Parts for your 2015 Mitsubishi Asx-Brake master cylinder

2015 Mitsubishi ASX Brake Master Cylinder

Based on Mitsubishi technical sources, the 2015 Mitsubishi ASX is fitted with a conventional hydraulic brake master cylinder. The Mitsubishi ASX/RVR/Outlander Sport Workshop Manual (2010–2017, Group 35A – Hydraulic Brakes) details a tandem master cylinder mounted to a vacuum brake booster, feeding the ABS/ASC hydraulic unit. The Mitsubishi ASA Electronic Parts Catalogue lists the master cylinder under Section 35 (typical Mitsubishi p/no family 4605Axxx for ASX variants). These references confirm the brake master cylinder is absolutely relevant to the 2015 ASX.

On the ASX, the brake master cylinder converts the driver’s foot pressure into hydraulic pressure, sending fluid to two separate brake circuits for safety. Working with the booster and ABS/ASC modulator, it ensures strong, consistent braking and even pressure distribution. Inside are precision bores, pistons and seals, plus a reservoir that holds the fluid the system relies on to stay responsive and corrosion-free.

• Common clues it needs attention: a soft or sinking pedal at the lights, fluid loss without obvious external leaks, a brake warning lamp, or brake feel that’s inconsistent between stops.
• Visual checks: look for dampness around the master cylinder-to-booster join, perished hoses, and dark or contaminated fluid in the reservoir.

For servicing, it’s smart to inspect the master cylinder at every service and replace brake fluid every two years or 40,000 km (whichever comes first). Use the brake fluid grade shown on the reservoir cap and owner’s manual (DOT 3 or DOT 4 as specified). Keep the cap area clean before opening, don’t mix incompatible fluids, and avoid getting fluid on paint.

1. Replacement overview: depressurise the system, label and disconnect lines, unbolt the unit from the booster, and bench-bleed the new master cylinder before fitting.
2. Refit with new sealing washers or grommets where required, torque lines carefully to avoid flare damage, then bleed the full system. Many ASX models benefit from an ABS service-bleed routine using a scan tool to purge the modulator.
3. Finish with a road test on a quiet stretch, confirm a firm pedal, and recheck for weeps after a short drive.

If a spongy pedal persists after bleeding, a professional pressure test can confirm internal bypassing. Given brakes are a safety system, getting a qualified tech to handle diagnosis and bleeding is the best bet for peace of mind.

FAQ: What brake fluid should be used in a 2015 Mitsubishi ASX?
Most 2015 ASX models specify DOT 3 or DOT 4 glycol-based fluid, check the reservoir cap and owner’s manual for the exact grade. DOT 4 is commonly used in Australia and New Zealand for its higher boiling point.

Never use silicone DOT 5. Replace fluid every two years to keep corrosion and moisture at bay, and always use fresh, sealed containers.

FAQ: How can someone tell if the ASX master cylinder is failing?
Signs include a pedal that slowly sinks under steady pressure, a long or inconsistent pedal, fluid level dropping without visible external leaks, or dampness where the cylinder meets the booster.

Confirm by holding firm pedal pressure with the engine running—if it steadily drops, there may be internal seal bypass. A proper inspection and pressure test will nail it down.

FAQ: Is programming needed after replacing the master cylinder on an ASX?
The master cylinder itself doesn’t require programming. However, many ASX variants need an ABS service-bleed procedure with a scan tool to purge air from the modulator after installation.

Clear any ABS/ASC fault codes, verify pedal feel, and road test. Always recheck for leaks and fluid level after the first drive.