Brake Fluid Flush
DOT 3 factory fill; DOT 4 acceptable upgrade for higher boiling point. Flush every 2-3 years; bleed sequence RR, LR, RF, LF.
XJ uses DOT 3 brake fluid from the factory across all years. DOT 4 is fully backward compatible and offers a higher boiling point - worthwhile if you run larger tires or tow. Do NOT use DOT 5 silicone fluid; it is not compatible with the ABS systems on 1991+ XJs. Brake fluid is hygroscopic - it absorbs water from the air and corrodes lines and calipers from the inside. Flush every two to three years. Bleed in the FSM order: right rear, left rear, right front, left front. Keep the master cylinder reservoir topped up so you do not introduce air. On ABS-equipped Jeeps (1991+) you cannot bleed the HCU without a scan tool that can cycle the ABS valves; a standard bleed at the wheel cylinders gets 95% of the old fluid out. A vacuum bleeder or pressure bleeder makes the job a one-person task; gravity bleeding works on the rear drums but is painfully slow.
Why it works
- Restores pedal feel
- Prevents caliper seizure
Trade-offs
- ABS HCU not flushed without scan tool
Tools required
- 10mm wrench (bleed screws)
- bleeder bottle
- vacuum or pressure bleeder helpful
Parts
| Part | Vendor | Est. price |
|---|---|---|
| DOT 3 or DOT 4 brake fluid (32 oz) | any | ~$8 |
Sources
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Written and maintained by an AZ wheeler and driveway wrencher. How we source guides. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.