and line if you don't need to?

NOTE: Leave the stupid bleeder screw alone on your new slave cylinder, it is worthless. Keep it closed.

Here's what you need to do:

1. On the left side of the transmission locate the slave cylinder and remove the two 13mm (1/2") nuts.
2. Take the bad slave cylinder out of the transmission.
3. Remove the roll pin out of the slave cylinder (the small round hollow pin in the slave cylinder near where the line enters it). Just find something about the same size and beat it out, I broke the end off of a file at squeezed it out with pliers but I'm sure a nail or anything the right size would work.
4. Attach line to new slave cylinder and re-insert the roll pin. Again pliers work great. If you stretched out the roll pin just re-squeeze it with pliers or a hammer.
5. Remove cap from clutch master cylinder (make sure to remove the plastic liner from the master cylinder if it is unattached from the cap, THIS STEP IS IMPORTANT TRUST ME!)
6. Fill the master cylinder with dot-3 brake fluid about half way.
7. Slowly manually pump the slave cylinder by hand until you no longer see bubbles coming out of the master cylinder. (Be sure to keep enough fluid in the master cylinder so you don't suck air back down) It only took me about 20 pumps to get all the air out. Yours may take more or less.
8. Once the air is out put everything back together and check your clutch, you should now be done.

If you have any questions PM me. I don't know how much time I spent reading posts with wrong info, that's why I posted this, I couldn't get a straight answer from searching so hopefully someone does a search some day and doesn't waste all the time I did. My TJ is a 98. I can't promise yours is the same as mine but I bet it is. If your not sure go to autozone.com and see if they sell a slave cylinder for your jeep. If it's the same part number then you CAN change your slave cylinder and bleed it.

**TheBoogieman** · 01-24-2008, 03:38 AM

I bought one for my 98' and it came as the entire unit (master/slave)together sealed with fluid already in it for $100.When you depress the clutch pedal it opens the system.

joshisurdaddy · 01-24-2008, 08:42 PM

Where in the world did you find it for $100? Depressing the clutch won't bleed the slave cylinder or the line...You MUST pump the slave cylinder to force the air up and out.

dkirkv · 02-12-2008, 07:24 PM

Hey - just tried the autozone slave cylinder replacement procedure on my '01 TJ 4.0L that was posted here, and it didnt work for me. First I had no luck getting the new slave installed on the line before the fluid drained from my master, so I had to start from a dry system, not sure if this is important. But I have pumped the slave to the point where only a stream of fluid comes up at the master, no air bubbles. Yet i have no clutch whatsoever, its worse than before I replaced it. Is there another trick I am missing? Also - how can you know if your master was good? Could it be I have a bad master cylinder as well? I am very frustrated with this thing. Any tips are appreciated.

mfw1fan24 · 03-13-2008, 07:41 PM

Any luck bleeding that slave I am having the same problems with my 99
PM me any info
Thanks

jbone302 · 03-27-2008, 09:46 AM

I am having the same problem I have blead the system and still have no clutch

Wif · 03-27-2008, 11:34 AM

Quote:

Originally Posted by jbone302

I am having the same problem I have blead the system and still have no clutch

Then if you bled it correctly (and the slave is moving correctly) you have an internal issue with the clutch itself

**TheBoogieman** · 03-27-2008, 11:49 AM

Quote:

Originally Posted by joshisurdaddy

Where in the world did you find it for $100? Depressing the clutch won't bleed the slave cylinder or the line...You MUST pump the slave cylinder to force the air up and out.

I didn't say bleed it,I said it opens the sealed unit up after installation.Like poking a hole in the aluminum top of your gas treatment bottle to get the stuff out.

fish4life · 05-06-2008, 07:17 PM

interesting thread i found thanks to the search. So what's the deal with the clutch hydraulic system being considered SEALED ... even by the FSM, yet people obviously are able to replace just one part of it (slave).

I've got a leaky slave as well, thinking about doing this myself...

95jeepgrl · 08-05-2008, 01:38 PM

holy crap do you know how long it took me to find this information!thank you for posting it!!! granted i have a 95 wrangler (yj) but this is xactly what i needed - could not figure out why system would not bleed - b/c the whole stupid bleed valve is a farse

)....................

to joshisurdaddy

Bill_Dunnigan · 08-05-2008, 02:18 PM

i just made my own slave cylinder from a bimba air cylinder (3/4" bore, 2" stroke, nose mounted, double acting) you can get this cylinder or one like it from Mcmaster.com and it costs $18. Only catch is you have to use 5.1 DOT brake fluid so it doesn't eat the seals. using this cyclinder make the system truely bleedable and much much stronger than the stock plastic slave. (bimbas are Stainless steel cylinders). over all it took me about 3 hours to replace because i reused the metal flange mount from the stock slave and had to find washers that fit. (one trip to the hardware store) the whole fix cost me $40 and its better than any replacement out there. i have been running it for over a year with zero issues and alot more confidence when i drive over things that can possibly snag it and rip it out. that is how i broke the stock one....lol stupid thorn bushes.lol

Luv2Race · 08-06-2008, 08:13 PM

I had to replace the slave cylinder on my 98. The new unit comes ready to use. all you do is put in the new on and like the post said previously it opens the system up, you do not have to bleed the new ones. Once I put the new one on my problem was solved. Good Luck!

pathfinder7 · 08-08-2008, 07:34 PM

What symptoms were you experiencing with the failing slave or master cylinders

pathfinder7 · 09-02-2008, 06:25 PM

Do you have the part numbers for the bimba

**NH2112** · 09-02-2008, 06:52 PM

Quote:

Originally Posted by joshisurdaddy

7. Slowly manually pump the slave cylinder by hand until you no longer see bubbles coming out of the master cylinder. (Be sure to keep enough fluid in the master cylinder so you don't suck air back down) It only took me about 20 pumps to get all the air out. Yours may take more or less.

Great write-up, I wish I'd had this to read about 6 or 7 years ago when I couldn't get my K10's clutch bled. After a few hours of frustration I just happened to press on the release fork a few times and felt it stiffen up. I said "No effin' way!" & checked the pedal; sure as hell it was nice & high. I got back underneath and gave the fork another couple dozen pumps for good measure, and accomplished in about 5 minutes what enough pumping to give me ACL problems in my left leg wasn't able to do.