Parts for your 2008 Mitsubishi Outlander-Brake booster

2008 Mitsubishi Outlander Brake Booster

Yes, the 2008 Mitsubishi Outlander is fitted with a vacuum-type brake booster. This is documented in Mitsubishi’s Factory Service Manual for the 2007–2012 Outlander (Group 35 – Brakes, Power Brake section), which details a vacuum servo/booster and check valve arrangement used across CW-series models, including 2008. The Mitsubishi ASA electronic parts catalogue for the CW Outlander also lists a “Booster, Brake” for petrol and diesel variants in this model year, confirming the part’s presence and serviceability.

On the Outlander, the brake booster’s job is to use engine vacuum to multiply pedal force so the driver doesn’t need to stomp on the pedal to stop smartly. It sits on the firewall under the bonnet, with the master cylinder mounted to its front and a one‑way check valve and vacuum hose feeding it. If the booster or its vacuum supply is crook, the brake pedal goes rock-hard and stopping distances can blow out. A leaking booster can also cause a rough idle or stalling when braking because of the vacuum leak.

There’s no routine replacement interval for the booster, but it should get a look during regular servicing of a 2008 Outlander. Sensible checks include:

• Inspecting the vacuum hose and one‑way check valve for cracks, oil contamination, or loose fits.
• Listening for a hiss around the pedal or firewall with the engine running (a tell‑tale of a diaphragm leak).
• Performing a quick function test: with the engine off, pump the pedal a few times, hold light pressure, then start the engine. The pedal should drop slightly as vacuum assist kicks in.

If replacement is needed, a competent tech will typically label and remove the vacuum line, unbolt the master cylinder from the booster, and separate the pushrod from the brake pedal inside the cabin. Depending on space, the master cylinder may be moved aside without cracking the brake lines, if the lines are opened, the system must be bled properly, and an ABS bleed procedure with a scan tool may be required. Always tighten fixings to the service manual specs and verify pedal free play and booster pushrod length as outlined in the Mitsubishi FSM. Diesel Outlanders rely on a vacuum pump for assist, so vacuum supply checks are part of the job as well.

Technical sources: Mitsubishi Motors Outlander 2007–2012 Factory Service Manual (Group 35 – Brakes, Power Brake), Mitsubishi ASA Electronic Parts Catalogue for CW-series Outlander (2006–2012) listing “Booster, Brake” for 2008 models.

Popular questions about 2008 Mitsubishi Outlander brake boosters

How can someone tell if the brake booster is failing on a 2008 Outlander?
Common signs are a very firm pedal, longer stopping distances, a hissing noise near the pedal or firewall, and sometimes a rough idle when braking. The quick start-up test (pedal drops slightly when the engine starts) is a handy driveway check.

Is it safe to drive with a bad brake booster?
It’ll usually still stop, but pedal effort skyrockets and braking performance is compromised. If there’s a vacuum leak, the engine may run poorly. It’s best to park it and get it inspected rather than risk a close call.

Do petrol and diesel 2008 Outlanders use the same booster?
Both use a vacuum booster, but vacuum supply differs: petrol models draw manifold vacuum, while diesels use a vacuum pump. Part numbers and calibration can vary by engine and VIN, so matching via the EPC or VIN lookup is the smart play.