Symptoms
Sinking or spongy clutch pedal, fluid loss from the clutch reservoir, a slipping clutch after fluid has soaked the disc, and fluid at the bottom of the bellhousing.
The fix, step by step
- On early YJs (1987–92 per 4WD Mechanix; through 1993 per Wikipedia and Advance Adapters) the slave is part of the release bearing inside the bellhousing, so this is a clutch job. 4WD Mechanix's YJ/TJ procedure: remove the transfer case, loosen the hydraulic line with flare-nut wrenches, then drain and cap the line.
- Loosen the crankshaft position sensor so it isn't damaged, and unclip wiring.
- Support the transmission on a jack and the engine under the oil pan, and lower no more than about 3 inches.
- Slide the transmission and bellhousing straight back.
- Mark the flywheel and pressure plate, loosen the cover bolts in a crisscross pattern, and inspect the flywheel and pilot bearing.
- Fit a new disc and slave/release bearing, then bleed with clean DOT 3 or DOT 4 fluid.
Tools & part numbers
- Transmission jack
- flare-nut wrenches
- clutch alignment tool
- torque wrench
- brake washer (treat old linings as if they contain asbestos)
- DOT 3/4 fluid.
Where to buy the parts
Advance Adapters 716130IR-93 slave cylinder hose kit, 87–93 YJ (internal release bearing)Quadratec ↗Amazon ↗
YJ slave cylinders and control unitsQuadratec ↗Amazon ↗
Centerforce KDF193890 dual-friction clutch kit, 88–93 YJ 4.0LQuadratec ↗Amazon ↗
Crown master clutch kit, 89–91 YJ 4.0L/4.2L (AX-15)ExtremeTerrain ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Jeep Wrangler YJ parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.