AX-15, possible need for clutch flush?

Hey guys. A few days ago, I went to move my buddy's 99 sport, with the ax-15. I about slammed his clutch pedal through the floor! His was much easier than mine, and just felt so much smoother. Any ideas why so different? His mileage is probably around 170k, not sure on any replacement/flushes... I have also come to notice that lately (with mine) that starting from a dead stop has not been so smooth. If my revs are below 1500, its kind "jitters". Anything over that, its smooth.

I'm not sure what the condition of the current clutch is, but I feel safe making the assumption that I'm running the original clutch, with 124k on the clock. When should I start thinking about a new clutch?

The bigger question on my mind is flushing the clutch fluid. I have spent the last couple minutes searching, but I haven't come up with anything. The fluid has probably never been changed either, and probably wouldn't be a bad idea to just do that anyway. I was hoping to find a write up? Ill keep my eye out, and any advice/help on this would be great!

Thanks in advance!

do a good flush on the fluid. old fluid doesnt hold pressure as good as new fluid and can build up junk in it ruining seals and what not. im pretty sure there is an inspection plate somewhere under there. might be able to get a good idea of whats left on the clutch. if replacing the clutch get the flywheel resurfaced and get a good quality clutch. shell be good for another 200k.

IMHO If it aint broke, dont fix it.

I dont think flushing the master to slave cylinder is going to help much. (Fluid volume will remain the same. Hence would not change amount of pressure.)

More likely, you are noticing a difference in the spring tension.

I changed my master cylinder and noticed a difference in pressure. Its not huge difference. Dont overthink it!

A little clutch chatter happens with age and abuse. As long as the clutch doesn't slip, I wouldn't worry/fix it.


This is my Jeep. There are many others like it, but this one is mine. My jeep is my best friend. It is my life. I must master it as I must master my life. Without me, my jeep is useless. Without my jeep, I am useless.

I would not ordinarily worry about a clutch in the 124 k mile range if it's working all right. However, I should mention that the effort on my 99's clutch increased a good deal as the throwout bearing began eating its way through the diaphragm, before it explosively failed. That happened at about 240k, however.

I don't think a hydraulic change will help this. Keep an eye and ear on the clutch and I think as long as it isn't creaking, popping, or giving you throwout bearing noise, and as long as it's engaging at the right point, you're probably fine.

Unfortunately, there is no inspection plate. And unless your hydraulics have been changed, there's also no bleeder, so a complete fluid change will require either that you add a bleeder, disconnect the line, or take the whole hydraulic assembly out (it's installed as a unit) and dump it upside down, etc. As a partial measure, though, you could suck out the contents of the reservoir, replace, use a while, and repeat a couple of times. That would freshen it up some. The volume of fluid is small enough not to be too wasteful.

Oh, I just noticed that your handle says "96XJ." Here's another thing to check. The 99 has a different pedal linkage from yours. The 99 has a pin directly on the pedal arm to actuate the pushrod. The 96 has an earlier design with a welded on lever next to the pedal arm. My son's 96 developed bad clutch issues when the bracket bent owing to a poor weld. It made for high effort, and eventually ate the master cylinder bore up before failing completely. Make sure the pedal assembly is not going bad.

1. The brake fluid that is used in the clutch hydraulic system is just that--brake fluid. Brake fluid is extremely hygroscopic, which means that it ABSORBS moisture from the air. As the level of moisture increases in the brake fluid it becomes less effective.

2. YES, flushing the clutch hydraulic system should be a regular maintenance item, same as the brakes, and should be done at 30,000 miles or no longer than 3 year intervals.

The "shuddering" in the clutch has two probable sources: the flywheel surface has become glazed or possibly contaminated, or the Marcel spring has become fatigued--the Marcel spring looks like a cupcake liner that the bottom has been cut out of and then flattened, it is bonded to one disc and riveted to the other. The Marcel spring allows for some "give" during final engagement to reduce "shudders".

nothing like getting shot down my Joe P. (humble)

I HOPE no water is getting into the clutch line. XJ is not a submarine.

Anyway to change the fluid? I found none.

Not sure on the 96--on my 90 I siphon out the reservoir, fill with new fluid, then open the bleeder and run enough fluid through to flush the line, top off and done.

I dont believe the 90 xj had a AX-15. BA-10/5 ?

No bleeder on 96 or 99. (Maybe there should be?)
No maintenance schedule to change Clutch Fluid! FSM says replace entire assembly or top off. Dont over fill it!


The spring I was referring to is the one under the dashboard.


IMHO If you are worried about the clutch chatter, might as well replace the whole clutch. I have some at 111k. As long as there are no drastic changes, it aint worth fixing.

I have to apologize, I have a 97 XJ. I dont know where it says I have a 96?? Ill look into that...

Thanks for the replies. I really don't know much about the clutch system, but I completely agree with don't fix it if it isn't broke. I figured if a flush is as simple as something like bleeding brakes, then why not. I don't want to risk anything here, as this is my DD. It does work 100% ok, just seems like it could use some attention. I was really after some tips to ease the clutch, and reduce the shudder. Any other comments or suggestions, I'm all ears! Thanks again!

joe_peters said:

Not sure on the 96--on my 90 I siphon out the reservoir, fill with new fluid, then open the bleeder and run enough fluid through to flush the line, top off and done.

Click to expand...

No bleeder on the late system though there's a tapped hole in the slave for it. The hole is not drilled through to the cylinder. One could, of course, drill it through and then have a conventionally bled system, but it's not meant to be done.

4WDlifeform said:

I have to apologize, I have a 97 XJ. I dont know where it says I have a 96?? Ill look into that...

Thanks for the replies. I really don't know much about the clutch system, but I completely agree with don't fix it if it isn't broke. I figured if a flush is as simple as something like bleeding brakes, then why not. I don't want to risk anything here, as this is my DD. It does work 100% ok, just seems like it could use some attention. I was really after some tips to ease the clutch, and reduce the shudder. Any other comments or suggestions, I'm all ears! Thanks again!

Click to expand...

Ooops, I looked at the wrong post, from "clean96XJ." I suspect his is somewhere around a 96, and probably at least by someone's standards, clean. :laugh:

I'd try at least a reservoir fluid exchange, because it couldn't hurt. You might be able to get a bit more exchange if you have someone hold the pedal down while you suck the fluid out, but you must get some fluid back in before that person lets the pedal back up, to prevent sucking in air, so make sure they understand your signals.

Matthew Currie said:

No bleeder on the late system though there's a tapped hole in the slave for it. The hole is not drilled through to the cylinder. One could, of course, drill it through and then have a conventionally bled system, but it's not meant to be done.

Click to expand...

Maybe yes, and maybe no. You can purchase the late model MC and slave as a pre-filled assembly OR as separate components. When you purchase them separate you will have to drill the slave to bleed the system.

clean96XJ said:

I dont believe the 90 xj had a AX-15. BA-10/5 ?

No bleeder on 96 or 99. (Maybe there should be?)
No maintenance schedule to change Clutch Fluid! FSM says replace entire assembly or top off. Dont over fill it!


The spring I was referring to is the one under the dashboard.


IMHO If you are worried about the clutch chatter, might as well replace the whole clutch. I have some at 111k. As long as there are no drastic changes, it aint worth fixing.

Click to expand...

Post 3-9-89 production date ALL AX15s, no more Pukeots.

joe_peters said:

Maybe yes, and maybe no. You can purchase the late model MC and slave as a pre-filled assembly OR as separate components. When you purchase them separate you will have to drill the slave to bleed the system.

Click to expand...

Actually you don't have to. I had to get a new slave for my 99, and it is possible to do this without a bleeder. The Centrix one I got came with the procedure in the instructions. It's pretty clever. The cylinder comes with a plastic band cast into the plastic tip of the rod, to hold the piston in position before installation. To bleed it, you carefully unhook the retaining band, pull the slave piston out just far enough not to come out of the bore, fill it through the line connection hole before you connect the line, connect it, rehook the retainer, fill the reservoir, and then push it in all the way a couple of times. It should displace enough fluid to bleed itself and the line. Then install the slave. The first push of the pedal breaks the retainer off harmlessly. A dozen or so pumps of the pedal flushes the last air out, and you're good to go. This sounds odd but it actually worked.

Of course it probably would be easier in some ways to drill the thing and install a bleeder. The bleeder thread is a somewhat odd one, and I didn't happen to have a spare bleeder on hand, so I didn't bother to try it, since the prescribed method did the job.

How do you rebleed the thing if you replace the master cylinder? I don't have the plastic retainers on my slave now. Also, no bleed screw. 1995 XJ, may have been replaced prior to me.

You can still do it the same way, making sure not to pull the rod out too far when you bleed. It's just a little trickier to reinstall the slave and make sure the rod engages correctly. The plastic retainer is a convenience more than a necessity.