Citroen C1 Brake Disc Replacement Guide

Your Citroen C1, a popular choice for nipping around town, relies heavily on its braking system for safety and performance. Over time, like all vehicles, the brake discs can wear down, leading to reduced stopping power and potential safety concerns. This guide will walk you through the process of replacing the brake discs on your Citroen C1, specifically focusing on the PM PN models. It's crucial to remember that when replacing brake discs, it's always advisable to replace the brake pads simultaneously. This ensures consistent and even braking performance. The procedure is identical for both front and rear discs on the same axle. Safety first! Ensure the engine is switched off and the vehicle is parked on a level surface. Engaging the handbrake and placing chocks behind the wheels will provide an extra layer of security.

Essential Tools and Materials

Before you begin, gather all the necessary tools and materials to make the job as smooth as possible. Having everything to hand will prevent unnecessary trips to the tool shop.

• New brake discs (for the relevant axle)
• New brake pads (for the relevant axle)
• Jack and axle stands
• Wheel brace
• Socket set and wrenches (metric sizes, typically 13mm, 17mm, 19mm)
• Torque wrench
• Wire brush
• Brake cleaner
• Penetrating oil (like WD-40)
• C-clamp or brake caliper spreader tool
• Gloves and safety glasses
• Torque wrench
• Gloves and safety glasses
• A suitable container for old brake fluid (if bleeding the brakes is necessary)

Step-by-Step Guide to Replacing Brake Discs

This guide assumes you are working on one wheel at a time. It is recommended to replace brake discs in pairs on the same axle for balanced braking.

1. Prepare the Vehicle

Park your Citroen C1 on a flat, stable surface. Engage the handbrake firmly. Loosen the wheel nuts on the wheel you will be working on, but do not remove them completely yet. Place wheel chocks behind the wheels on the opposite axle for added safety.

2. Jacking Up the Vehicle and Removing the Wheel

Locate the correct jacking point for your C1 (refer to your owner's manual). Safely raise the vehicle using the jack and support it securely with an axle stand. Once the vehicle is stable, remove the wheel nuts completely and take off the wheel. You should now have access to the brake assembly.

3. Accessing the Brake Caliper

The brake caliper is the component that presses the brake pads against the disc. To remove the caliper, you'll typically need to undo two bolts on the rear of the caliper. These are often referred to as caliper carrier bolts. Use the appropriate socket or wrench to loosen and remove these bolts. You may need to use penetrating oil if they are seized. Once the bolts are removed, you should be able to pivot the caliper upwards or slide it off the brake disc. If it's stiff, you might need to gently lever it. Do not let the caliper hang by the brake hose. Support it with a piece of wire or bungee cord to avoid damaging the hydraulic line.

4. Removing the Old Brake Pads

With the caliper out of the way, you can now remove the old brake pads. They are usually held in place by retaining clips or pins. Carefully remove these clips or pins, and then slide out the old brake pads. Note the orientation of the pads, as the new ones will need to be fitted in the same way.

5. Compressing the Caliper Piston

Before you can fit the new, thicker brake pads and disc, you'll need to push the caliper piston back into its housing. This is done to create enough space. Use a C-clamp or a dedicated brake caliper spreader tool. Place the clamp or spreader against the piston and the back of the caliper body, and slowly tighten it to push the piston back. Keep an eye on the brake fluid reservoir under the bonnet; as you push the piston back, the fluid level will rise. If it looks like it might overflow, you may need to remove a small amount of fluid using a syringe. Be careful not to damage the rubber dust seal around the piston.

6. Removing the Old Brake Disc

The brake disc is usually held onto the hub by one or two small grub screws or Torx screws. These can sometimes be very tight or even rusted in place. Apply penetrating oil and allow it to soak in. You may need to tap the end of the screwdriver or Torx bit with a hammer to help break the rust seal. Once the screws are removed, the old brake disc should be able to be pulled off the hub. If it's still stuck, you might need to use a rubber mallet to gently tap it off, or in stubborn cases, a hub puller. Ensure the hub mating surface is clean.

7. Cleaning and Preparing the Hub

Before fitting the new disc, it's crucial to clean the hub mating surface thoroughly. Use a wire brush to remove any rust, dirt, or old gasket material. A clean, flat surface is essential for the new disc to sit correctly and ensure even braking. Spray the cleaned surface with brake cleaner to remove any grease or debris.

8. Fitting the New Brake Disc

Slide the new brake disc onto the hub. Ensure it sits flush and is correctly aligned. Secure it with the new grub screws or Torx screws provided with the new disc, or re-use the old ones if they are in good condition. Tighten these screws firmly, but do not overtighten as they are quite small.

9. Fitting the New Brake Pads

With the new disc in place, you can now fit the new brake pads. Ensure they are inserted correctly into the caliper bracket, paying attention to any wear indicators. Lubricate the pad mounting points with a small amount of brake grease to prevent sticking and squealing, but avoid getting grease on the pad friction material or the disc surface.

10. Re-fitting the Brake Caliper

Carefully lower the brake caliper back over the new pads and disc. Re-insert and tighten the caliper carrier bolts. These bolts need to be torqued to the manufacturer's specifications. Consult your C1's service manual for the exact torque values. Overtightening or undertightening these bolts can be dangerous.

11. Refitting the Wheel and Lowering the Vehicle

Place the wheel back onto the hub and loosely hand-tighten the wheel nuts. Carefully lower the vehicle off the axle stand using the jack. Once the wheel is on the ground, tighten the wheel nuts in a star pattern to ensure even pressure. Torque the wheel nuts to the manufacturer's recommended specification.

12. Repeat for the Other Side

Repeat the entire process for the other side of the same axle. Remember, it's essential to replace brake discs and pads in pairs for balanced braking.

13. Bedding-In the New Brakes

After replacing the discs and pads, it's important to "bed them in" to ensure optimal performance and longevity. This involves a series of gentle stops from moderate speeds. Avoid heavy braking for the first 100-200 miles. Gradually increase the braking intensity. This process allows the pads and discs to mate correctly and prevents glazing or premature wear.

Common Issues and Troubleshooting

Even with careful work, you might encounter a few snags:

• Stuck Bolts: Use penetrating oil and gentle tapping. If severely rusted, you might need a breaker bar or, in extreme cases, professional help.
• Stuck Discs: A rubber mallet or hub puller is usually effective. Ensure the hub surface is clean.
• Brake Pedal Feels Spongy: This could indicate air in the brake lines. You may need to bleed the brakes.
• Squealing Brakes: This can sometimes happen with new pads or discs. Ensure correct lubrication of contact points and that pads are seated correctly. Sometimes, a few miles of driving will resolve it.

Frequently Asked Questions

Q1: Do I really need to replace the brake pads when changing the discs on my Citroen C1?

A1: Yes, it is highly recommended. New discs have a perfectly flat surface, and old pads will have conformed to the wear pattern of the old discs. Fitting old pads to new discs can lead to uneven braking, reduced performance, and premature wear on both components.

Q2: How often should I check my brake discs?

A2: It's good practice to check your brake discs whenever you have your wheels off for any reason, such as tyre rotation. A visual inspection for scoring, cracking, or a significant lip on the outer edge is advisable. Your mechanic will also check them during regular servicing.

Q3: Can I just replace one brake disc?

A3: No, you should always replace brake discs in pairs on the same axle. This ensures that the braking force is applied evenly to both sides of the car, maintaining stability and control during braking.

Q4: What are the torque settings for the caliper bolts and wheel nuts on a Citroen C1?

A4: Torque settings vary slightly between models and years. Always consult your Citroen C1's owner's manual or a reliable service manual for the precise torque specifications for your vehicle. Typically, caliper bracket bolts are around 30-40 Nm, and wheel nuts are around 90-110 Nm.

Q5: How do I know if my brake discs need replacing?

A5: Signs include a spongy brake pedal, longer stopping distances, grinding noises when braking, visible scoring or cracks on the disc surface, or a pronounced lip around the outer edge of the disc.

Conclusion

Replacing the brake discs on your Citroen C1 PM PN is a manageable task for the home mechanic with the right tools and a methodical approach. Prioritising safety throughout the process is paramount. By following these steps carefully, you can restore your C1's braking system to optimal condition, ensuring your safety and the safety of others on the road. Remember to always refer to your vehicle's specific service manual for precise details and torque settings. Happy motoring!