Parts for your 1987 Mitsubishi Pajero-Brake master cylinder

1987 Mitsubishi Pajero brake master cylinder

Yes, the 1987 Mitsubishi Pajero is fitted with a brake master cylinder. Technical references back this up: the Mitsubishi Pajero/Montero 1982–1991 Factory Service Manual (Brake section) specifies a tandem-type master cylinder working with a vacuum booster, and the Mitsubishi ASA electronic parts catalogue lists master cylinder assemblies applicable to 1987 Pajero variants (commonly referenced part numbers for that era include MB555343 and MB534517, varying by engine, RHD/LHD and trim). So, the brake master cylinder is absolutely relevant to servicing and repairs on this model.

On a 1987 Pajero, the brake master cylinder is the heart of the hydraulic system. Press the pedal and it converts that foot effort into hydraulic pressure, feeding two separate circuits (front and rear) for safety. The reservoir holds glycol-based brake fluid, and internal seals and pistons create and hold pressure so the 4WD pulls up straight and confidently, whether it’s on bitumen or a corrugated back road.

As part of regular servicing, it pays to check the master cylinder for external seepage at the rear seal (where it meets the booster) and around the line ports, monitor fluid level and colour, and flush the fluid every two years. Old fluid absorbs moisture, which drops boiling point and invites corrosion that can score the bore and shorten seal life. DOT 3 is period-correct, and DOT 4 is commonly used today, stick with glycol-based fluid and never mix with silicone DOT 5.

If replacement is on the cards, bench-bleed the new cylinder before fitting to purge trapped air, protect paintwork from fluid, and confirm pedal free play and booster pushrod clearance per spec. After installation, bleed the system methodically—typically starting at the wheel furthest from the master and working closer. Many Pajeros of this era run a load-sensing proportioning valve on the rear, ensure it’s in the proper position for bleeding as outlined in the workshop manual. A good test drive should give a firm, consistent pedal with no creep at lights. Any sponginess, pull, or warning lamp needs another look for trapped air or leaks.

• Common signs of a tired master: sinking pedal, fluid loss with no external leaks, dark/contaminated fluid, uneven braking feel.
• Helpful tips: use fresh, unopened fluid, clean around the reservoir before opening, torque flare nuts snugly to avoid weeps, and if in doubt, get a qualified tech involved.

FAQs

What brake fluid should be used in a 1987 Pajero?
Glycol-based DOT 3 or DOT 4 is suitable. Don’t use silicone DOT 5. For a full flush, many home mechanics allow around a litre to ensure clean fluid at all four calipers/wheel cylinders. Replace fluid every two years or sooner if it looks dark.

How can someone tell if the master cylinder is failing?
Look for a pedal that slowly sinks at a stop, a spongy feel that won’t bleed out, fluid loss into the brake booster area, or a brake warning lamp. If hoses, calipers and wheel cylinders are dry and the pedal still fades, the master’s internal seals may be bypassing.

Does a 1987 Pajero have ABS?
Most 1987 Pajeros were non-ABS, so bleeding is straightforward. In the rare case an early ABS system is fitted, follow the ABS-specific bleed procedure in the service manual to avoid trapping air in the modulator.