When the Wrangler JL was introduced in 2018, it came with many technologies that were new to the Wrangler platform.

One of these was the more efficient electric-over-hydraulic steering system that was no longer driven off the front engine accessory drive. This setup improves efficiency of the drivetrain by using an electric pump that is divorced from engine speed to run the steering hydraulics.

Electrohydraulic systems also have the added benefit of remaining at a consistent pressure until there is resistance, where they max out on pressure through a pre-set relief valve. Unfortunately, on the JL, system pressure is set with factory 33- or 35-inch tires and thermal management in mind.


Step 1

The APEX kit comes complete with everything you need to modify your stock steering system, including high-quality hardware and a proprietary APEX cooler and brackets.

Even at around 1,300 psi (1,500 psi on XR-equipped JLs), stock Jeep owners may feel a hesitation or latency in steering assist as the pump catches up, especially on high traction surfaces, such as pavement or a slick rock trail, and when aired down. Increasing tire size will exacerbate the problem and can extend the drivability issues to tires that are aired up.


Step 2

To access the pump, which sits on the passenger-side frame rail, we pulled back the inner fender liner.

To combat this problem, there are several options in the aftermarket that range from ram-assist to replacing the electrohydraulic steering with a full hydraulic setup. These upgrades, while effective, can be complex and cost several thousands of dollars in parts alone.

Fortunately, Jeep selected an extremely high-quality electric pump with helical gears and a brushless motor that is capable of handling more than 1,800 psi. However, while running at this pressure creates more assist, it also creates more heat and the factory steering system doesn’t have a cooler to manage it.


Step 3

This is a closer look at the electric pump and its positioning. It is in the same location on all JLs; however, the location of the airbox and other components make the installation a bit more straightforward on a Wrangler 392.

Enter APEX Performance Products and the company’s JL/JT steering boost kits. These kits are a complete solution and include everything you need (except for fresh fluid) to safely boost the pressure available to your steering system.

Using an adjustable blow-off valve and a new extruded aluminum cooler, the APEX kit can increase stock steering power by up to 40 percent, more than enough for someone running 37- to 39-inch tires. It is worth noting that when running 40-inch tires or larger, the APEX kit alone will not provide as much of a noticeable gain, but it can be combined with a ram-assist kit on stock steering for maximum benefit.


Step 4

To give us better access to the steering system lines, we removed the AEV skid plate and the factory electronically disconnecting sway bar.


Step 5

Next, the factory steering line was unfastened from the crossmember so that we could test fit the steering fluid cooler in its intended location and check for clearance.

As APEX reiterates several times on the company website and in the upgrade instructions, the provided oil cooler and the proper steering fluid are essential to making this steering upgrade safe for the system’s components.

Mopar requires a very specific, high-quality synthetic hydraulic fluid that meets or exceeds the MA-11655 specification. This fluid is heat resistant up to about 400 degrees, at which time it will start to deteriorate, taking seals and other components with it. This specialized fluid cannot be skimped on and is only available through Mopar and a couple of aftermarket companies.


Step 6

The cooler requires minor assembly, such as installing the hose barb at each end. We were sure to coat the O-ring in power steering fluid before installing and torquing to spec.


Step 7

After installing the nipples, we installed the mounting bracket into the T-slot of the cooler extrusion.

We decided to install the APEX kit on our ’23 Jeep Wrangler 392 (the kit is compatible with all versions of the JL), with the full American Expedition Vehicles (AEV) JL370 package and 37-inch tires. Because of our tire size and the difficulty steering at low speeds in certain situations, we felt the budget-friendly APEX kit, at less than $400 retail, was the right choice.

The kit fills a void for wheelers like us who have no intention of running anything bigger than a 38-inch tire and don’t need the overkill or added complexity of a ram-assist setup.


Step 8

The JL is incredibly tight on space under the front end and the APEX cooler has been sized to take up a small dead zone underneath the radiator, ahead of the crossmember, where it won’t interfere with suspension components.


Step 9

With the cooler positioned, we located the low-pressure hard line and severed it with a tube cutter, partially draining the system.

With parts in hand, we headed over to our friend Chris Johnson’s Rock-Tech Offroad shop in La Habra, California, where we spent about a half day documenting the installation of the APEX steering boost kit on our JL.

Once it was installed, a few things were immediately noticeable. First, the steering feels perfectly stock-like and well-weighted when driving around town. We aired down our tires to 12 psi and made tight turns in a parking lot to simulate previous situations where steering stall would occur, and the Jeep system was able to keep up with wheel inputs without issue.


Step 10

Next, we made additional cuts to the factory line per the provided instructions and removed all of the factory line that wouldn’t be reused.


Step 11

We then turned our attention to removing the pump. Starting with the reservoir, we disconnected it to drain it and make handling the pump easier.

We also noticed that there was less kickback through the wheel from potholes on the road and rocks on the trail, no doubt because of the higher pressures now available to the system.

Overall, this might be one of the best mods we’ve made to our Jeep, and one that includes a noticeable benefit in everyday drivability as well as improved steering on the trail. We are extremely happy with the performance, especially for the price point, and highly recommend it to anyone looking to improve the steering on their Wrangler or Gladiator.


Step 12

The pump has a bracket holding it in, along with a couple of electrical connectors and lines that need to be disconnected.


Step 13

After disconnecting everything, the pump is easily removed through the passenger-side wheel well.

Of note, this kit was installed on a late-model JL with the later cast iron steering box. We would highly recommend those with earlier aluminum boxes upgrade to a cast iron box before making this modification to get the most out of it.

Read this article’s accompanying pictures to see what it takes to add affordable steering performance to your ’18-current Jeep Wrangler JL or Gladiator JT.


Step 14

Once the pump was free of the Jeep, we positioned it on the bench with the pressure fitting positioned vertically and carefully removed it.


Step 15

The adjustable APEX pressure valve that replaces the factory part uses a 5mm hex to adjust it, which needs to be completely backed out prior to installation to form a baseline before setting the pressure.


Step 16

Since we had the pump out, we took the opportunity to attach the supplied low-pressure rubber hose to the nipple on the back of the pump. This line goes to the passenger side of the steering cooler.


Step 17

Next, we assembled the pressure gauge and installed it to the new distribution block fitting before returning the pump to its original location. While the gauge can remain in place indefinitely, we recommend removing it after the pressure is set to remove any potential failure points.


Step 18

Returning to the high-pressure line, we re-shaped it by hand so that it would clear any areas it could potentially rub.


Step 19

Before we could finish hooking up the system, we had to cut the stock low-pressure line in the driver’s fender well and install the supplied double-barb fitting and hose, which connects to the driver’s side of the cooler.


Step 20

That hose drops down along the frame rail, and you can see it being connected to the APEX steering cooler here.


Step 21

With all of the fittings connected, we secured the power steering fluid reservoir and filled up the steering system with Mopar 68088485AB synthetic power steering fluid.


Step 22

After starting up the engine and checking for leaks, we reinstalled the stabilizer bar and AEV parts before bleeding the steering system. Before reinstalling the AEV skid plate, we took one last look at how nicely the APEX cooler nestles under the Jeep without interfering with any other components.


Step 23

The final step to the install is to set the pressure, which is a two-person operation. With the engine running, hold the steering wheel at full lock and note the pressure reading, which should start below 1,000 psi. Turn the vehicle off and then screw the adjuster in by a quarter turn (never go more than ¼ turn at a time or you risk overrunning the pressure). Repeat this procedure until the pressure alleviates any power steering issues. In our case, with 37-inch tires, we set our pressure around 1,900 psi.



APEX Performance Products

Rock-Tech Offroad


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This article originally appeared in OVR Issue 05. For more informative articles like this, consider subscribing to OVR Magazine in print or digital versions here. You can also find the print edition of OVR at your local newsstand by using our Magazine Finder.