Brake Pulling

Brake pulling refers to a condition where a vehicle veers to the left or right instead of tracking straight under braking. This typically indicates an imbalance in braking force between the left and right wheels—a critical safety issue that demands immediate inspection.

Core Causes: Why Does It Pull? 

Hydraulic Pressure Imbalance (Hydraulic Issues)

Stuck Caliper: A rusted caliper piston or seized slider pins on one side will cause sluggish response and inadequate braking force, causing the car to pull towards the side with stronger braking power. 

Clogged or Pinched Brake Hose: An ageing, deteriorating inner brake hose lining or an externally pinched hose restricts hydraulic fluid flow, reducing braking performance on that particular wheel. 

Brake Pad Issues (Friction Material Issues)

One-Sided Oil Contamination: Leaks from engine oil, brake fluid, or grease onto the brake disc or pad on one side will drastically reduce its friction coefficient.

Mismatched Brake Pad Materials: Using different brands, unevenly worn pads, or differing friction compounds between the left and right sides. 

Uneven Brake Disc/Drum Condition 

A brake disc on one side with deep grooves, heavy corrosion, or excessive wear compared to a relatively fresh disc on the other side creates a disparity in friction.

Mechanical Linkage Failure 

Suspension/Wheel Alignment Deviation: Even if the brakes are functioning properly, incorrect wheel alignment (or uneven tyre wear) can amplify lateral forces during braking, causing the vehicle to veer to one side.

How to Diagnose and Troubleshoot?

Diagnosis Through Driving: 

Pulls only under braking: This almost certainly points to an imbalance within the braking system.

Pulls during normal cruising as well: Likely caused by misaligned wheels, uneven tyre pressures, or worn suspension components (such as lower arm ball joints).

Physical Inspection (Requires a Hoist):

Check Caliper Operation: Spin the wheels by hand and check for equal rotational resistance on both sides. If a caliper is sticking, that wheel will feel significantly heavier to turn.

Compare Brake Pad Wear: Check the pad thickness on both sides. If one side is noticeably thinner than the other, it typically points to seized slider pins or a sticking caliper piston on that side. 

Check for Signs of Fluid Leakage: Inspect around the calipers for any signs of brake fluid seepage.

Repair and Rectification Strategies

Thorough Cleaning and Lubrication: Most pulling issues stem from sticking caliper slider pins. Dismantle the caliper, thoroughly clean and re-grease the slider pins, and inspect the piston dust boots. This alone resolves up to 70% of brake pulling cases. 

Replace Brake Pads/Discs (Must Be Replaced in Pairs): Remember: Brake components must always be replaced in pairs across the same axle! Even with the exact same part, pads with different wear levels exhibit different friction properties. Replacing in pairs is mandatory to maintain balanced braking power across both wheels. 

Clean Disc and Pad Surfaces: If oil or grease contamination is found on a disc, clean it thoroughly with dedicated brake cleaner. If the friction material itself has been soaked in oil (especially on disc brakes), the brake pads must be replaced immediately; cleaning only the surface will not restore braking power once oil has penetrated deep into the pad compound.

Wheel Alignment: Once braking system issues are ruled out, be sure to carry out a four-wheel alignment. Braking places immense load on the chassis, amplifying even minor suspension misalignments.

Key Servicing Reminders

Avoid Single-Sided Repairs: If one caliper fails, inspect the opposite side as well, or better yet, service both sides concurrently.

Pay Attention to Brake Hoses: On cars over ten years old experiencing persistent brake pull, check if the flexible brake hoses have collapsed or degraded internally—a common hidden culprit behind braking faults in older vehicles.