Help keep coolant sealed inside the system at the thermostat and coolant outlet with the FEL-PRO Multi-Purpose O-Ring 35555, listed as both an engine coolant outlet O-ring and an engine coolant thermostat seal. It fits many vehicles, among them the 2003-2009 Toyota 4Runner, 2000-2009 Toyota Tundra and 2002-2005 Hyundai Sonata, as a direct-fit replacement for the listed applications. See the "Vehicles it fits" section for the full list and engine details.
Fel-Pro designs its gaskets and seals for the repair environment. They are made with proprietary materials to give a reliable seal even on troublesome applications and imperfect sealing surfaces.
- OE specifications: Built to meet or surpass all original equipment specifications.
- Application-specific design: Designed specifically for the listed applications for an accurate fit.
- Made for real-world repairs: Engineered and manufactured with the repair environment in mind.
- Exacting standards: Every Fel-Pro gasket, however small, is engineered to exacting standards using proprietary design, engineering and manufacturing processes.
Signs this O-ring may need replacing include coolant seepage or crusty residue around the thermostat housing or coolant outlet, a coolant level that keeps dropping, or a sweet coolant smell after driving. Other components can cause the same symptoms, so find the source of the leak before replacing parts. Fitting a fresh seal is also worthwhile whenever the thermostat or outlet is opened for service.
Interchange: MD174233 · MD194988 · 112581 · 2550037200 · 2563039800 · 2563139010 · 2563139801 · C31348 · C31507 · C31700 · 635495 · 8AH115171 · 8AH115171B9U · 740224 · MD174234 · 1634632010 · 1634650010 · 411040200
This part cross-references / interchanges with the following part numbers:
MD174233, MD194988, 112581, 2550037200, 2563039800, 2563139010, 2563139801, C31348, C31507, C31700, 635495, 8AH115171, 8AH115171B9U, 740224, MD174234, 1634632010, 1634650010, 411040200
Frequently Asked Questions
What does the FEL-PRO 35555 O-ring do?
It is a multi-purpose O-ring listed as an engine coolant outlet O-ring and thermostat seal. It helps seal that joint so coolant stays inside the cooling system.
Which vehicles does the FEL-PRO 35555 fit?
It fits many vehicles, including the 2003-2009 Toyota 4Runner, 2000-2009 Toyota Tundra and 2002-2005 Hyundai Sonata. See the "Vehicles it fits" section for the full list.
Does it meet original equipment specifications?
Fel-Pro rates it to meet or surpass all original equipment specifications. It uses an application-specific design for the listed vehicles.
What are signs this O-ring may need replacing?
Signs include coolant seepage or residue at the thermostat housing or outlet, a steadily dropping coolant level, or a sweet coolant smell. Confirm the leak source before replacing parts.
Any tips for installing it?
Clean both sealing surfaces and seat the O-ring evenly without twisting it. Follow your vehicle's service information for torque values and for refilling and bleeding the coolant.
