1990 jeep wrangler slave cylinder replacement

I searched for prior posts and didn't find a consensus on this.
Stock 88 256 with 44K miles. RE 4" lift 1000 miles ago on 33s.

My clutch pedal is going soft at an increasing rate. I could get 100 miles or so and have to top off the master cylinder a few months ago, now I'm lucky to get 20 miles around town before having to fill it up again and pump the clutch to get pressure back on the clutch pedal. Fluid is leaking out of the bell housing.

Y'all think its the internal slave? If not, what? Do you think lifting it and putting 33s on it caused it or is it just random & age?

Anyway if it is the internal slave what's the recommendation and why? Should I replace this with an OEM part, high quality aftermarket part or convert to external slave?

I'm interested in durabilty, complexity of work and price of parts and labor since I can't do this myself.

Also, know of a good shop around ATL?

Thanks!

I would convert to external, especially if you will be paying a shop to do it. It will be a large cost once, then you can do it yourself after that.

There are threads on here with external and internal failures after changing to a new slave, so the external would be an easier pill to swallow.

Having a shop do the labor, the labor cost should be the same or very close to the same. Either way the transmission has to come out. The kit, if bought new is around $500.00. You might be able to piece the necessary used parts together for a couple/few hundred dollars.

For the additional cost, I'd certainly go with the external clutch slave cylinder. One and done.
I suggest replacing the clutch while the transmission is out. It might not be necessary with 44K miles on the Jeep, the shop can advise you once the trans is out.

I doubt that lifting the Jeep and adding the larger tires had anything to do with the clutch slave cylinder failing.

Good Luck, L.M.

Thanks guys. @Luckymac what's the recommended external slave kit you mentioned?

Anyone know of a good shop in ATL?

Recently another poster used the Advanced Adapters kit and appeared to be happy with it. I'm sure the kit is offered by more than one retailer.
Check the reviews of the kit.

If I were planning on an external slave kit in the near future, I'd Google "external clutch slave kit" or something similar. EBAY has a whole bunch of used 4 cyl kits for cheap. You'll have to search some to find one for a 6 cyl. The 4 cyl kits and the 6 cyl kits aren't interchangeable.
Be sure to check the reviews of the seller if you buy one off EBAY.

I'm slowly rebuilding a 4.2 for when it's time to replace my current motor, so I hopefully have plenty of time. When I replace the motor, I'll switch to the external slave setup. I'm currently keeping my eyes opened for the necessary parts at a bargain price. I can always just order the Advanced Adapters kit if necessary.

If you closely examine the kit offered by AA, it includes the front transmission seal housing. The housing is different for internal and external slave setups. I don't see where the EBAY used kits include the external seal housing. I think your best bet is to spend the (+ or-) $500.00 for what's sure to be a complete kit. Either the AA kit or one from some other supplier.

Good Luck, L.M.

If you're not familiar with all the parts involved, Call the Vendor you are thinking of using and pick their service techs brain to make sure you get all the right stuff ordered the first time, If you can't get a knowledgeable guy on the phone I'd pick a different vendor. Ask about LUK clutch and slave parts, High satisfaction ratings from that brand. If I ever kill my BA/10 and go to an ax-15 I'm planning on using Advance Adapters, but Novak is another vendor you might want to check into.

Taylure, let's consider this from a financial standpoint. These are hard core Jeep enthusiasts giving you advice about your Jeep as if it were their own. I don't know your situation, for example: a new Jeep owner planning to join the cult, an owner that is serious about off-roading adventures, someone wanting to restore an old Jeep and keep it long term, or just something you thought you might like to drive until you buy your next vehicle. The swap from internal to external is far more expensive than just keeping it stock in it's original condition. If you insist that they use high quality parts, keeping it stock will last plenty long enough until you purchase another vehicle. Like I said, I/we don't know your situation, so maybe this will help you decide which way to go and save you money in the long run. Good Luck........

I agree with Krangler87's advice for the most part with one major exception....unless you can find a NOS (new, old stock) internal slave cylinder the external kit is the most practical.
The OE internal slave cylinder is no longer serviced by Jeep and it's reported that the aftermarket slave cylinders suffer from poor quality control. IE, they seem to prematurely fail. Sometimes as soon as they're installed or soon thereafter. Since replacing the internal slave cylinder requires pulling the transmission, any money saved by not doing the external kit is wiped out if the new cylinder fails even once. There's been reports on this forum of posters having to replace a new internal slave cylinder multiple times.

Even if the part is guaranteed, the parts company won't pay for the labor to replace it. Since finding a top quality internal slave cylinder is such a crapshoot, my heartfelt recommendation is go with the external kit.

Consider this, if it weren't an ongoing issue, why would Advanced Adapters or Novak go through the expense of putting together a kit? If the internal slave setup wasn't plagued with failure, nobody would buy the external kit.

Whichever way you go, let us know and how it works out for you.

Good Luck, L.M.

Hey guys,
Thanks for the honest opinions here. I'm in the "restore and old jeep" camp and reliability is my biggest concern. I'll hand the keys over to my 16 year old when the weather is nice on weekends and I don't want him stuck in the middle of the road with his girlfriend giving him the stinkeye.
We are definitely cost sensitive but I don't want to do this twice either.

Sounds like both the stock replacement and the conversion to external can be tricky. I'd love to find some shade-tree jeep mechanic who's made these repairs before so at least I can take the labor risk out of the equation.
@Krangler87 - appreciate the shop recommendation up 400. Is something like this right in their sweetspot? Or will they be watching the same youtube videos that I have? Looks like they do it all.

Hey guys,
Thanks for the honest opinions here. I'm in the "restore and old jeep" camp and reliability is my biggest concern. I'll hand the keys over to my 16 year old when the weather is nice on weekends and I don't want him stuck in the middle of the road with his girlfriend giving him the stinkeye.
We are definitely cost sensitive but I don't want to do this twice either.

Sounds like both the stock replacement and the conversion to external can be tricky. I'd love to find some shade-tree jeep mechanic who's made these repairs before so at least I can take the labor risk out of the equation.
@Krangler87 - appreciate the shop recommendation up 400. Is something like this right in their sweetspot? Or will they be watching the same youtube videos that I have? Looks like they do it all.

Honestly, Taylure I don't know. You would just have to call them and ask. I just know that they are honest folks and do good work. They might not even want to do it, I don't know.

Nothing will ever beat the reliability of the external setup. I owned my 89 since new and had one replaced under warranty and that one failed as well. Plastic has no place inside a bell housing. That said, the idea isn't exactly a bad one. GM's Blazer/Colorado/Canyon/Solstace/Sierra and others have better employed an internal slave with greater reliability. And as luck would have it, GM has an off the shelf solution for better internal slave's on the AX15. This would be for the more adventurous of you who like the better linear feel of the internal throw out over a fork based setup.

GM part number 89048231 is a front bearing retainer off a AISIN AR5. Aftermarket LUK LSC374 is the aluminum bodied slave.THe retainer even comes with a new seal already installed. Without out an exact measurement, approximately 1/4" has to be cut from the retainer's height. With this, the slave cylinder that GM uses would have the same collapsed height as the AX15's cylinder/retainer combo. Lastly, a custom adapted line would need to be made. I removed (where it's pinned in)the GM one and made a brass fitting to NPT threads with a braided clutch line kit off EBAY. Works like the original feel wise. My 2 cents.

Hey guys,
Thanks for the honest opinions here. I'm in the "restore and old jeep" camp and reliability is my biggest concern. I'll hand the keys over to my 16 year old when the weather is nice on weekends and I don't want him stuck in the middle of the road with his girlfriend giving him the stinkeye.
We are definitely cost sensitive but I don't want to do this twice either.

Sounds like both the stock replacement and the conversion to external can be tricky. I'd love to find some shade-tree jeep mechanic who's made these repairs before so at least I can take the labor risk out of the equation.
@Krangler87 - appreciate the shop recommendation up 400. Is something like this right in their sweetspot? Or will they be watching the same youtube videos that I have? Looks like they do it all.

Actually, I would say that the process is quite simple. I recently did the swap from Internal to External, and except for runs to get tools we were able to get it done in the basement. Really didn't even need to jack up the Jeep to do it except to clear the frame rails with the transmission on the trans jack.

I went with the External purely because I didn't want to have to go through it all again the next time. I had read horror stories about brand new Internal slaves leaking within months and the thought of doing it all again when I hadn't even done it the first time convinced me.

Now though, dropping the trans doesn't scare me anymore, but I'm still glad I swapped.

FYI - my 88 has the BA 10/5 transmission, so I'd have to upgrade to the AX15 to go with the external slave conversion.

Crossing my fingers on getting a good internal slave replacement part...

I went with the external slave after changing the internal 3 times in one year. The last one went to hell the first day I test rode it, There are several write ups on the various components needed, I found the bell housing on e-bay as well as several other parts. I bought the master and slave prebled. Some say the holes where the master goes in the firewall have to be modified but mine fit in w/o modification on my 92....russ

I’ve had a couple Jeeps with the Peugeot trans with the internal slave cylinder. I’ve gotten the best result by choosing fluids carefully. I read an article years ago that claimed that most of the problems with the internal slave cylinder come from using brake fluid that is not a good match for the seals. The article said the Ghirling brake fluid was recommended, but that Castrol-GT LMA was also compatible with the seals. I have used this fluid exclusively since then and have not had a problem with my internal slave since I changed it when I changed the clutch in 1997 (over 100,000 miles ago).

My shifting was radically improved by switching to high quality synthetic gear oil (I have used both Amsoil and Redline with good results). My 89 YJ now has about 220,000 miles on the original transmission and has had 2 clutches, and I have wheeled it pretty hard at times in its life.

I would recommend the swap to external. I’ve had the same nightmarish experience that other posters have had here with the internal slave cylinders - I’ve gone through 4 of them in the last 5 years. the average life span I got out of them is about 12-18 months, and maybe 3000 miles. I just did the swap with the last one - I know if that external one ever leaks, I can fix it myself, but from what I‘ve heard, the external slave cylinder doesn’t suffer from the same reliability issues

I swapped my internal to a new internal when a buddy owned my Jeep. A couple years later it was having the same squishy issues and pulling in air somehow. Im an ax5 4cyl.

When I had to do it the second time I went external and seems to be good. The parts to swap came along with some other items I snagged so I figured might as well. As I read more and more horror stories I'm glad I did so.

Not so relevant to the OP situation but for the record...

FYI places like to sell the hydraulics as a kit and brag about how you don't need to bleed them. Bleeding is easy and I don't see what all the hubbub is about so I bought components and kept my billfold fat. Im guessing that to try and nail guys like me they make the slave cylinders with the plastic bleed hole covered up. Still threaded and ready for a bleed plug but solid below. I can confirm you can simply drill it to 3/32 and thread in a set screw then you're off to the races not a leak or an issue from mine yet.