Description
Vacuum reservoir for Citroën and Peugeot with 1.4 HDi, 2.0 HDi and 2.2 HDi engines.
This vacuum reservoir, commonly referenced under part numbers 9635576177 and 162779, is a direct-fit replacement designed for Stellantis diesel applications. It restores reliable vacuum supply for the brake servo and related vacuum-operated actuators, helping to recover correct brake assist and pedal feel. The part is suitable for professional workshops as well as experienced DIYers looking for a straightforward swap using standard tools. Including the correct reservoir in repairs reduces the risk of fluctuating brake assistance and intermittent faults related to insufficient vacuum.
Technical Information
- Manufacturer: Stellantis (Citroën / Peugeot)
- Model: Citroën C3; Citroën C5; Citroën C5 X7; Peugeot 1007; Peugeot 307; Peugeot 607 — For 1.4 HDi, 2.0 HDi and 2.2 HDi engines
- Product Codes: 9635576177
- Additional Numbers: 162779
Installation Recommendations
- Park the vehicle on a level surface, switch off the engine and allow it to cool. Work with the ignition off when disconnecting vacuum lines.
- Locate the reservoir in the engine bay (typically near the brake servo or firewall). Note hose routing and the orientation of the check valve before removal.
- Disconnect vacuum hoses and electrical connectors (if present). Remove mounting bolts or clips and fit the replacement in the original position.
- Ensure the check valve is fitted with correct flow direction (arrow toward the vacuum source). Replace any brittle hoses or clamps with new ones to ensure an airtight connection.
- After installation, verify the system with a handheld vacuum pump or gauge: the reservoir should hold vacuum and the brake pedal should return to normal assist behavior. Re-check for audible leaks (hissing) and secure all fastenings.
Most Common Failure Causes
- Plastic fatigue and cracking from long-term heat exposure and vibration, causing vacuum leaks.
- Failure of the check valve or internal seals, which prevents the reservoir from holding vacuum.
- Degraded or split vacuum hoses and loose clamps allowing air ingress.
- Related vacuum pump malfunction: if the vacuum pump is weak or fails, the reservoir will not refill properly and symptoms may appear even if the reservoir is intact.
Symptoms And When To Replace
- Hard or heavy brake pedal, especially after engine start, indicating reduced brake assist.
- Intermittent loss of brake assistance or a change in pedal travel when accelerating or under load.
- Audible hissing from the engine bay or visible cracks/damage to the reservoir body or hose connections.
- Recommended to inspect the reservoir and hoses during routine service intervals (for example around 100,000 km) or immediately if vacuum-related symptoms appear.
Choose this vacuum reservoir when you need a reliable replacement that matches original fitment for many Citroën and Peugeot HDi engines. Use the part numbers 9635576177 and 162779 when searching to ensure correct compatibility and fast identification in parts catalogs.
