2012-2016 Chevrolet Cruze Vacuum Pump: Hard Brake Pedal and Oil Leaks Explained

Symptoms of a Failing Vacuum Pump

A failing vacuum pump on a Chevrolet Cruze presents several distinct symptoms, the most serious of which affects braking safety. Being aware of these signs can help you diagnose the problem before it becomes critical.

1. Hard Brake Pedal

The most common and dangerous symptom is a brake pedal that is suddenly very hard to press. This indicates a loss of vacuum assist to the brake booster. Without this assist, the force required to stop the vehicle increases dramatically, which can lead to longer stopping distances and an increased risk of a collision. 🎬 Watch: Fixing a hard brake pedal by replacing the vacuum motor This issue is often most noticeable at low speeds or when idling.

2. Oil Leaks

Oil leaking from the back of the cylinder head, where the vacuum pump is mounted, is a frequent sign of failure. Over time, the seals and gaskets within the pump can degrade, causing engine oil to seep out. If you notice oil stains on the ground under the passenger side of the engine bay or see oil residue on the pump itself, the internal seals have likely failed.

3. Hissing Noises

A hissing sound coming from the engine bay, especially when the brakes are applied, can indicate a vacuum leak. This sound is caused by air being sucked into the system through a cracked hose, a bad seal on the pump, or a crack in the pump housing itself.

4. Buzzing Noise After Engine is Off

In some cases, a failing vacuum pump or a related electrical issue can cause a buzzing noise that continues after the car is turned off. This can drain the battery overnight. This may be caused by a stuck internal relay or a faulty vacuum switch that keeps the pump running.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

The first-generation Chevrolet Cruze has a documented history of issues related to its power brake assist system.

• NHTSA Recall 13V360000 (GM Campaign #12213): This major safety recall was issued for 2011-2012 Chevrolet Cruze models equipped with the 1.4L turbo engine and automatic transmission. The recall addressed a faulty microswitch in the power brake vacuum pipe assembly that could cause an intermittent or complete loss of power brake assist. The remedy was to replace the microswitch or the entire vacuum pipe assembly. While this recall doesn't cover the pump itself, it highlights the sensitivity of the braking system to vacuum-related problems.
• TSB PI0797: This Preliminary Information bulletin addresses a hard brake pedal at startup or while idling. It points to potential causes like a restricted vent hose for the electronic vacuum pump or a faulty brake booster vacuum switch.

Buying a Used Vacuum Pump: What to Check

A used OEM vacuum pump can be a reliable and cost-effective alternative to an expensive new part. However, a thorough inspection is key to avoiding a bad part.

1. Inspect the Housing: Carefully check the entire aluminum pump housing for any cracks, especially around the mounting bolt holes and the vacuum line connections. Stress fractures can lead to vacuum leaks.
2. Check for Leaks: Look for signs of old oil residue. While some staining is normal, heavy, caked-on oil could indicate a severe past leak from the main seals. Ensure the gasket surface that mates to the engine is clean and free of deep scratches or gouges.
3. Verify Part Numbers: Match the part number on the used pump to the known OEM numbers (13390008, 13357186, 13376001, 55488984) to ensure compatibility.
4. Consider Mileage: Opt for a pump from a lower-mileage vehicle if possible. While these pumps can last a long time, wear is inevitable. A pump from a vehicle with under 100,000 miles is a safer bet.
5. Why Used OEM is a Good Choice: Used original equipment (OEM) pumps are built to GM's exact specifications for materials and performance. They often offer better longevity and a more precise fit than cheaper, new aftermarket parts, which can sometimes use lower-quality seals that fail prematurely.

Installation Guide

Replacing the vacuum pump on a 1.4L or 1.8L Cruze is a moderately difficult job that a skilled DIY mechanic can perform. Access is tight as the pump is located on the back of the cylinder head on the passenger side of the engine bay.

Basic Replacement Steps:

1. Disconnect the negative battery terminal.
2. Remove any components obstructing access, such as the engine cover or air intake ducting.
3. Carefully disconnect the vacuum hose from the pump. Be gentle, as the plastic fitting can become brittle over time.
4. Remove the mounting bolts (typically three 13mm bolts) that secure the pump to the cylinder head.
5. Gently pull the pump away from the engine. It is driven by the camshaft, so some wiggling may be required to disengage it.
6. Thoroughly clean the mounting surface on the cylinder head, removing all traces of the old gasket and oil.
7. Install the new gasket onto the replacement pump.
8. Carefully align the new pump and install it, tightening the mounting bolts to the manufacturer's specified torque.
9. Reconnect the vacuum hose and any other components that were removed.
10. Reconnect the battery, start the engine, and check for both oil and vacuum leaks. Test the brake pedal feel before driving.

Cost Comparison

The cost of replacing a Chevrolet Cruze vacuum pump can vary significantly based on the type of part used and whether you perform the labor yourself.

Frequently Asked Questions (FAQ)