Parts for your 2017 Subaru Forester-Brake fluid

2017 Subaru Forester brake fluid — what it does and how to look after it

Brake fluid is absolutely relevant to the 2017 Subaru Forester. The model uses a fully hydraulic braking system with ABS/ESC that depends on glycol-ether brake fluid. According to the 2017 Subaru Forester Owner’s Manual (Maintenance and Service section), the system is specified for DOT 3 or DOT 4 brake fluid. Subaru’s Warranty and Maintenance Booklet for this model also lists periodic brake-fluid replacement as a scheduled service item.

In a Forester, brake fluid transfers pedal pressure to the callipers, lets the ABS and stability control modulate braking precisely, protects internal components from corrosion, and lubricates seals. It needs a high boiling point so the brakes stay confident on long downhill runs, towing, or in summer heat.

Because it’s hygroscopic (absorbs moisture), brake fluid slowly takes on water through hoses and seals. As water content rises, the boiling point drops and corrosion risk goes up. That’s why Subaru includes brake-fluid changes in routine servicing, not just as a fix for faults.

Recommended practice for a 2017 Forester:

• Fluid type: Use high-quality DOT 3 or DOT 4 meeting FMVSS No. 116. Subaru specifies DOT 3/4 for this model. Do not use silicone-based DOT 5.
• Service interval: Replace approximately every 30 months (or around 45,000–50,000 km), as outlined in Subaru service schedules. Shorten the interval if driving in humid climates, on steep terrain, or when towing.
• Checks: Inspect the reservoir level and fluid condition during regular services. Under the bonnet, the reservoir sits near the firewall. The level should stay between MIN and MAX, frequent top-ups point to a leak or pad wear that needs attention.
• Quality control: Dark, murky fluid or a spongy pedal are signs it’s time to flush. A moisture test above about 3% water content warrants replacement.
• Care: Clean around the cap before opening, use fluid from sealed containers only, avoid spills on paint, and refit the cap tightly. A proper pressure or vacuum bleed—and cycling the ABS with a scan tool where required—delivers the best result.

Sticking with Subaru’s DOT 3/4 spec and timely changes keeps pedal feel firm, braking distances consistent, and ABS/ESC working as designed—exactly what a Forester owner expects on Kiwi and Aussie roads.

Popular questions

What brake fluid does a 2017 Subaru Forester use?
Subaru specifies DOT 3 or DOT 4 glycol-ether brake fluid for the 2017 Forester. Many owners choose DOT 4 for its higher boiling point, but either DOT 3 or DOT 4 that meets FMVSS No. 116 is suitable. Avoid silicone-based DOT 5.

How often should the brake fluid be changed?
Plan on replacing the brake fluid about every 30 months (roughly 45,000–50,000 km), as per Subaru’s scheduled maintenance. If you drive in hilly areas, tow, or live in humid conditions, testing and changing it a little earlier is smart.

Can DOT 3 and DOT 4 be mixed in a Forester?
DOT 3 and DOT 4 are compatible and can be mixed for an emergency top-up, but performance defaults to the lower spec. The best approach is to flush with fresh fluid of the intended grade to maintain consistent pedal feel and high boiling points.