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Porsche > 992 (911) MK1 2019-2024 > 992.1 Carrera 4 Cabriolet 3.0L 2019-24 > Brakes > Caliper and Brake Lines >

Vacuum Line. Porsche 987 Boxster / Cayman 2005-08
Vacuum Line. Porsche 987 Boxster / Cayman 2005-08 - 98735557503
Vacuum Line. Porsche 987 Boxster / Cayman 2005-08 - 98735557503, 98735557501, 98735557502
3
Special Order item
98735557503
Product Information
Product Information
Vacuum Line.
Ensure optimum braking assist performance on your Porsche with this genuine OEM vacuum line. Designed for 987-series vehicles (Boxster/Cayman 2005-08), this line connects the vacuum source to the brake assist or under-body vacuum system, ensuring proper vacuum supply, consistent brake pedal feel, and reliable operation.

Fits:
  • Porsche Boxster 987 2.7L 2005 -08/08
  • Porsche Boxster 987 S 3.2/3.4L 2005-08/08
  • Porsche Cayman 2.7L 987C 2006-08
  • Porsche Cayman S 3.4L 987C 2005-08

Diagram Ref No 14

What This Product Does:

  • This vacuum line carries engine or brake-servo vacuum (negative pressure) from the vacuum source (e.g., intake manifold or dedicated vacuum pump) to the brake master cylinder/servo or rear axle vacuum assist components.
  • The line ensures that the brake assist system (and possibly other vacuum-dependent systems) receive the correct vacuum pressure so that the driver has proper brake pedal feel, braking power assist, and overall vacuum system integrity.
  • A proper vacuum line prevents loss of assist, ensures consistent braking effort, and avoids vacuum leaks that could affect engine operation or brake performance.

Symptoms Of Wear Or When To Replace:
  • Reduced brake assist: The brake pedal may feel harder than normal, or the braking response may require more effort — indicating the vacuum feed is compromised.
  • Hissing or vacuum leak noise: A damaged or cracked vacuum line may emit a hissing sound under load as vacuum is lost.
  • Visible damage, cracking, brittleness, kinks or splits in the hose/line, especially under the vehicle or near mounting points.
  • Check engine or brake system warning lights: A vacuum leak may trigger fault codes related to braking or vacuum-supply detection.
  • Age-related deterioration: Rubber or plastic vacuum hoses degrade over time (heat, road debris, chemical exposure) and for 987-series vehicles these lines are good candidates for preventive replacement.

Why Replacement Matters:
  • Brake safety & performance: A secure, intact vacuum line is critical to ensuring brake assist works properly — directly impacting stopping distances and driver safety.
  • System reliability: A genuine part ensures the correct hose diameter, material and routing — preventing future leaks, vacuum loss and other associated issues.
  • Prevents further damage: A failed vacuum line may cause compensatory wear on other brake components (master cylinder, servo) or affect engine vacuum systems — replacing proactively prevents secondary damage.
  • OEM fitment: Using the correct Porsche part (#98735557503) keeps the system as engineered and avoids mismatches which could reduce reliability or cause fit/clearance issues.
  • Maintains vehicle value & integrity: For Porsche vehicles, even small parts like vacuum lines matter for overall build quality, service history and operational confidence.



Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

98735557503
98735557503
98735557501
98735557502

The product you are viewing cross references to these numbers
Related products
Caliper brake line, Right, Front. Porsche 991 / 981 Boxster / 981 Cayman - 99135558202, 99135558102
2
Caliper brake line, Right, Front. Porsche 991 / 981 Boxster / 981 Cayman
Special Order item
99135558202
Product Information
Product Information
Caliper brake line, Right, Front.

porsche

Fits:
For cars WITHOUT ceramic brake (PCCB)
Porsche 991.1 C2 / C4 2012-16
Porsche 991.2 C2 / C4 2017-19
Porsche 981 Boxster 2012-16
Porsche 982 (718) Boxster 2017-21
Porsche 981 Cayman 2014-16
Porsche 982 (718) Cayman 2017-21

Click 'Zoom in' for large parts diagram.
Diagram ref no 22

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99135558202
99135558202
99135558102

The product you are viewing cross references to these numbers
Hydra tec lubricant for maintenance work and protection Textar - 81001401, 81001400, 81001500
3
Hydra tec lubricant for maintenance work and protection Textar
Black Friday Sale
81001
Product Information
Product Information

Hydra tec lubricant for maintenance work and protection Textar

Available in 75ml Tube or 5ml Sachet

The Advantages of Hydra Tec:

  • Facilitates the installation of hydraulic brake components
  • Tested compatibility with commercially available braking fluids (DOT3, DOT4, DOT4LV, DOT5.1)
  • Free of mineral oils and compatible with EPDM rubber
  • In addition, running surfaces are protected against corrosion

Hydra Tec is suitable for lubricating:

  • Cylinder running surfaces
  • Pistons
  • Sealing elements

Application:
Apply a thin layer of Hydra Tec on the marked sections.

Note:
Hydra Tec should be applied thinly and evenly. 
Never use mineral oils or greases as substitutes.
Do not apply the product on friction surfaces of brake pads or brake discs.

Find out about Textar product verification here