Complete Guide: How to Bleed Brembo Brakes on Subaru STI
Table of Contents:
- Introduction
- Tools and Equipment Required
- Checking Brake Fluid Level
- Starting with the Caliper Furthest from the Master Cylinder
- Bleeding Procedure for Inner Bleed Nipple
- Bleeding Procedure for Outer Bleed Nipple
- Moving to the Next Caliper
- Torquing the Bleed Nipples
- Troubleshooting: Snapped Off Bleed Nipples
- Conclusion
Article:
Introduction
In this article, we will discuss the process of bleeding the brakes on an STI, both front and rear. Brake bleeding is an essential maintenance task that ensures the proper functioning of the braking system. We will guide you through the steps, highlighting the tools and equipment required and sharing important tips along the way.
Tools and Equipment Required
Before starting the brake bleeding procedure, it is important to gather all the necessary tools and equipment. You will need:
- 11 mm wrench/spanner
- 7/16-inch socket
- Large ratchet
- Short extension
- Screwdriver (for opening rubber caps on bleed nipples)
- Safety glasses
- New brake fluid (compatible with your vehicle's specifications)
- Clear hose or vacuum hose
- Brake bleed bottle or similar container
- Rag or cloth for cleaning spills
Checking Brake Fluid Level
The first step in bleeding the brakes is to check the brake fluid level. It is crucial to ensure that the fluid level is at or below the maximum line. If needed, top up the fluid to the maximum level. This is important to maintain the integrity and effectiveness of the braking system.
Starting with the Caliper Furthest from the Master Cylinder
To begin the bleeding procedure, start with the caliper that is furthest away from the master cylinder. In the case of a right-hand drive vehicle, this would be the left rear caliper. It is essential to follow this sequence to ensure proper bleeding and avoid introducing air into the system.
Bleeding Procedure for Inner Bleed Nipple
The calipers used in the STI have two bleed nipples - one inner and one outer. It is important to bleed the inner nipple first. Attach the clear hose to the nipple, making sure it is securely in place. Instruct your assistant to pump the brakes while you open the bleed nipple. Observe the fluid flow through the hose and look for any air bubbles. Continue this process until you see clean fluid without any air bubbles.
Bleeding Procedure for Outer Bleed Nipple
Once you have completed bleeding the inner bleed nipple, move on to the outer bleed nipple of the same caliper. Repeat the same process as before, ensuring that no air bubbles are visible in the fluid. Properly bleed the outer nipple to ensure a complete brake fluid exchange.
Moving to the Next Caliper
After bleeding the caliper farthest from the master cylinder, proceed with bleeding the remaining calipers in the same manner. Follow the sequence outlined in your vehicle's manual to ensure an efficient and thorough bleeding process. Remember to top up the brake fluid as needed.
Torquing the Bleed Nipples
Once you have completed the bleeding procedure for all the calipers, it is important to torque the bleed nipples to the recommended specifications. Use a torque wrench to tighten the bleed nipples to 20 Newton meters. Be careful not to overtighten and risk damaging the nipples.
Troubleshooting: Snapped Off Bleed Nipples
In some cases, you may encounter issues with over-tightened bleed nipples, resulting in them snapping off. If this happens, the affected caliper will need to be removed, and the broken bleed nipple replaced. It is crucial to torque the bleed nipples correctly to avoid such problems.
Conclusion
Bleeding the brakes is a critical maintenance task that ensures the optimal performance of your vehicle's braking system. By following the step-by-step process outlined in this article and using the appropriate tools and techniques, you can successfully bleed the brakes on your STI. Regular brake fluid maintenance is essential for safety and should be performed according to your vehicle manufacturer's recommendations.
Highlights:
- Brake bleeding is crucial for maintaining the effectiveness of the braking system.
- Always check the brake fluid level before starting the process.
- Start with the caliper furthest from the master cylinder to ensure proper bleeding.
- Bleed the inner bleed nipple first, followed by the outer nipple.
- Move systematically through all the calipers, following the sequence in the vehicle's manual.
- Torque the bleed nipples to the recommended specifications to avoid damage.
- Over-tightened bleed nipples can break off and require replacement.
FAQ:
Q: Can I use a vacuum bleeder instead of the two-man method?
A: Yes, a vacuum bleeder can be used as an alternative to the two-man method. However, ensure that the vacuum bleeder is compatible with your vehicle's braking system.
Q: How often should I bleed my brakes?
A: Brake bleeding frequency depends on various factors such as driving conditions, vehicle age, and manufacturer recommendations. It is generally recommended to perform a brake fluid flush every 2-3 years or as specified in your vehicle's maintenance schedule.
Q: What happens if air is not entirely removed from the brake system?
A: Air in the brake system can cause a spongy brake pedal feel and reduce braking performance. It is crucial to ensure complete removal of air during the bleeding process to maintain optimal braking efficiency.
Q: Can I use any type of brake fluid for bleeding?
A: It is essential to use brake fluid that is compatible with your vehicle's specifications. Refer to your owner's manual or consult with a professional to determine the appropriate type of brake fluid to use.
Q: Should I bleed the brakes myself or seek professional assistance?
A: Brake bleeding can be performed by a competent DIYer with the necessary tools and knowledge. However, if you are unsure or uncomfortable with the process, it is recommended to seek professional assistance to ensure proper brake system maintenance.
Q: How do I know if my brake fluid needs to be changed?
A: Brake fluid should be changed according to the manufacturer's recommendations or if it appears dirty or contaminated. Additionally, if you notice a decrease in braking performance or a spongy brake pedal, it may indicate the need for a brake fluid change.
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