Where to Find Genuine Hydraulic Fluid for Classic Skyline HICAS Systems (And Why ATF Is Not Always The Answer)
You are wrestling the steering wheel of your R32 Skyline in a parking lot, that HICAS light is blinking on the dash, and you suddenly realize—the previous owner probably filled the rear steering system with the wrong fluid three years ago.
Here is the thing about Nissan’s HICAS system. It stands for High Capacity Actively Controlled Suspension, and it is the rear-wheel steering setup found on everything from R32 Skylines to S13 240SXs to Z32 300ZXs . It is brilliant when it works. But when the hydraulic fluid is wrong, old, or low, the system gets cranky. The steering feels heavy. The rear wheels do not respond correctly. And finding the right fluid is not as simple as grabbing any bottle of power steering fluid off the shelf. This guide tells you exactly what fluid the HICAS system needs, where to find it, and how to avoid expensive mistakes.
TL;DR: The Nissan HICAS system uses automatic transmission fluid (ATF) that meets Nissan Matic C, D, or J specifications . Do not use standard power steering fluid or universal ATF unless it explicitly lists these Nissan specs. Red Line Synthetic Power Steering Fluid works well and is compatible with Nissan systems . Smith & Allan ATF SPIII is another solid option that lists Nissan Matic C, D, and J on its compatibility chart . The system holds about 1–2 quarts, and bleeding requires a specific procedure involving the HICAS warning light or a CONSULT diagnostic tool . If you are tired of dealing with HICAS problems, some owners delete the system entirely using a Whiteline bypass kit .
Key Takeaways:
- HICAS uses ATF, not standard power steering fluid – Look for Nissan Matic C, D, or J specifications
- Red Line Synthetic Power Steering Fluid is a trusted aftermarket option that works with Nissan systems
- Smith & Allan ATF SPIII lists Nissan Matic compatibility explicitly
- The system is separate from ATTESA – Do not confuse the rear steering system (HICAS) with the all-wheel-drive system (ATTESA)
- Bleeding is not optional – You need a helper, a way to lift all four wheels, and a clear hose to watch for bubbles
- If HICAS fails completely, Whiteline makes a bypass kit that disables the system
HICAS vs. ATTESA: Know What You Are Working On
Let me clear up one of the biggest misconceptions in Skyline ownership. HICAS and ATTESA are not the same thing .
Did you know? A huge number of owners confuse these two systems. According to a Skyline resource guide, “We cannot count how many times we see people confuse ATTESA and HICAS when talking about R32, R33, and R34 GT-Rs” .
Here is the simple breakdown:
- HICAS (High Capacity Actively Controlled Suspension) – This is your rear-wheel steering system. It is part of the steering system. It steers the rear wheels at higher speeds to improve handling .
- ATTESA – This is your all-wheel-drive system. It controls how much torque goes to the front wheels through the transfer case. It is part of the driveline .
They both have hydraulic components. They both can throw warning lights. They both use similar types of fluid. But they are completely separate systems. When you are working on HICAS, you are working on steering. When you are working on ATTESA, you are working on the transfer case and front drivetrain.
Bold safety reminder: Before you buy any fluid or start any repair, confirm which system is actually giving you trouble. A HICAS light does not mean your all-wheel drive is broken .
What Fluid Does HICAS Actually Use?
Now, here is where things get really interesting. The HICAS system is hydraulic. It uses fluid pressure to move the rear steering rack. But what fluid goes in there?
The answer is automatic transmission fluid (ATF) that meets Nissan’s Matic specifications. Specifically, you want fluid that lists Nissan Matic C, Matic D, or Matic J on the bottle .
Why ATF? Because ATF has the right viscosity and friction characteristics for the hydraulic valves and pistons inside the HICAS system. Standard power steering fluid is usually too thin and does not have the same additive package.
According to a Skyline GT-R guide, “Nissan specifies Nissan special power steering fluid for the [HICAS] control side” . That “special” fluid is essentially ATF with Nissan’s Matic approval.
Factory Fluid Options
If you want to stay purely OEM, you can buy genuine Nissan Matic fluid from:
- Nissan dealerships – Any Nissan dealer can order Matic D or Matic J
- Nissan Motorsport (NISMO) – Some NISMO parts suppliers carry OEM fluids
- Japanese parts importers – Companies like RHDJapan or Nengun can source genuine Nissan fluid
Aftermarket Fluids That Work
You do not need to pay dealership prices. Several aftermarket fluids meet Nissan Matic specifications.
Red Line Synthetic Power Steering Fluid – This is a popular choice among Skyline owners. Red Line specifically states their fluid “satisfies the service fill requirements of most auto manufacturers” including “Nissan, Lexus, Infiniti, [and] Jaguar” . It is fully synthetic, has excellent thermal stability (flash point 225°C), and works at temperatures as low as -50°C . It is also compatible with petroleum-based ATFs, so you can mix it with existing fluid .
Smith & Allan ATF SPIII – This fully synthetic ATF explicitly lists “Nissan: Matic C, D, J” on its performance levels . It is designed for “Asian and European automatic transmissions and power steering systems as recommended by the manufacturer” .
General ATF with Matic Approval – Any ATF that says “Nissan Matic D” or “Matic J” on the label will work. Avoid universal ATFs that only list “Dexron” or “Mercon”—those do not guarantee HICAS compatibility.
Comparison Table: HICAS-Compatible Fluids
| Brand/Product | Nissan Matic Spec | Fluid Type | Notes | Price Range |
|---|---|---|---|---|
| Nissan Genuine Matic D | Matic D (OEM) | Conventional ATF | Factory fill, safe bet | $15–25/quart |
| Nissan Genuine Matic J | Matic J (OEM) | Synthetic ATF | Newer spec, backward compatible | $20–30/quart |
| Red Line Synthetic Power Steering Fluid | Compatible with Nissan systems | Fully synthetic PS fluid | Excellent thermal stability, -50°C pour point | $18–25/pint |
| Smith & Allan ATF SPIII | Matic C, D, J | Fully synthetic ATF | Made for Asian vehicles, oxidation resistant | £10–15/liter (UK) |
| Generic Dexron/Mercon ATF | Not specified | Conventional ATF | NOT RECOMMENDED for HICAS | $8–12/quart |
Source: Manufacturer specifications and compatibility charts
What to avoid:
- Standard “power steering fluid” (too thin, wrong additives)
- CVT fluid (completely wrong formulation)
- Brake fluid (would destroy the seals)
- Universal ATF that does not list Nissan Matic specs
How Much Fluid Do You Need?
The HICAS system does not hold a massive amount of fluid. For a drain and refill (just replacing what comes out of the reservoir), you need about 1 quart (1 liter) .
For a complete flush (bleeding all the old fluid out of the lines and rear steering rack), you need 2–3 quarts. The exact amount depends on how much air you bleed out and how many cycles you run.
According to the Nissan HICAS bleeding procedure, “While bleeding air from power cylinders, never allow fluid level to drop below inlet port of reservoir tank” . So buy an extra quart to be safe—running the reservoir dry means starting over.
How to Bleed the HICAS System (The Right Way)
Here is where most owners mess up. You cannot just top off the fluid and call it done. The HICAS system traps air easily, and that air makes the rear steering sluggish or completely non-functional .
The official Nissan HICAS bleeding procedure requires either a CONSULT diagnostic tool or using the HICAS warning light to put the system into self-diagnosis mode .
What You Will Need
- 2–3 quarts of Nissan Matic-compatible ATF
- A clear vinyl hose that fits over the bleeder valves
- A container to catch old fluid
- A way to lift the vehicle so all four wheels can spin freely
- A helper to turn the steering wheel and watch gauges
- Safety stands (never work under a car supported only by a jack)
Method 1: Using a CONSULT Tool (Easier)
This is the professional method. A CONSULT or compatible scan tool can activate the HICAS pump and cycle the system.
- Lift and support the vehicle so all four wheels can spin freely
- Connect the CONSULT tool to the diagnostic connector
- Start the engine
- On the CONSULT, navigate: HICAS → ACTIVE TEST → SIMULATED DRIVE
- Connect clear hose to the right and left power cylinder bleeder valves, with the other ends in a container of clean fluid
- Operate engine at speeds greater than 2000 RPM and turn steering wheel 180° to the right
- Loosen the right power cylinder bleeder valve to bleed air, then tighten
- Return steering wheel to neutral
- Repeat turning to the left
- Continue until no air bubbles appear in the hose
Method 2: Using the HICAS Warning Light (No Special Tool)
If you do not have a CONSULT tool, you can put the system into self-diagnosis mode using the warning light.
- Lift and support the vehicle so all four wheels can spin freely
- Turn ignition OFF
- Place shift lever in Park (automatic) or Neutral (manual)
- Turn ignition ON and immediately start the engine
- Within 10 seconds of starting:
- Turn steering wheel from left to right at least 20° from neutral position five times or more
- Depress foot brake pedal at least five times
- Connect clear hose to bleeder valves with containers
- Place steering wheel within 10° of neutral and confirm rear wheels turn left and right alternately
- Operate engine at idle and turn steering wheel 180° to right
- Loosen right bleeder valve, then tighten
- Return to neutral and repeat to the left
- Continue until no bubbles appear
- Turn ignition OFF to exit self-diagnosis
Bold safety reminder: Throughout the bleeding process, “never allow fluid level to drop below inlet port of reservoir tank” . If the reservoir runs dry, you pull more air into the system and have to start over.
A Note on HICAS Delete Kits
Some owners decide they are done with HICAS entirely. If the system keeps failing or you want more predictable handling at the limit, you can delete it.
Whiteline makes a HICAS disabling unit (KSR204) that includes a hydraulic fluid bypass pipe . According to Whiteline, “Disabling the HICAS unit has been proven to provide greater vehicle stability and more predictable handling at the limit, allowing faster lap times” .
The kit fits:
- S13 (180SX, Silvia, 240SX)
- Z32 (300ZX)
- R32 (Skyline GT-R, GTS, GTS-4)
If you go this route, you do not need to worry about HICAS fluid ever again. But you also lose the rear steering capability that makes the Skyline unique.
Interactive Chart: HICAS Fluid Compatibility
The chart below shows which fluid types are safe for your Skyline’s HICAS system and which will cause damage. Green is safe, yellow is questionable, and red will destroy your system.
🔧 HICAS Fluid Compatibility Chart – Nissan Skyline R32, R33, Z32, S13
Compatibility ratings based on Nissan specifications and owner-reported experiences. Green = safe, Yellow = use with caution, Red = do not use.
How to read the chart: Nissan Matic D/J fluids score a perfect 10. Red Line and Smith & Allan score 9—excellent aftermarket choices. Generic Dexron/Mercon ATF scores a 5—it might work but is not guaranteed. Standard power steering fluid scores a 3—it is too thin for HICAS. Brake fluid or CVT fluid scores a 0—never put these in your HICAS system.
FAQ – Your HICAS Fluid Questions Answered
1. What is the difference between HICAS and ATTESA fluid?
HICAS is rear-wheel steering and uses ATF meeting Nissan Matic C/D/J specs. ATTESA is all-wheel drive and uses Nissan special power steering fluid in the hydraulic control side and Type D fluid in the transfer case . They are completely separate systems with different fluid requirements.
2. Can I use standard power steering fluid in HICAS?
No. Standard power steering fluid is too thin and lacks the correct friction modifiers. HICAS was designed for ATF. Using power steering fluid can cause sluggish response, seal damage, and system failure. Red Line makes a synthetic power steering fluid that works, but it is specifically formulated to meet Nissan requirements .
3. How often should I change HICAS fluid?
Every 30,000–50,000 miles, or whenever you notice heavy steering or a blinking HICAS light. The fluid absorbs moisture over time and loses its effectiveness. If the fluid looks dark brown or black, change it immediately.
4. Where can I buy genuine Nissan Matic fluid?
- Your local Nissan dealership parts counter
- Nissan Motorsport (NISMO) distributors
- Online JDM parts specialists like RHDJapan, Nengun, or Blackhawk Japan
- eBay (be careful of counterfeits—buy from reputable sellers)
5. What is the Whiteline HICAS delete kit?
The Whiteline KSR204 is a bypass kit that disables the HICAS rear steering system. It includes a U-shaped hydraulic bypass pipe and a disabling unit . It is popular among track drivers because it makes the car more predictable at the limit. Once installed, you do not need to maintain the HICAS hydraulic system anymore.
6. My HICAS light is on. Do I need new fluid?
Maybe. The HICAS light can indicate low fluid, air in the system, a failed pump, or an electronic sensor issue. Start by checking the reservoir level and condition. If the fluid is low or looks burnt, change it and bleed the system . If the light stays on, you may need diagnostic scanning.
7. Can I mix different brands of ATF in HICAS?
Yes, as long as both meet Nissan Matic D or J specifications. Most synthetic ATFs are compatible with conventional fluids. However, for best results, do a full flush instead of just topping off. Red Line notes their fluid is “compatible with petroleum power steering fluids and ATFs” .
8. How do I know if HICAS is working correctly?
With the car on a lift (all four wheels off the ground), start the engine and turn the steering wheel. The rear wheels should steer slightly in the opposite direction at low speeds. You should also see the rear wheels return to center when you straighten the wheel. No movement means the system is not working.
Are you running HICAS on your Skyline or did you delete it? What fluid have you had the best luck with? Drop your experience in the comments below—your advice could save another owner from a costly mistake. And if this guide helped you keep your HICAS alive, share it with a fellow Skyline owner who is chasing that blinking dash light.
Keep those rear wheels steering. 🚗🔧🛞
