Thrust/Release Bearing replacement

tonycrd · **Posted:** Mon Feb 18, 2008 8:43 am

Maybe because you fiddeld to much with the slave-cylinder it now leaks?

And you are a real trooper, gosh, lifting the gearbox out and IN by hand laying on your back... :wink:

daxiet · **Posted:** Mon Feb 18, 2008 8:53 am

Thanks, I am going to try filling the resevoir and then pumping from the slave to release air. If after this it still stops working, then I will whip out my heavy credit card and shop for a new system. But there will be tears before that!

gmctd · **Posted:** Mon Feb 18, 2008 11:41 am

The leak is internal, bypassing across the cups, so, no you wouldn't see any external evidence - not much use replacing either cylinder without replacing the other, also - pull them apart for an up-close and personal inspection - they're simple t-plastic moldings with ss tubing insert to handle the pressure, aluminum pistons, no intricate valving to be concerned with - as mentioned, sometimes just cleaning the disgusting sludge cures the leak - can be done in the sink with hot soapy water - brake fluid is just alchohol-based fluid, similar to anti-freeze in 'feel', absorbs H2O so washes right off and away

NOTE: PROCEED WITH EXTREME CAUTION !!: do not let the significant other catch you using her sink to do the deed!

daxiet · **Posted:** Mon Feb 18, 2008 3:29 pm

Thanks gmctd, you have been most helpful.

I have just come inside after taking my Jeep for a lengthy spin around town. Took it on the highway to see if there were any vibrations (playing with driveshafts when removing gearbox). The clutch feels like a new creature, the gears are so easy and smooth, pulling away from stop streets is so much easier than it has ever been on this KJ. Always was jerky and sticky, the clutch that is.

So now let me explain how I got to go driving around town. Pure frustration lead to my success (however still in the balance), after trying to "bleed' the system yet again after toping up the resevoir and having zero success I opened the master cylinder and removed the little rubber thing inside. Then proceeded to pump the clutch pedal, then tried the gears and Bob's your aunty, the were working 100%. Put the little rubber thing back in, closed up the hatch and tried the gears which then stopped working.

To cut to the conclusion, it seems the rubber thing seals the fluid from the rest of the world, the rubber things center is able to breath air through a small hole in the top of the resevoir, thus its center is dirty. I take it this is to allow for expansion and contraction as the fluid in the resevoir heats up. None the less, I took a syringe and drain the fluid level down to almost 1/4 of the hight of the resevoir. Then tested, inserted the rubber thing and closed the lid. That is when I went for the test drive. When I turned the KJ off before putting it to sleep and then started it the clutch wasn't disengaging properly again. Opened the master took a smidge more liquid out (quite hot after driving around) and it was restored to former glory again.

From this I conclude, that if the resevoir is over filled the clutch doesn't function properly.

Why did it become over filled in the first place, well the release bearing I suspect was dead already when I bought the KJ, I gather the level on the clutch fluid was checked and adjusted accordingly with the wear of the clutch plate and the bearing (which ended up 1/4 if not more shorter than it should be). When I replaced the bearing, the excess fluid was pushed back into the resevoir, so began my issue.

For now this doesn't make 100% sense to me, but I can drive my KJ again. It is even quiter than before.

The fluid in the resevoir is very dirty, so if I do have relapses on the clutch disengaging I will take your advice and dismantle the hydraulics.

Thanks again.

daxiet · **Posted:** Tue Feb 19, 2008 3:15 am

Ok, my celebrations have been cut short. This morning the clutch is not disengaging again.

Now I am tire of playing with it, so gmctd, you recommend taking it to pieces and cleaning it? I think there may be dirty in it, when pushing the slave cylinder in and out yesterday a lot of junk got pushed out into the resevoir.

Will I be able to refill and get the air out once I have dismantled the system? How difficult is the routing of the hydraulic pipe?

Or should I first just try removing the the slave cylinder from the pipe, flushing fluid straight through, then cleaning the slave, then attempting to refill and bleed by pumping the slave cylinder?

Thanks

tonycrd · **Posted:** Tue Feb 19, 2008 7:36 am

I think that last idea would be best and less trouble.

daxiet · **Posted:** Tue Feb 19, 2008 9:42 am

Yup, I have been searching the internet high and low for solutions. The cost of a new system in RSA is R2632.00 about R2600, more than care to spend on my KJ (the thing is leeching my cash).

Tony, I agree after much reading, I will tonight remove the split pin which I suspect is holding the pipe in the slave cylinder, I will then pump fresh DOT4 not DOT3 through the system until I have clean fluid gushing out the bottom. I will then compress the slave to squeeze out its nasty junk, then suck new fluid in, shake it all about, do the... back on track, then push the new fluid out again, then try fill it as much as possible. After all this with brake fluid dripping from my clothes and running out my garage I will commence the primative bleed procedure. Then for hopefully the last time I will insert the slave, bolt it in and go wizzing around town!

I think I being too optimistic, probably a better bet is, I will be wizzing down to the stealership for a new hydraulic clutch system.

But all will revealed in about 5 hrs time, at 5pm local time I will leave JHB and cruise home ~150kms which if I am lucky will take 2hrs, but I count more on 2h30m (traffic getting out of the city is a ...). I have been on training for the past week and a bit, it hasn't helped having the KJ break at this point in time, leaves me with little or no time to get down and dirty with it.

Once fixed the debate remains, do I sell this beast or do I keep it and hope it has finished with its issues.

tonycrd · **Posted:** Tue Feb 19, 2008 10:58 am

Sell it after all the trouble you've been through?

Hang in there, there will come a time when it will give you nothing but a big smile on your face (and lots of fun taking it ofroad)

gmctd · **Posted:** Tue Feb 19, 2008 12:29 pm

You really should pull both master and slave cylinder, disassemble them, scrub the cups and pistons and spring and cylinders and reservoir and the tubing with hot soapy water - dry - coat the dry clean cups\pistons\cylinders with fresh DOT3 brake fluid and reassemble,

a.) first filling the slave with fresh fluid, stand it vertically so little drips out - attach the tube and fill the master with fluid, assemble the piston into the filled master, some fluid will exit the tube - fill the reservoir with fresh fluid - attach the tube to the slave - clamp the master horizontally so you can observe\fill the reservoir, then slowly excercise the slave until all air quits bubbling in the reservoir - the system is bled at that point - all the fluid is in the extended slave, so the reservoir should be low, but not empty

-OR-

b.) assemble slave, master and tube with fresh brake fluid on pistons\cups\cylinders - clamp master horizontally, depress slave, fill reservoir, release slave - put cap on reservoir, depress slave, cap off, refill res, release slave, cap on, depress, refill, release, depress, fill, release, etc until no more air bubbles in reservoir - system is bled, do not refill reservoir after last bleed, as fluid in extended slave will fill reservoir as slave is installed - install on KJ as noted B4 - no valving in clutch system allows air to rise thru system to top

Should have no leak-by after cleanup - if so, replace both cylinders, using procedure "b.)" for pre-bleeding - new slave will have the retainer strap on the rod, making installation easier

Doing the procedure is easier than typing it...............

daxiet · **Posted:** Tue Feb 19, 2008 1:40 pm

Thanks Tony, I am very tempted to keep the KJ, what I will get on tradein just doesn't make financial sense, but we'll see. If I do trade in, I will probably get a newer 2.8CRD with some warranty and maintenance plan left in it.

gmctd, thanks, I was hoping you would come with some advice before I commenced the procedure. I will provide feedback shortly.

daxiet · **Posted:** Tue Feb 19, 2008 2:46 pm

Well, I have hit a road block.

How the hell do I remove the pipe from the slave cylinder. I removed the split pin, tried twisting, pulling, bitting (not quite), but close.

There is a boat load of junk in the system, I resorted to draining the master, refilling, pumping the slave, draining, refilling, etc. Now it is working (for the time being, probably when I go test it now it will not be working) but there were plenty white pieces of sludge in the liquid after the last set of pumps on the slave cylinder.

Am I supposed to be able to pull the fitting out the slave after removing the split pin, any insight would be greatly appreciated. This system needs a proper bleeding.

Thanks

gmctd · **Posted:** Tue Feb 19, 2008 6:23 pm

It has an o'ring seal that may be holding you back, but yeah, once the roll pin is out, the tube comes out - and that is one method of bleeding it, but doesn't get the scuzz out from behind the cups - BTW: that's the same stuff used on the Dodge Cummins, so been there, done that, a few................

daxiet · **Posted:** Wed Feb 20, 2008 4:06 am

Tried my outmost this morning to get the pipe out the slave (it has no interest in coming out). I think any more tugging will result in a leak that I won't be able to fix (if not already done).

I have started to remove the master from the firewall (going to be very difficult to get it free, brake lines run against it's mounting plate (jury is out as to whether I will manage to get it out without damaging the brake lines). None the less both bolts are off (if I can get them back on, I will be a seriously happy and lucky camper).

Plan A:
Pull the slave up from beneath the vehicle and try dismantle it and bleed straight out of it (no pipe removal). The re-assemble and hope for the best.
Plan B:
Pull the master out and the slave, then take them for a walk where I will strip them both, clean them and then re-assemble, fill, prime, and the try get them back in place (try is the operative word)

How I dismantle the slave is already a question on its own: Seems designed to be assembled not disembled. Any detail on this and the master stripping would be valuable.

MrMopar64 · **Posted:** Wed Feb 20, 2008 10:33 am

The KJ service manual states that the slave cylinder, lines, and master cylinder are serviced as one unit. They're not available separately and not designed to be taken apart. With that in mind, if you get the pipe out of the slave, it probably won't go back in and stay.

For bleeding, fill the reservoir until at the full mark. Make very slow and constant strokes up and down with the pedal to allow the air to purge out through the master. Also leaving the cap off overnight can help to allow the air to bleed up. If any of the components are not working you'll have to replace the whole assembly (mater cylinder, line, and slave cylinder). Ouch.

gmctd · **Posted:** Wed Feb 20, 2008 11:49 am

Look into the business end of the slave to see a steel retaining ring - it is of the 720deg-type, so you'll need to insert a small screwdriver under the cut-away end and unravel it like a spring - behind the ring is the end-stop - the piston is spring-loaded so you'll have that tension to contend with - I use the rod to hold the piston back - once the piston is out, wipe th scuzz outta the cylinder, clean the piston\seal\cup in hot soapy water, dry, lubricate the piston\seal\cup with fresh brake fluid, reassemble - same drill for the master cylinder, but the retaining clip has three crinks that fit into three slots around the groove perimeter - master piston is also spring-loaded.

Not much reason for the tube sticking in the cylinder-end once the retaining pin is out, unless they pressed-in a swedging insert from inside the cylinder to reinforce the blurb in the FSM about not serviceable separately - NAPA carries the same pieces from the same oem manufacturer with the same molding and part numbers on the pieces as separate components: master, slave, reservoir, tubing\hose\line - the roll pins are started in-place, needing only tube insertion and squeezing with a pliers to complete the assembly - 378bucks from DCJ assembled, 178bucks from NAPA - been there, done that

NAPA online p\n for show'n'tell - 350112 and 360085 should be similar

daxiet · **Posted:** Thu Feb 21, 2008 3:56 am

Definetly service-able.

I couldn't get the entire system out because DC routed it behind a huge wiring harness, the fuel filter and pipes, the brake lines, etc.

So after giving this up as a bad idea, I removed the steel clip with a screwdriver, press the clutch pedal until the internals popped out and the fluid flowed out.

Pushed a couple ML through the system, cleaned the slave. Filled the slave, forced the internals back in, "bleed" the system. It now sort of works.

It now changes gears, but the clutch starts taking very low down (air in the system for sure). Why is there air in the system still, well the pipe going into the slave now leaks by the o-ring. As I said to my wife, it won't work until I break something else. So now it is driveable, but alas I can't say reliable.

I have booked it in tomorrow for the hydraulic clutch kit to be replaced at a small fortune, I am tired of brake fluid, crap design of DC (engine bay routing,layout). These things are labour intensive.

DC have an issue with non-servicable parts: Universal Joints, Clutch assembly, I am sure there are more that I have yet to find.

gmctd · **Posted:** Thu Feb 21, 2008 12:07 pm

Ok - the FSM's\FPM's are drawn by semi-skilled chimpanzees in Liberia, so any illustration must be taken with a large banana daquiri, but the clutch control system is identical to the Dodge stuff, just different p\n's due to the length of the hydraulic line between the cyls, and the tubing between the reservoir and m\c

NAPA carries the Dodge parts, but no listing for the Jeep stuff, even tho the KJ gassers (patooie!) need that stuff for the manual trans versions.

So, the components are made by AP, and have the oem numbers cast into the plastic parts - if you can post those p\n's on your pieces, I can compare them to what NAPA carries for the '94'97, the '98-'02, and the '03-'06, and possibly you can order the parts from NAPA on-line

The earlier m\c number is on the engine side, the late m\c number is on the fender side

The slave number location is catch-as-catch-can, as the cylinder freely rotates in the attaching flange, but it is on the side at the line-in end.

Also, you can go on-line to dodgepartsdotcom or 1-800-731-1022 and possibly get the parts at discount - most all dealers can handle all the DCJ stuff, now, from DCJ intranet service\parts availability - KJ CRD p\n 52129184AB, with -182 and -183 listed for the other engines

Main reason for the NSS blurb is because techs will address the most visible symptom, which in this case would be leaking cylinder - real problem is, if that cylinder is leaking, the other cannot be far behind, so the return-complaint would need be addressed as warranty, since problem wasn't resolved the first time in the service bay - so, 'not serviced separately' is a warranty preventative consideration.

tonycrd · **Posted:** Thu Feb 21, 2008 12:11 pm

Darn...so close...yet so far. Sorry it didn't work out...at least you saved a bundle taking the gearbox of yourself

daxiet · **Posted:** Mon Feb 25, 2008 4:58 am

Yes, you do not know how this makes me feel. If I had just lined up the slave piston in the begining I would have been done and dusted. I even think after dismantling the slave I would have been done and dusted if not for the o-ring now leaking.

I went to DC, bought the new kit R2600.00, I got so tired of playing on the Jeep, so I have sent it in with the kit to be fixed. I am just hoping this is the end of the issues and that it will survive long enough to be traded in. I honestly have no trust in its reliability going forward, very unfortunate.

I have been offered an excellent trade in on a almost new 2.8CRD (2007 with 5000kms), but I just don't want to spend that much. So I will probably sell it for a major loss and buy a small little car, which will have cheaper parts. Would love to none the less trade it in with DC, let them get the dud and suffer a bit.

daxiet · **Posted:** Thu Mar 06, 2008 8:25 am

I think it is all resolved, the Hyraulic Clutch components were fine, turns out I should have had the pressure plate and clutch plate done at the same time. Pieces of the failed release bearing had gotton in by the pressure plate, occasionally these pieces would jam between the pressure plate and clutch plate. At this point the vehicle would not go into gear.

As someone said, expensive learning curve.

I would love to post all the info first hand here, but for those who would like to see pics and more detail check this link:
http://www.ausjeepoffroad.com/forum/sho ... hp?t=74968

It's driving nicely, turned out the labour to get the job done for me was minimal, should have rather paid to have it done, they would have insisted I change the necessary components.

Flywheel is a lot noiser after the clutch kit replacement. Dual Mass Flywheen = ZAR7000.00 (the prices of parts here is rediculous).

Oh, can't get the pilot bearing separately, you need to buy the flywheel, they come as a set (wow, some brainie dude must have thought that one up). The only manufacturer who is oblivious to replacing a pilot bearing when replacing the clutch.

Or you can translate ZAR7000.00 for a needle bearing (pilot).

Thrust/Release Bearing replacement

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