TC-451-26-003 – Brake Hose Inspection and Replacement

Severity Level

🔴 RED – Immediate Action Required

High severity

DO NOT DRIVE THE CAR.

Click on this link to leave your phone number and VIN so that we can arrange a workshop appointment for you

A potential defect may affect the vehicle's braking performance. The vehicle must not be driven until it has been inspected and, if necessary, repaired by an authorized service partner.

A call center agent will contact you to arrange a short-term workshop appointment.

Do not drive the vehicle to the workshop yourself. The call center or service partner will coordinate the appropriate transport or recovery of the vehicle.

Campaign ID: TC-451-26-003
Vehicle: smart fortwo
Model series: 451
Model years: 2007–2014
Campaign type: Technical Safety Campaign
Severity: Red – High
Status: Active
Estimated repair time: 0.8–1.5 hours

Campaign Overview

A technical safety campaign has been introduced for selected smart fortwo vehicles of model series 451.

On affected vehicles, one or more flexible brake hoses may develop premature deterioration due to a combination of material aging and mechanical stress.

In rare cases, the affected brake hose may develop a leak. A loss of brake fluid can result in reduced braking performance and an increased brake pedal travel.

Because braking performance may be affected, vehicles included in this campaign must not be driven until they have been inspected by an authorized workshop.

Customer Complaint / Possible Symptoms

Possible indications may include:

• Brake warning lamp illuminated
• Brake fluid warning message
• Increased brake pedal travel
• Brake pedal feels unusually soft
• Reduced braking performance
• Visible brake fluid underneath the vehicle
• Low brake fluid level
• No noticeable symptoms prior to inspection

The absence of symptoms does not mean that an affected vehicle is safe to continue driving.

Vehicles Affected

This campaign applies to selected:

smart fortwo Coupé (451)
smart fortwo Cabrio (451)

Production period: 2007–2014

Campaign applicability must always be confirmed using the Vehicle Identification Number (VIN).

Not every smart fortwo of model series 451 is affected.

Cause

Due to material aging and mechanical stress, the flexible brake hoses installed on certain vehicles may deteriorate earlier than intended.

Over time, cracks may develop in the hose material. In an advanced condition, this may result in brake fluid leakage.

A loss of brake fluid may reduce the hydraulic pressure available to the braking system and therefore affect braking performance.

Customer Action

DO NOT DRIVE THE VEHICLE.

No attempt should be made to drive the vehicle to a workshop, even if no warning lamp or other symptom is currently present.

A call center agent will contact the customer to:

1. Confirm the vehicle and contact details.
2. Identify an appropriate authorized service partner.
3. Arrange a short-term workshop appointment.
4. Coordinate vehicle recovery or transportation where required.
5. Provide information about the next steps.

If a brake warning lamp is already illuminated or brake fluid is visible underneath the vehicle, the vehicle must remain stationary.

Call Center Guidance

For vehicles with an open RED campaign, the call center agent should clearly inform the customer that the vehicle must not be driven.

The agent should:

• Confirm the VIN and campaign status.
• Confirm the current location of the vehicle.
• Ask whether any brake warning messages or symptoms have occurred.
• Arrange the earliest available workshop appointment.
• Coordinate vehicle recovery or transportation according to the applicable market process.
• Record the customer contact and appointment details in the campaign system.

The customer should not be instructed to drive the vehicle to the service partner.

Workshop Procedure

1. Verify Vehicle Eligibility

Check the VIN in the campaign or warranty system.

Proceed only if campaign TC-451-26-003 is shown as open for the vehicle.

2. Secure and Prepare the Vehicle

Ensure that the vehicle is safely positioned in the workshop.

Do not perform a road test before the brake system has been inspected.

Check the brake fluid level before beginning the inspection.

3. Inspect Brake Hoses

Raise the vehicle according to the approved workshop procedure.

Inspect all affected flexible brake hoses for:

• Surface cracks
• Material deterioration
• Abrasion
• Bulging or deformation
• Leakage
• Damage around connection points
• Incorrect routing or contact with adjacent components

4. Evaluate the Condition

No visible damage or leakage

If no damage is identified:

1. Replace the affected brake hoses according to the campaign instructions.
2. Refill or correct the brake fluid level as required.
3. Bleed the braking system according to the workshop procedure.
4. Check the system for leaks.
5. Perform a brake function test.

Damage or deterioration detected

If cracking, abrasion, deformation, or other deterioration is identified:

1. Replace all components specified by the campaign instructions.
2. Inspect adjacent brake components.
3. Check the brake fluid level.
4. Refill with approved brake fluid as required.
5. Bleed the braking system.
6. Perform a pressure and leak test.
7. Perform a brake function test.

Brake fluid leakage detected

If active brake fluid leakage is identified:

1. Do not move or road-test the vehicle until repairs have been completed.
2. Replace the affected brake hose and any additional damaged components.
3. Inspect the complete affected brake circuit.
4. Refill the braking system with approved brake fluid.
5. Bleed the braking system.
6. Perform a pressure and leak test.
7. Verify correct brake pedal pressure.
8. Perform the prescribed final brake system test.

Required Parts

Always verify the latest part numbers and specifications in the electronic parts catalog before ordering.

Required Tools

Depending on the repair required, the following equipment may be necessary:

• Vehicle lift
• Brake bleeding equipment
• Brake fluid pressure testing equipment
• Diagnostic tester
• Inspection lamp
• Standard brake system workshop tools

Final Safety Check

Before the vehicle is released to the customer:

1. Confirm that all specified brake hoses have been replaced.
2. Verify the correct brake fluid level.
3. Confirm that the braking system has been correctly bled.
4. Check the complete repaired area for leakage.
5. Verify correct brake pedal pressure and travel.
6. Check for brake-related warning messages.
7. Perform the prescribed brake function test.
8. Confirm that the campaign has been recorded as completed.

The vehicle may only be released once all required safety checks have been successfully completed.

Completion Criteria

The technical campaign can be marked as completed when:

• Vehicle eligibility has been confirmed using the VIN.
• All affected brake hoses have been inspected and replaced as specified.
• Any additional damage has been repaired.
• The brake fluid level and hydraulic system have been checked.
• The braking system has passed the prescribed functional and safety checks.
• Completion has been documented in the campaign system.

Warranty / Campaign Claim

Submit the completed work under campaign TC-451-26-003 using the applicable campaign operation code.

Additional components required as a direct result of the identified defect should be documented according to the applicable warranty process.

Important Notes

This technical campaign has a RED severity level.

The vehicle must not be driven until the campaign has been completed.

A call center agent will proactively contact the customer to arrange a short-term workshop appointment and coordinate the required next steps.

The campaign is VIN-specific. Not every smart fortwo of model series 451 is affected.