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If you drive a Subaru Forester regularly, hot steering fluid can lead to reduced performance, heavier steering feel, and accelerated component wear. Choosing the right power steering cooler helps manage operating temperatures so steering remains predictable and components last longer. This guide highlights seven shortlisted options selected for compatibility with the Subaru Forester and strengths across cooling efficiency and installation simplicity. Read on to understand the evaluation criteria and which cooler features matter most before you commit to an upgrade.
Looking for other parts? See all Subaru Forester parts & accessories.
Top Picks at a Glance
| Best Overall The best all-around choice for most situations | Derale Series 7000 Power Steering Cooler Kit |  |
| Best Quality Built to a higher standard if you want something more solid | Mishimoto Universal Transmission / Power Steering Cooler |  |
| Best Value The sweet spot between price and what you get | Derale 13200 Power Steering Cooler Kit |  |
| Best budget The cheapest option that still gets the job done reliably | Allstar Performance Power Steering Cooler ALL52100 |  |
| Highest Rated A top-rated pick with lots of positive feedback | Hayden 1009 Power Steering Oil Cooler (9 inch) |  |
| Best Seller A high-volume bestseller chosen again and again | Hayden Automotive 1011 Power Steering Oil Cooler |  |
1. Derale Series 7000 Power Steering Cooler Kit
| Material | Aluminum/Copper |
|---|---|
| Inlet/Outlet | 11/32 in Hose Barb |
| Finish | Black Powder Coat |
| Type | Tube and Fin Core |
The Derale Series 7000 power steering cooler kit is a small tube-and-fin cooler intended to lower steering fluid temperature for improved system longevity and consistent steering feel. It installs inline using 11/32 inch hose barb fittings and includes mounting hardware and hose, so it is typically used between the power steering pump and rack or reservoir to shed heat during towing, spirited driving, or stop-and-go traffic. The aluminum and copper construction with a black powder coat gives corrosion resistance and a tidy under-hood appearance. Its compact core fits in tight spaces behind the bumper or near the radiator while still offering better thermal transfer than an uncooled line. Limitations are its modest core size, which means it is best for everyday performance improvement rather than heavy-duty cooling for large towing loads, and hose barb fittings require secure clamp connections to avoid leaks. Overall it is a straightforward, durable factory-replacement style cooler for owners who want lower steering fluid temps without complex plumbing.
Best for: Balanced all-round buyers who want a reliable, easy-to-install cooler to lower power steering fluid temperatures for improved steering consistency and component life without major modifications.
Less Ideal for: Owners who need heavy-duty cooling for frequent towing, motorsport use, or substantially modified steering systems should choose a larger or purpose-built cooler.
- Aluminum/copper tube-and-fin design provides efficient heat transfer for its size
- Compact core and included hardware allow installation in tight engine bays
- Black powder coat finish offers corrosion resistance and a clean appearance
- Includes hose and fittings for a mostly complete install
- Small core size limits cooling capacity for heavy towing or extreme use
- Uses hose barb fittings that require careful clamping to prevent leaks
Verdict: A compact, durable inline power steering cooler that lowers fluid temperatures with minimal fuss for everyday driving and light towing.
2. Mishimoto Universal Transmission / Power Steering Cooler
| Material Type | Aluminum |
|---|---|
| Item Length | 15.5 Inches |
| Nominal Wall Thickness | 0.75 inches |
| Outside Diameter | 0.38 Inches |
The Mishimoto universal cooler is a compact, all-aluminum heat exchanger intended to reduce operating temperatures for automatic transmissions or power steering systems. It mounts to a radiator or core support using the included tie straps and foam pads and connects with 3/8-inch push-on fittings for a straightforward hose hookup. In real-world use it provides measurable temperature reduction when placed where airflow reaches the core, and reviewers report easy installs on vehicles that lost transmission ports after switching to aluminum radiators. The unit ships with hoses, clamps, O-ring fittings, and simple mounting hardware, and Mishimoto backs it with a lifetime warranty. Trade-offs are its small footprint and basic mounting kit, which can limit placement options and may require creative securing or an additional fan for tight engine bays; it also uses push-on fittings rather than threaded ports which some installers prefer. For a performance-minded cooling upgrade this cooler is a practical, factory-quality way to add extra fluid cooling without a vehicle-specific bracket.
Best for: Performance-oriented owners who prioritize reducing transmission or power steering temperatures on modified or high-load Subaru Foresters and want a compact, reliable aftermarket cooling upgrade.
Less Ideal for: Owners seeking a vehicle-specific plug-and-play solution with dedicated brackets or those who need very high-capacity cooling for heavy towing should consider larger or model-specific coolers.
- All-aluminum construction for efficient heat transfer and corrosion resistance
- Universal mounting that fits many installations including radiator-mounted setups
- Includes hoses, clamps, foam pads and tie straps for a basic plug-and-play install
- 3/8-inch push-on fittings simplify hose connections without special adapters
- Small core size limits maximum cooling capacity under extreme loads
- Basic attachment hardware may need reinforcement or alternative brackets for secure long-term mounting
Verdict: A compact, lifetime-warrantied aluminum cooler that adds reliable fluid temperature control for performance-focused Forester builds.
3. Derale 13200 Power Steering Cooler Kit
| Special Feature | Expanded Copper Tubing and Aluminum Cooling Fins |
|---|---|
| Inlet Size | 11/32 inch hose barb inlets |
| Model Name | 13200 |
| Installation Type | Self-Adhesive |
The Derale 13200 is a compact power steering cooler kit intended to reduce fluid temperature and help prevent heat-related pump failure. It mounts in front of the radiator or condenser and routes steering fluid through 1/2 inch copper tubing expanded into aluminum cooling fins to shed heat during normal driving and towing. The kit includes hose barb inlets and basic hardware for bolt-on installation, making it a straightforward add-on for routine maintenance or cooling upgrades. In practice it lowers operating temperature during prolonged low-speed or high-load use and can extend pump and seal life when heat is a factor. Because it is a simple inline cooler with a medium core area, cooling is effective for daily driving and light-duty towing but may be modest compared with larger or multi-pass coolers. Installation is practical for a home mechanic but may require careful routing to avoid chafing or kinking of the lines.
Best for: Convenience-driven buyers who want a simple, low-effort upgrade to reduce steering fluid heat and prolong pump life without major modification.
Less Ideal for: Drivers who frequently do heavy towing, competitive driving, or need maximum multi-pass cooling should consider larger or purpose-built heavy-duty coolers instead.
- Compact core with expanded copper tubing and aluminum fins for efficient heat transfer
- Includes hose barb inlets and hardware for a straightforward installation
- Small footprint fits in tight spaces ahead of the radiator or condenser
- Helps lower steering fluid temperature to reduce pump and seal stress
- Cooling capacity is moderate and may be insufficient for heavy towing or extreme-duty use
- Does not include detailed vehicle-specific fitment instructions
Verdict: A compact, easy-to-install power steering cooler that reduces fluid temperature and helps extend pump life for everyday and light-duty use.
4. Allstar Performance Power Steering Cooler ALL52100
| Model | ALL52100 |
|---|---|
| Exterior | Machined |
| Includes fittings | -6 fittings |
The Allstar Performance ALL52100 is a small, machined inline cooler that bolts or ties to a chassis or cooler mount to lower transmission or power steering fluid temperature by about 30 degrees under use. It installs with two 1/4" bolts or tie wraps and includes -6 fittings, so typical installation on a Forester's power steering line requires basic hose adapters and simple mounting hardware. The unit's milled slot accepts a bolt head for adjustable mounting and its compact length lets it fit in tight engine bays. Practical benefits include noticeable fluid cooling during towing, track use, or prolonged steering loads and straightforward, no-frills construction that keeps cost low. Limitations are its basic fittings and end caps, which some users report do not seal as well as higher-end coolers, and the product ships without dedicated mounting hardware or detailed instructions, so expect to source bolts, adapters, and thread sealant. If you want a low-cost, compact cooler to help reduce steering fluid heat on a Subaru Forester, this is a functional budget choice with modest performance and some assembly required.
Best for: Budget-conscious Subaru Forester owners who want a simple, low-cost way to lower power steering fluid temperatures for towing, light track use, or heavy steering loads without upgrading to an expensive cooling system.
Less Ideal for: Drivers seeking a plug-and-play, professional-grade cooler with premium fittings and full mounting kits should consider higher-end models that include hardware and better-sealed connections.
- Compact length fits tight engine bays and allows flexible mounting positions
- Machined exterior with a milled slot for captured bolt mounting and adjustability
- Claims to reduce fluid temperature by about 30 degrees in real-world use
- Includes -6 fittings suitable for common aftermarket hose sizes
- Does not include mounting hardware or installation instructions
- Reported issues with end cap sealing and fitting quality on some units
Verdict: A compact, low-cost power steering cooler that delivers basic fluid temperature reduction for Forester owners who will supply their own fittings and mounting hardware.
5. Hayden 1009 Power Steering Oil Cooler (9 inch)
| Material | Aluminum |
|---|---|
| Overall Length | 9 Inches |
| Fits Hose I.D. | 3/8 Inch |
| Construction | Tube, Fin |
The Hayden 1009 is a compact aluminum power steering oil cooler intended to lower operating temperature in hydraulic steering systems by increasing fluid surface area and airflow. It mounts inline with 3/8-inch I.D. return hose lines and is commonly used on vehicles that see towing, larger tires, or prolonged low-speed steering work where fluid heat builds up. The unit includes mounting hardware and uses a tube-and-fin, two-row construction to improve heat rejection while remaining lightweight and machined for corrosion resistance. Installation is straightforward for a competent DIYer and the cooler helps reduce wear on pumps, hoses, seals, and fluid by keeping temperatures in check. Limitations include its fixed 9-inch length and 3/8-inch fittings, which restrict fitment to systems that accept that hose size, and it is a single-purpose add-on so it does not address underlying steering component faults.
Best for: Reliability-focused owners who want to reduce steering-system heat and extend the life of pumps, seals, hoses, and fluid without major modifications.
Less Ideal for: Drivers looking for universal fitment or adjustable plumbing options should consider models with multiple inlet sizes or adapter kits instead.
- Aluminum tube-and-fin construction for effective heat dissipation and corrosion resistance
- Includes mounting hardware for straightforward installation
- Designed for 3/8-inch I.D. return hose common on many power steering systems
- Compact 9-inch length fits tight engine bays where larger coolers will not
- Fixed 3/8-inch hose connection limits compatibility with systems using different hose sizes
- No adjustable fittings or adapters included for nonstandard plumbing
Verdict: A compact, aluminum inline cooler that reliably lowers power steering fluid temperature to help preserve system components.
6. Hayden Automotive 1011 Power Steering Oil Cooler
| Model | Power Steering Oil Cooler 1011 |
|---|---|
| Recommended hose I.D. | 3/8 inch |
| Exterior | Machined |
| Unit count | 1.0 Count |
| Manufacturer | Hayden Automotive |
The Hayden 1011 power steering oil cooler is an inline cooler intended to reduce operating temperature in power steering systems where heat is a concern, like vehicles with larger tires or frequent low-speed work. It installs in the return hose and comes with mounting hardware for a straightforward bolt-up. By shedding heat it helps protect the pump, hoses, seals and fluid, which can reduce premature failures and maintenance on older or heavily used systems. The unit is machined for durability and sized for systems using 3/8 inch I.D. return hose; Hayden offers similar coolers for different duty levels. Limitations are that fitment depends on hose inner diameter and available mounting space, and it does not include hose or fittings beyond the supplied bracket hardware, so installers should verify hose size and routing before purchase.
Best for: A risk-averse mainstream buyer looking to protect factory steering components on a Scion tC by reducing heat-related wear and extending service intervals.
Less Ideal for: Drivers who need a universal, tool-free retrofit or who cannot accommodate a small inline cooler in their engine bay should consider integrated radiator-mount options or professional installation.
- Reduces power steering fluid temperature to help prolong pump and hose life
- Machined exterior for a durable, serviceable finish
- Includes mounting hardware for simpler installation
- Sized for common 3/8 inch I.D. return hoses used in many aftermarket setups
- Requires matching hose inner diameter and enough underhood space for installation
Verdict: A compact, machined inline cooler that lowers steering fluid temperatures to help extend the life of Scion tC power steering components.
Choosing the Right Subaru Forester Power Steering Cooler: Key Factors to Consider
Cooling Capacity and Core Design
Cooling capacity determines how effectively a cooler reduces steering fluid temperature during prolonged or heavy use. Larger cores or multi-pass designs typically offer greater heat dissipation, which helps prevent fluid breakdown and maintains consistent steering feel under load.
Core construction affects airflow and thermal transfer. Finned, multi-row cores increase surface area and improve heat exchange without necessarily increasing installation footprint. Consider how often you tow, carry heavy loads, or drive in hilly terrain, as those conditions increase the demand on the cooler.
Mounting Location and Bracket Fitment
Where the cooler mounts affects both performance and ease of installation. Front-of-vehicle locations with good airflow provide the best cooling, but limited space or local components can constrain options.
Look for kits that include purpose-built brackets or adapters for the Forester to avoid drilling or cutting. Mounting position also influences hose routing length and exposure to road debris, so evaluate clearance and protection when planning installation.
Hose and Fitting Compatibility
Proper hose and fitting sizes ensure a leak-free, reliable connection between the power steering system and the cooler. Mismatched threads or inadequate hose ratings can lead to leaks or premature failure under pressure.
Check whether the kit supplies braided or pressure-rated hoses, and whether adapters are required for the Forester's factory lines. Ease of connection reduces installation time and lowers the chance of future maintenance issues.
Material Quality and Corrosion Resistance
Materials determine how well a cooler withstands road salt, moisture, and mechanical wear. Aluminum cores with protective coatings are common because they balance thermal performance with corrosion resistance and weight savings.
Pay attention to welded joints, brazing quality, and protective finishes on both the core and fittings. Higher-quality materials reduce the risk of leaks and extend service life, particularly if you drive in coastal or winter conditions.
Pressure and Flow Ratings
A cooler must tolerate the system pressures and maintain adequate flow so steering performance is not compromised. Units rated for low pressure or with restrictive internal passages can cause steering noise, slower response, or increased pump strain.
Verify published pressure and flow specifications and look for designs intended for hydraulic steering systems. Components that match or exceed factory pressure tolerances reduce the chance of failure and maintain steering system reliability.
Installation Complexity and Included Hardware
Installation complexity affects time, tools required, and potential for mistakes. Kits that include all necessary fittings, hoses, and vehicle-specific brackets minimize surprises and make a cleaner installation.
Consider whether you can perform the install with basic tools and a friend to help, or if professional installation will be more practical. Simpler installations reduce downtime and lower the chance of incorrect routing or inadequate fastening that can lead to problems later.
How We Chose the Best Subaru Forester Power Steering Cooler
We screened options for compatibility with the Subaru Forester and prioritized fitment confidence, measurable cooling capacity, and installation practicality. Cooling capacity and core design were weighted heavily because they directly affect how much fluid temperature drops under sustained use. We also evaluated mounting options and hardware included to ensure the cooler can be secured without extensive fabrication. Hose and fitting compatibility mattered because easier integration reduces installation time and risk of leaks. Build quality and corrosion resistance were assessed to predict longevity in wet and salty conditions. We excluded universal or vague-fit units without clear Forester-specific guidance and any products that lack documented pressure or flow ratings. We also deprioritized designs that require extensive vehicle modification or custom fabrication. The final shortlist emphasizes items that balance effective thermal control with straightforward installation and reliable materials suitable for regular road and light off-road use.
Our full evaluation process is outlined in our review methodology.
FAQ
How do I know if my Subaru Forester needs a power steering cooler?
If you notice heavier steering during long drives, burning smells near the pump, or dark, foamy steering fluid, elevated temperatures may be an issue. Vehicles used for towing, frequent steep climbs, or heavy loads are more likely to experience overheating in the steering system. Monitoring fluid condition and operating temperature gives the clearest indication.
Can I install a power steering cooler on my Forester myself?
Many coolers are designed for bolt-on installation with basic hand tools, especially if the kit includes vehicle-specific brackets and fittings. However, installs that require rerouting hoses or tight-space work may be easier with a helper or professional. Always follow safe procedures for draining and refilling steering fluid and check for leaks after installation.
Will adding a cooler change steering feel or system pressure?
A properly sized cooler that is installed with correct fittings should not negatively affect steering feel or system pressure. In some cases, lower fluid temperatures can improve consistency of steering response. It is important to ensure hoses and fittings do not create undue restriction and that pressure ratings match the vehicle's hydraulic system.
Where is the best place to mount a steering fluid cooler on a Forester?
Front-of-vehicle locations with unobstructed airflow are typically most effective because they expose the core to maximum cooling air. Avoid mounting near likely debris paths or pinch points, and ensure adequate clearance from moving parts. Mounts that use factory mounting points or supplied brackets reduce intrusion and improve stability.
How often should I check or service a power steering cooler?
Inspect hoses, fittings, and the cooler core during routine maintenance intervals or after off-road use. Look for signs of leaks, corrosion, or impact damage. If the cooler has external fittings, verify they remain tight and check fluid condition when topping off or servicing the steering system.
Conclusion
Prioritize cooling capacity, proper fitment, and durable materials when choosing a power steering cooler for a Subaru Forester. The best option balances measurable temperature reduction with straightforward mounting and reliable hose connections so that steering performance remains consistent under stress. Keep in mind tradeoffs between larger cores and installation space, and choose kits that supply compatible hardware to reduce fabrication. Focusing on compatibility, pressure ratings, and corrosion resistance will deliver the most dependable outcome for long-term steering system health.
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