How to Install Saginaw Power Steering Pump on 1990-1998 Ford RV Chassis: A Complete Guide

Short Answer

Installing a Saginaw steering pump on your 1990-1998 Ford 7.5L 460 engine RV can provide worthwhile improvements for steering response. The DM Motorsports conversion kit provides everything needed to swap from the original Ford pump to the higher-pressure Saginaw unit, which commonly operates at higher pressure levels than the original Ford pump (typical Ford pump: 1200-1350 PSI, Saginaw pump: consult manufacturer specifications for exact pressure rating). This increase in pressure can result in improved steering feel and reduced effort, especially when maneuvering your heavy RV at low speeds or when parked. The installation involves swapping the pump, modifying or replacing the pressure line, and potentially adjusting the power steering box settings to handle the increased pressure safely.

Understanding the Problem

WARNING: Always depressurize the power steering system before beginning work and wear safety glasses when working with hydraulic components under pressure.

Your Ford 7.5L 460 engine came from the factory with what many RV owners consider an underpowered steering system for the weight and size of these motorhomes. The original Ford power steering pump was designed more for lighter pickup trucks and vans, not the heavy motorhomes that many of these engines ended up powering (consult your RV specifications for exact weight). This mismatch can result in heavy steering feel, especially at parking lot speeds, and can make maneuvering your RV feel like a wrestling match.

The Saginaw pump upgrade addresses this fundamental design limitation. Saginaw pumps were originally used in GM heavy-duty applications and are known for their robust construction and higher pressure output. When DM Motorsports developed their conversion kit, they recognized that many RV owners were struggling with the inadequate steering assistance from the factory Ford setup. The higher pressure output of the Saginaw pump provides the additional hydraulic force needed to make steering your large RV feel more like driving a regular vehicle.

The pressure difference can be significant enough that you'll notice the improvement after installation. However, this increased pressure also means you need to ensure your steering box and related components can handle the additional hydraulic force. Most Ford steering boxes from this era can accommodate the higher pressure, but verify the steering box maximum pressure rating matches the Saginaw pump output pressure. Verify that your steering box's pressure relief valve rating is compatible with the higher pressure output - most steering boxes have fixed pressure relief valves that cannot be field-adjusted. Have the system checked if your steering box is showing signs of wear or leakage before doing the conversion.

Another consideration is that the improved steering response might feel overly sensitive at highway speeds initially. Many RVers who've done this conversion report a brief adjustment period where they need to develop a lighter touch on the steering wheel during highway driving. The trade-off may be worth it for the dramatically improved low-speed maneuverability, but it's something to be aware of as you adapt to the upgraded system.

What You'll Need

The DM Motorsports kit you mentioned is a recognized solution for this conversion, and they've refined it over the years based on feedback from RV owners who've completed the installation. The complete kit typically includes the remanufactured Saginaw power steering pump, all necessary mounting brackets and hardware, the modified high-pressure line, and detailed installation instructions specific to the Ford 460 engine bay layout.

Beyond the kit itself, you'll need some additional supplies and tools to complete the installation properly. Plan on purchasing about two quarts of fresh power steering fluid, as you'll need to completely flush the old fluid during the conversion process. ATF Mercon is typically the specified fluid for these Ford systems, though some prefer dedicated power steering fluid for its superior high-temperature properties.

Tool-wise, you'll need a comprehensive socket set including both standard and metric sizes, as Ford used a mix during this era. A good set of line wrenches is essential for disconnecting the hydraulic lines without damaging the fittings. You'll also need a large drain pan capable of holding at least a gallon, as power steering systems can be surprisingly messy when you're working with the lines and pump.

A power steering pulley puller and installer set is absolutely critical for this job. The Saginaw pump uses a different pulley configuration than the Ford pump, and attempting to remove or install these pulleys without the proper tools typically results in damaged components. These tool sets are available from most auto parts stores as loaner tools if you don't want to purchase them outright.

Consider having a serpentine belt routing diagram handy for your specific year, as you'll be removing and reinstalling the belt during this process. While the routing typically doesn't change, having the diagram prevents any confusion during reassembly. You might also want to have a backup serpentine belt available, as this is a good time to replace it if it's showing any signs of wear.

How to Fix It

WARNING: Power steering systems operate under high pressure and can cause serious injury. Always wear safety glasses and depressurize the system before disconnecting any lines. Be aware that component failure under high pressure can result in loss of steering control.

Start this conversion with the engine completely cold, preferably after sitting overnight. Ensure the vehicle is parked on level ground with wheels chocked and parking brake engaged. If working underneath the vehicle, use proper jack stands - never rely on jacks alone. The power steering system retains a surprising amount of pressure even after the engine is shut off, and working with hot components makes the job more difficult and potentially dangerous. Begin by disconnecting the negative battery terminal to prevent any accidental electrical issues while you're working around the engine bay.

Your first step is draining the existing power steering fluid from the system. Remove the return line from the power steering reservoir and let it drain into your catch pan. You can speed this process by gently lifting the front of the RV or turning the steering wheel from lock to lock while the return line drains. This helps purge most of the old fluid from the steering box and lines.

Next, you'll need to remove the serpentine belt to access the power steering pump pulley. Mark the belt routing with chalk or a marker before removal, even if you have a diagram. Remove the pulley from the original Ford pump using your pulley puller tool. This requires steady pressure and patience - rushing this step often results in a damaged pulley or pump shaft.

Disconnect both the high-pressure line and return line from the Ford pump. The high-pressure line typically uses a banjo fitting with copper crush washers, while the return line is usually a simple hose clamp connection. Clean these fittings thoroughly and inspect the lines for any signs of deterioration. If the return line looks questionable, replace it now while everything is accessible.

Remove the Ford pump by unbolting it from its mounting bracket. The mounting points vary slightly between years, but typically involve three bolts - two at the bottom of the pump and one at the top rear. The DM Motorsports kit includes adapter brackets that allow the Saginaw pump to mount in the same location, though the bolt pattern is different.

Install the Saginaw pump using the provided mounting hardware from the kit. Follow the kit instructions for proper torque specifications and complete the installation according to manufacturer guidelines. Follow manufacturer specifications to prevent stress cracking of the mounting ears. Install the new pulley on the Saginaw pump using your pulley installation tool, ensuring it's pressed on to the proper depth as specified in the kit instructions.

The high-pressure line modification is often the trickiest part of this conversion. The DM Motorsports kit includes a modified line with the correct fittings for both ends. Follow the kit instructions for proper routing and connection of the high-pressure line, ensuring all fittings are torqued to specification. Install the pump fitting and your Ford steering box. Route this line carefully to avoid any contact with moving parts or excessive heat sources. Use the provided brackets and cushions to secure the line and prevent vibration-related wear.

Reconnect the return line to the new pump and ensure all connections are tight. Reinstall the serpentine belt following your marked routing or diagram. Before adding fluid, double-check that all connections are secure and properly torqued. Fill the power steering reservoir with fresh fluid, but don't overfill - leave room for expansion and aeration during the bleeding process.

The bleeding process is critical for proper operation and system longevity. Start the engine and immediately begin turning the steering wheel slowly from lock to lock. You'll hear considerable noise initially as air works its way out of the system. Keep the fluid level topped up during this process, as it will drop significantly as air is purged. Continue this process for at least ten minutes or until the noise subsides and the fluid level stabilizes.

Take your RV for a test drive, starting with gentle maneuvers in a large parking lot. The steering response should feel noticeably lighter and more responsive. Pay attention to any unusual noises, vibrations, or steering behavior. It's normal for the system to require a brief break-in period, during which you might hear occasional minor noise as any remaining air works its way out.

Leave It to the Experts

While this conversion is within the capabilities of most DIY RV mechanics, there are several situations where professional installation makes sense. If your RV's power steering system has been problematic or if you've noticed any leakage from the steering box, having a professional assess the entire system before the pump conversion is wise. A weak or worn steering box won't benefit from the increased pressure and could fail shortly after the conversion.

The hydraulic line work can be particularly challenging if you're not comfortable working with high-pressure fittings. Improperly installed or torqued fittings can result in dangerous fluid leaks or complete system failure. Professional shops have the experience to quickly identify potential issues with line routing, fitting compatibility, or clearance problems that might not be obvious to a first-time installer.

If your RV is still under any warranty coverage, having the conversion done professionally provides documentation and accountability that could be important for future warranty claims. Some extended warranty providers specifically exclude coverage for systems that have been modified by non-professional installers, even if the modification itself is unrelated to the failure.

Professional installation typically runs between $400 and $600 in labor costs, depending on your location and the complexity of your specific installation. This includes proper system bleeding, testing, and often a brief test drive to ensure everything is functioning correctly. Many shops that specialize in RV service are familiar with this conversion and can complete it efficiently.

Consider professional installation if you don't have access to the proper tools, particularly the pulley removal and installation equipment. While these tools can be borrowed from parts stores, inexperience with their use can easily result in damaged components that cost more to replace than the professional installation would have cost initially.