Water pump seal A703
The A703 seal is a shaft seal for hydraulic piston or gear pumps. It is specifically sized for the sealing housings of pumps with the A703 code — precise fit, without the risk of leaks caused by incorrect tolerances. A worn pump seal directly results in flow losses, unstable pressure, and oil stains in the shaft area — symptoms that worsen quickly if you do not intervene. The complete code, exact dimensions, and available materials are listed at hydsealstore.ro, along with compatibility with the main pump brands.
The Role and Importance of the A703 Pump Seal in Hydraulic Systems
The A703 seal seals the pump shaft outlet area through dynamic contact between the sealing lip and the surface of the rotating shaft. The internal stainless steel spring maintains constant contact force even after the lip wears, while the metal housing ensures rigid fixation in the housing. Loss of sealing causes visible external leaks, reduced flow and, over time, contamination of the bearings with degraded oil or water entering the circuit. Made of NBR or FKM — up to +120°C and +200°C respectively, the choice is made according to the fluid and temperature. The other sealing components of the pump are covered by hydraulic seals, including O-rings and static seals for the pump covers.
Sealing Characteristics and Resistance to Flow and Pressure
Clear signs that it is time to replace it: visible oil stains in the pump shaft area, lower than normal output flow or pressure, unusual noises from the pump area, or increased oil consumption. At the first sign, immediate intervention prevents damage to the bearings and gears — much more expensive components, and in the case of piston pumps, contamination of the circuit with fine metal particles that destroy the entire system. The cost of the seal is a fraction of the cost of a new pump. The complete system also includes hydraulic wipers on the supplied cylinders, which indirectly protect the A703 seal by keeping the fluid clean.
Replacement Criteria and Correct Installation for the A703 Pump
Confirm that your pump is compatible with the A703 code — check the pump nameplate and the exact dimensions with a caliper, not just from memory of the last overhaul. Choose the material according to the fluid in the system: NBR for standard mineral oils, FKM for synthetic or biodegradable fluids or temperatures above +120°C. The shaft must be clean and visually inspected — a scratched surface quickly wears the new seal and shortens its service life to a few weeks. It should be lightly lubricated and inserted with a mandrel without sharp edges, with the spring facing the inside of the pump. Seals for rotating shafts with other dimensions are available in the range of seals.
Advantages of Purchasing the A703 Pump Seal from Hydraulic Seals Store
For replacing the shaft seal of a hydraulic pump, Hydraulic Seals Store offers A703 seals in versions suitable for the corresponding applications. Before ordering, it is important to check the pump code and the actual dimensions of the seal or housing. A small difference in size can lead to improper sealing and the occurrence of leaks.
Depending on the fluid and operating temperature, it may be necessary to choose between NBR and FKM. If you have doubts regarding the compatibility or identification of the A703 seal, you can send us the pump code and the available dimensions. Our team can help you verify the appropriate version before ordering.