After sitting in the Core 4x4 shop for more than five years, this XJ Cherokee has been through a full long arm kit, WJ knuckle swap, hack and tab lift, and just about every suspension upgrade you can throw at a Jeep. Now it is time to finish the loose ends, get it running, and prep it for its first off-road test. Gabby and Spence walk through every step — from bleeding brakes to flex testing — so you can use the same checklist on your own XJ build.
This is the kind of video that does not get enough attention. Everyone wants to see the big install, but the final prep work is what separates a Jeep that drives from one that sits on jack stands. If you have a project XJ that is close to done but not quite there, this is your roadmap.
Fitment: Jeep Cherokee XJ (1984–2001) | Applicable to any XJ build with aftermarket suspension
The Starting Point: A Long-Dormant XJ
This XJ had not been started or driven since it arrived at the Core 4x4 shop. Over the course of the build series, the team installed a complete long arm suspension kit, performed a WJ knuckle swap for improved steering geometry, and did a hack and tab lift — basically rebuilding the suspension from scratch. But a Jeep on a lift is not a Jeep on the trail. Before it can go anywhere, it needs:
- A running engine (suspected fuel pump issue)
- Brake lines bled and leak-free
- All suspension hardware torqued to spec
- Bushings greased
- Clearance check and flex test
- Bump stop evaluation
Getting the XJ Running
The initial diagnosis pointed to a bad fuel pump — the Jeep had been sitting for years and the pump was not priming. After replacing the fuel pump, the first start attempt was a success on the very first try. No extended cranking, no additional diagnosis needed. Sometimes you get lucky.
Tip: If your XJ has been sitting for an extended period, replace the fuel pump and fuel filter before trying to diagnose other starting issues. Old fuel and a dead pump account for the majority of no-start conditions on stored Cherokees.
How to Bleed Brakes on a Jeep XJ Cherokee
With the engine running, the team moved it back slightly and found brake pressure issues immediately. Some of the brake line fittings were leaking — not uncommon when you are working with older, rusty hard lines. They tightened the connections on the front calipers and the extended rear brake line before starting the bleed process.
Brake Bleeding Order
Always start at the wheel that is furthest from the master cylinder and work your way closer:
- Passenger rear
- Driver rear
- Passenger front
- Driver front
The Process
- Have a helper in the cab press and hold the brake pedal
- Open the bleeder valve on the caliper — fluid and air will push out, and the pedal will drop to the floor
- Close the bleeder valve before the helper releases the pedal — if you open the valve with no pressure, you will suck air back into the system
- Repeat 3–5 times per wheel until you see clean fluid with no air bubbles
- Check and refill the master cylinder reservoir between each wheel — if it runs dry, air enters from the top and you start over
DIY Brake Bleeder Setup
Spence uses a simple setup: a piece of clear rubber hose attached to the bleeder valve, running into a small catch bottle partially filled with brake fluid. The clear tubing lets you watch for air bubbles in real time. Keep the bottle higher than the bleeder valve so gravity helps prevent air from getting sucked back in.
This is not a fancy speed bleeder or vacuum pump setup — it is a rubber hose and a bottle. It works perfectly for a project like this where you have new lines and calipers with a lot of air in the system.
Greasing Bushings and Torquing Suspension Hardware
With the brakes sorted, the team raised the XJ on the lift to grease all the suspension bushings and torque down jam nuts and hardware. This includes every Johnny Joint, every jam nut on the long arms, and all the mounting bolts.
The Critical Bushing Rule
This is the most important thing to remember when finishing any suspension install on an XJ — or any Jeep, for that matter:
Johnny Joints: Can be torqued in the air at full droop. The independent crush sleeve inside a Johnny Joint means the bolt clamps the sleeve, not the joint itself. There is no preload concern.
Rubber or polyurethane bushings: NEVER torque in the air. The sleeve inside a rubber bushing is bonded to the rubber. If you torque it at full droop, the rubber locks in that position. When you set the Jeep down and the suspension compresses, the bushing cannot rotate — it creates a preload that will destroy the bushing prematurely.
On this XJ, the front axle housing bushings and the leaf spring bushings are still rubber. Those were left loose until the Jeep was back on the ground under its own weight. Everything with a Johnny Joint was torqued on the lift.
Removing the Front Bumper for Clearance Testing
Before taking the XJ for its first drive, the team removed the factory front bumper. They are planning aftermarket bumpers down the road, so pulling the stock piece now gives them a clear view of front tire clearance during the flex test. It also makes it easier to evaluate where trimming might be needed once fender flares are selected.
First Test Drive and Track Bar Adjustment
With the brakes bled, suspension torqued (rubber bushings done on the ground), and bumper removed, the XJ went for its first-ever drive after the build. The team took it around the block for a shakedown run to check for any obvious issues.
The only immediate adjustment needed was the track bar. After setting it, the steering wheel was slightly off center. On an XJ with an adjustable track bar, this is a quick fix — loosen the jam nuts, adjust the length, and re-center the steering wheel. The team also noted:
- Front fender contact: The tire was hitting the front fender flare area, which was expected on 35-inch tires with a 4-inch lift
- Rear clearance: The rear was clearing well because the axle was positioned slightly forward of stock
- Alignment needed: A proper alignment is required before any serious driving
Flex Test: What to Look For
The team drove the XJ over to Core 4x4's other shop and used a forklift to flex each corner. This is the standard method for checking suspension clearance at full articulation when you do not have a dedicated ramp or rock pile.
What They Found
At full tuck (maximum upward travel), several things became clear:
- Rear clearance: The rear tires were clearing fine — no contact with the body
- Rear mud flaps: The tires were hitting the rear mud flaps. Those need to come off
- Front wheel well: The tire was fully tucking into the front wheel well and contacting the body. The sheet metal was starting to bend
- Bump stops: The factory bump stop extensions that were previously on the Jeep had been removed during the kit install. New ones are needed
Options for Fixing Front Clearance
When your tires are hitting the body at full tuck, you have three options:
- Bump stop extensions: Limit the upward travel so the tire stops before it contacts the body. Core 4x4 makes bump stop extensions for XJ Cherokees
- Trimming: Cut away the inner fender or body metal to give the tire more room. This is permanent but gives you maximum travel
- Combination: Trim some metal for extra clearance, then use bump stops to fine-tune the limit. This is what Spence recommends
Spence's take: "I like to trim and have as much up travel as we can. You can over-compress your coils if you go crazy and wear them out prematurely, but I've never really worried about that. We'll probably do a combination of bump stops and trimming some of the steel when we go to do fender flares on this."
XJ Off-Road Prep Checklist
If you are finishing a build and getting ready to take your XJ off road for the first time, here is the full checklist from this video:
| Task | Notes |
|---|---|
| Engine starts and runs | Replace fuel pump and filter if the XJ has been sitting |
| Brake lines tightened | Check every fitting — rusty lines strip easily |
| Brakes bled | Start at passenger rear, work toward driver front |
| Master cylinder full | Check between each wheel during bleeding |
| Johnny Joints torqued | Safe to torque in the air (independent crush sleeve) |
| Rubber bushings torqued | Must be at ride height with full vehicle weight |
| Jam nuts torqued | 250 ft-lbs on lowers, 200 ft-lbs on uppers |
| All bushings greased | Grease every joint before first drive |
| Track bar adjusted | Center steering wheel, re-torque jam nuts |
| Bump stops evaluated | Flex test to check if bump stops are needed |
| Clearance check | Use forklift or ramp to full-tuck each corner |
| Alignment | Required before highway driving or trail use |
Frequently Asked Questions
What Is Next for the XJ Build
With the XJ running, driving, and flex-tested, the next steps in the build series are fender flares (to gain clearance and clean up the wheel wells), aftermarket front and rear bumpers, bump stop extensions, and eventually hitting the trail. The team is waiting to select fender flares before doing any major trimming so the flares and cuts work together.
Shop XJ Cherokee Parts
Fitment: Jeep Cherokee XJ 1984–2001 | Questions? sales@core4x4.com | (385) 375-2104
