This article will discuss some important VW brake rotor replacement information. How do you know if your VW brake rotors need to be replaced? How to prevent premature VW brake rotor warping and tech tips on how to ensure a successful VW brake rotor replacement.
How Do You Know If Your VW Brake Rotors Need to Be Replaced?
The front brake system performs roughly 60-80% of the braking. This is because most of the vehicles weight or inertia is loaded and shifted on the front. This is typically why the front braking system is always larger than the rear and why the front brake rotors and brake pads will need to be replaced more frequently. A telling sign of needing new front VW brake rotors is indicated by the brake warning light being illuminated on the dashboard instrument cluster. Most front VW brake pads have wear sensors built right into the brake pad material. This wear sensor triggers the brake warning light to illuminate on the dashboard instrument cluster. With the brake warning light illuminated, this means the brake pads are worn and at the end of their life cycle. Due to the higher performance expectations of today’s modern cars your brake rotors typically should also be replaced with the brake pads. If you are experiencing the brake warning light being illuminated your VW brake rotor and brake pad should be replaced right away in order to restore and maintain proper road safety and braking performance. If you are not sure if the front of your vehicle has brake wear sensors a second way to see if you need new brake rotors is to visual inspection the condition of your brake rotors and brake pads. A third indication of worn front VW brake rotors and pads is a grinding metal-on-metal sound coming from the front of the car every time you depress the brake pedal. When the VW brake pad material has been fully exhausted, contact with the VW brake rotor will cause this type of grinding sound. You should seek an VW brake replacement service immediately when you hear this grinding noise.
An indication of needing new rear VW brake rotors can also be identified like the front brake system. Some rear brake systems are equipped with rear brake wear sensors. If your rear brake pads do have a wear sensor you should experience a brake warning light being illuminated on the dashboard instrument cluster. This indicated you would need to replace your rear brake rotors and brake pads. If your rear brake system does not have brake wear sensors you will not experience the VW brake pad warning light on the instrument cluster dash area. You will need to do a visual inspection for the condition of your brake rotors and brake pads. The main indication of worn rear VW brake rotors is a grinding metal-on-metal sound coming from the rear of the car every time you depress the brake pedal. When the VW brake pad material has been fully exhausted, contact with the VW brake rotor will cause this type of grinding sound. You should seek an VW brake replacement service immediately when you hear this grinding noise.
The above symptoms usually occur when there is around 40,000 to 80,000 miles on your brake pads and rotors. Another symptom that VW brake rotors need replacing is vibration felt through the brake pedal or steering wheel while pressing on the brake pedal. This is an indication that the VW brake rotors are warped and have worn thin, due to age or overheating caused by some other brake component failure.
How Can You Prevent VW Brake Rotor Replacement Problems?
For the best brake performance new VW brake rotors should not be used with old brake pads (visa versa). Always replace your new VW brake rotor set with a new set of brake pads! Why? The surface area of a new VW brake rotor must meet a flat/smooth brake pad, free from imperfections. The face of old brake pads is imperfect having a glazed and scored surface instead of a flat/smooth surface. Using old brake pads with imperfections will not allow the new VW brake rotors to bed in properly. This will result in weak braking performance and VW brake system squealing and noises. Therefore, always install new brake rotors when installing new VW pads. That is why Blauparts offers a full range of VW brake rotors and pads to ensure successful brake replacement.
Bedding New VW Brake Rotors
It is important to know that new VW brake rotors along with brake pads should be bedded in carefully. When new brakes are installed, you need to go easy for the first 100-200 miles. Some customers were perplexed after installing a new set of VW brake rotors and brake pads because they were experiencing squealing. They have commented that their brake pedal "just doesn't feel quite right." What's causing this?
Typically, all replacement brake rotors after being manufactured are stored and shipped with an oil or cosmoline applied to the brake rotor face. This is done to prevent rust during storage and transport. Often, when it comes time to install the VW brake rotor, the rushed mechanic doesn't take the time to remove this residue believing it will "burn off" right after you apply the brake pedal a few times. It is important to understand that if oily residue is left on the brake rotor face you will potentially ruin your new brake rotors and pads. Why? Because the oil residue will embed itself on the new brake pads and become "glazed." This causes them to "slip" instead of "bite" into the new brake rotor face. The glazed brake rotor or brake pads generate more heat when slipping and do not allow for the proper brake rotor and brake pad break-in conditions to take place. This condition will cause the brakes to feel weak when you push on the pedal.
Bedding in our VW brake rotors and brake pads consists of a simple braking sequence. While driving down a side road perform the braking sequence from 60 down to 15 mph with a medium pedal compression. Perform this braking sequence three times consecutively allowing around 60 seconds in between each stop. Once this is done allow the brakes to cool. Allowing the car to cool for around 30 minutes should be enough to cool the brake system. This is an initial brake bedding sequence and should allow for a good brake pedal feel and bit. Once the brakes have cooled you can continue with your normal driving conditions and characteristics. After about 15-20 minutes of normal driving conditions the proper brake bedded performance can be had.
Tips on How to Ensure Correct VW Brake Rotor Replacement.
Are you experiencing pulsing through the brake petal when applying the brakes? Or a shuddering vibration through the car when braking? Brake replacement is often conveyed as a simple service. Some chain "we-fix-everything-for-less" repair shops focus on turn around – rather than the quality of a brake job. Just slap on a new pair of rotors and pads? Not necessarily. Assuming it's as simple as warped rotors could end up costing you more money in the long run. Why?
How to Prevent Premature VW Brake Rotor Warping
INSPECTION Road conditions, age, and resulting rust and pitting affect a lot more than just the rotors and pads. Brake rotors and pads are just two parts of a comprehensive braking system. The braking system's main components include: Brake rotors, brake pads, brake hoses, calipers, caliper carrier brackets, caliper guide pins and boots, brake pad retaining clips, hoses, wheel hubs, brake fluid, brake master cylinder, etc. Spending the extra time and money to properly inspect and diagnose the root cause of brake problems before diving into repair is imperative. Some owners just throw a new pair of rotors and pads on, only to have their symptoms return shortly thereafter. Make sure you choose a reputable ASE certified mechanic that is familiar with your VW model.
Before investing in brake repair be sure to properly inspect the following brake components:
- Caliper piston, which is located under the caliper piston boot. Look for any pitting or rust. If you note any pitting or rust behind the boot, the caliper should be rebuilt or replaced.
- Check the brake hoses for any signs of age, splitting or being collapsed.
- Confirm the integrity of your brake fluid, it's color and age.
- Confirm brake master cylinder functions. Example: Use an infrared heat gauge to look at the temperature of each rotor after a test drive. A temperature difference often points to an underlying issue on a side or corner that may require a more detailed inspection.
- Rusted and dirty caliper guide pins
- Brake pad retaining clips
- Brake rotor to wheel hub cleanliness
- Brake carrier bracket to brake pad mating areas free of rust and road debris.
SURFACE PREPARATION - Common premature brake issues after brake rotor and pad replacement are usually caused because one of the following areas were not properly cleaned. Be sure that they are free of all debris, rust, grooves, pitting, sharp edges, and are just like new:
- Wheel hub [IMAGE 1]. If the rusting and pitting is horrible the hub should be replaced. If it isn't replaced, the new brake rotors won't ride 100% true. Use a brake hub and rotor True Gauge Tool to confirm correct brake rotor alignment.
- Brake pad to caliper mating surfaces, the caliper piston, and outside of caliper [IMAGE 2, IMAGE 3]. This allows the new pad to ride true to the caliper piston.
- Brake caliper pins [IMAGE 4].
- Brake pad to carrier bracket mounting points / contact points, where the pad slides on carrier bracket [IMAGE 5, IMAGE 6]. Usually a medium grit scotch brite pad is enough to achieve smooth surfaces. If pitting is bad a minor file might be needed.
PICTURED EXAMPLE: 1 owner 1997 VW A4 Quattro with approximately 100,000 miles on it. This car was well cared for with receipts for its scheduled service and maintenance history that stacked roughly two inches tall. Even though this car was well maintained it has spent all its life in the Midwest snowbelt. This area experiences long winters with the roadways coated in salt and a liquid calcium chloride and magnesium chloride. This is extremely rough on your VW brake rotors and can amplify the deterioration of your brake rotors and the related brake components. If you do live in a snow belt that sees a lot of road salts you can minimize the deterioration of your brake components by specifically visiting the car wash a little more often. The best way to minimize this brake system deterioration is to use a pressure washer to specifically pressure wash the brake rotors and related brake components through the wheel area. Despite putting effort forth in minimizing the brake system wear the following steps can be taken or closely examined during your new VW brake rotor and brake pad service. Service records indicated this was the 2nd brake service performed since this cars date of sale. Note the debris, rust, grooves, pitting, sharp edges. It's important to take the time to properly clean all contact areas and make them just like new. Taking the time to properly clean these surfaces can greatly minimize premature brake system issues after a new brake rotor and brake pad replacement.
[IMAGE 1] VW wheel hub to brake rotor cleanliness.
Clean the wheel hub the brake rotor mounting surface so that is clean and free of any rust pitting and road debris. If the rusting and pitting is horrible the hub should be replaced. If it isn't replaced, the new VW brake rotors won't ride 100% true. Use a brake hub and rotor True Gauge Tool to confirm correct VW brake rotor alignment. If you do not clean this area your new brake rotor will not spin true to the hub and brake caliper resulting in prematurely warped brake rotors
[IMAGE 2] Inner VW brake pad to caliper piston mating surface.
The caliper piston should be free from rust and any uneven surfaces. This will allow your new inner brake pad to mount true to the caliper piston. If the caliper piston surface is not clean and true, the new brake pad will not engage the brake rotor evenly. This will result in a brake pad that might not completely disengage from the brake rotor surface. If the brake pad continues to engage your new brake rotor unevenly this will cause the brake rotor to experience uneven or excessive temperatures. This will result in prematurely glazed brake rotors and pads, brake squealing and warped brake rotors.
[IMAGE 3] Outer VW brake pad to caliper piston mating and mounting surface.
The outer caliper to brake pad mounting surface should be free from rust, debris and any uneven surfaces. This will allow your new brake pad to mount true to the outside area of the brake caliper. If this surface is not clean and true, the new outer brake pad will not engage the brake rotor evenly. This will result in a brake pad that will not completely disengage from the brake rotor surface. If the brake pad continues to engage your new brake rotor unevenly this will cause the brake rotor to experience uneven temperatures. This will result in prematurely glazing of the brake rotors, brake noises and warped brake rotors.
Also, when cleaning the brake caliper piston, you will want to confirm that the brake caliper piston compressed evenly and smooth without binding. Confirm you had no binding while sliding the piston back into the brake caliper piston bore. If the caliper piston does bind you will want to replace the brake caliper. A sticky brake caliper piston is typically caused by a corroded or rusted piston and piston bore. Typically, this is because of moisture in the brake fluid system. If you choose to use a sticky brake caliper you will experience excessive brake pad to brake rotor temperatures due to the caliper not allowing the brake pads to fully disengage the brake rotor. This will result in poor brake system performance leading to glazed brake rotors, glazed brake pads, brake noises, and warped brake rotors
Confirm that the brake caliper piston boot that surrounds the piston is nicely sealed. You will also want to confirm that it is not torn. If you do have a torn brake caliper piston boot this will allow moisture to get into the brake caliper resulting in corrosion and rust. If your brake caliper piston boot is torn more than likely you will want to replace the brake caliper due to the piston and brake caliper internals being exposed to moisture and corrosion.
[IMAGE 4] VW brake caliper pin cleanliness.
Clean the brake caliper mounting pins so they are clean and free of any rust pitting and road debris. If the rusting and pitting is bad the brake caliper mounting pins should be replaced. After you have cleaned your brake caliper mounting pins test and confirm that they evenly slid in and out of the brake caliper carrier bracket mating areas. If it does not slide evenly and smooth the caliper pins, caliper pin bushings or brake carrier bracket should be replaced. If you cannot confirm the brake caliper pins move freely this can cause the caliper to apply uneven pressure to the brake rotor resulting in prematurely glazed brake rotors and brake pads, brake noises and warped brake rotors.
[IMAGE 5 and 6] VW brake pad to carrier bracket mounting points and contact points.
You will want to clean the brake pad to carrier bracket mounting areas so that they are free from rust and debris. Usually a medium grit conditioning pad is enough to achieve smooth surfaces. If pitting is bad a minor file might be needed. Once you have this area clean you will want to confirm your new brake pads slide back and forth through the brake carrier bracket mounting area. Having a clean carrier bracket will allow your brake pads to be fully disengages when you are not applying your brake pedal. If the brake carrier bracket is not cleaned properly you can experience some brake pad binding in the carrier bracket area. This could cause an area of the brake pad to continue its brake rotor engagement when not intended. This can cause the brake rotors to experience uneven temperatures resulting in prematurely glazed brake rotors and brake pads leading to brake squealing and warped brake rotors.
[IMAGE 7] Apply a light amount of grease to various brake components.
A light amount of grease can be applied to the brake caliper piston, brake caliper carrier bracket pins, and the brake caliper carrier bracket to brake pad mounting/sliding areas. This can be done lightly confirming you do not have excessive amounts of grease getting on the brake pad compound or brake rotor disc mating surfaces. This light amount of grease can be rubbed into these surfaces to minimize the corrosion and rusting process.
When greasing the hub, you can apply anti-seize. This will also help slow down the corrosion and rusting process between the brake rotor and hub mounting areas.
BLAU® HCC VW Brake Rotors - High Carbon Chromium
Our brake rotors are quality performance brake rotors with a higher carbon cast iron alloy with chromium (Cr). Our brake rotors are racetrack tested and great for the street! An excellent choice for normal everyday driving comfort, longevity, and aggressive driving.
BLAU® HCC Brake Rotor Features:
- Silver anti corrosion coating slows down rotor deterioration and allows for a clean attractive look through the wheels.
- 'Ready-To-Install' - No messy clean up with harmful chemicals. No need to clean oil or cosmoline off the brake rotor.
- The perfect formulation of high carbon cast iron alloy with chromium (Cr) material provides higher resistance to distortion and thermal cracking.
- Optimal thermal heat dissipation results in shorter stopping distances and improved driving confidence.
- Cooler brake rotor temperatures mean less brake fade, shorter stopping distances, improved brake pedal feel and driving confidence.
Performance BLAU® HCC VW Brake Rotors are superior in design compared to others. We performed field testing at Road America racetrack to test and verify our brake rotors stopping performance. Comparing our brake rotors to other popular brake rotors in racetrack conditions has resulted in a reduction in rotor temperature at key track braking points allowed for an average drop from 360° to 200° C! This improvement in heat dissipation and braking efficiency allows our HCC brake rotors to withstand extreme braking conditions, guaranteeing an extended rotor life, preventing premature rotor warping. They were also tested in everyday street conditions from -25°F to +90°F. Our HCC brake rotors offer no unnecessary braking noises in weird weather conditions and are an excellent option for individuals who want instilled driving confident and an excellent OE fitment and look.
During demanding conditions, brake rotors can reach temperatures of 800° C or more. The result is high temperatures and gas emissions developing on the brake rotor, primarily because of the bonding materials between the brake rotors and brake pads. There is then a decrease in the coefficient of friction with the result known as brake fading. Uniform and continuous dissipation of these gas emissions between the rotor and a higher quality grade rotor casting can helps prevent brake fading. Less brake fade means a decrease in the force required to depress the brake pedal, a plus in safety and brake rotor longevity!
Some brake rotors use unknown casting materials, not allowing for the even and continuous dissipation of brake heat and gas emissions evenly through the entire brake rotor surface. Irregular gas dissipation with poor-quality casted brake rotors decrease brake friction and adversely affects braking efficiency. Over time, this inconsistent heat and gas dissipation caused when the brake pad surface compresses onto a brake rotor face can cause the brake rotors to glaze and eventually create scoring, glazed and stress cracks in the brake rotor casting. These imperfections can weaken the brake rotors performance causing premature failure and warping.