Hydro Gear Lip Seal – Fits BDA, BDP-10A, PE, PG, PJ, PK Series Pumps (Replaces 51161, 50735)

Product Details

This Hydro Gear Lip Seal is a direct-fit replacement for BDA, BDP-10A, PE, PG, PJ, and PK Series Pumps used in residential and commercial lawn equipment. Measuring 17 × 40 × 7 mm, this seal ensures proper containment and extends the service life of your hydrostatic transmission across Hydro-Gear, MTD, Cub Cadet, MTD Pro, Troy Bilt, Bolens, Craftsman, and White Outdoors machines.

This aftermarket seal directly replaces Hydro Gear part numbers 51161 and 50735, offering a reliable and cost-effective solution for routine maintenance or transmission repair.

• Precision-molded construction for consistent fitment across multiple pump series
• Designed for use in residential and commercial hydrostatic transmission systems
• Includes one seal ready for installation

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Technical Specs

Seal Dimensions

17 × 40 × 7 mm

Application

Hydrostatic transmission pumps

Compatible Pump Series

BDA, BDP-10A, PE, PG, PJ, PK

Material

Durable elastomer compound

Warranty

1 year

What's in the Box

• 1 × Lip Seal

Installation Notes

1. Drain all hydraulic fluid from the pump housing and relieve system pressure before beginning work.
2. Remove the pump assembly from the unit according to your equipment's service manual.
3. Carefully extract the old seal using a seal puller or flat blade, taking care not to damage the shaft or housing bore.
4. Clean the seal bore and shaft thoroughly with a lint-free cloth and solvent to remove debris, oil residue, and corrosion.
5. Inspect the shaft surface for scoring, pitting, or wear that could compromise the new seal.
6. Apply a thin coat of clean hydraulic oil to the new seal lip and outer diameter.
7. Position the seal with the lip facing inward (toward the fluid side) and press it evenly into the bore using a seal driver or appropriate socket.
8. Ensure the seal is fully seated and flush with the housing surface.
9. Reassemble the pump, refill with manufacturer-recommended hydraulic fluid, and bleed air from the system per your service manual.
10. Test operation at low speed and check for leaks before returning to full service.

Troubleshooting & FAQ

How do I know if my lip seal needs replacement?

Common signs include hydraulic fluid leaking from the pump shaft area, loss of hydrostatic drive power, and visible oil residue around the seal housing. If you notice reduced responsiveness or intermittent drive engagement, inspect the seal for wear or damage.

Can I reuse the old seal if it looks intact?

No. Lip seals are single-use components. Even if the seal appears undamaged, removal distorts the sealing lip and compromises its ability to maintain hydraulic pressure. Always install a new seal during pump service.

What happens if the seal is installed backward?

Installing the seal with the lip facing outward will cause immediate hydraulic fluid leakage and loss of pump function. Always confirm the lip faces the fluid side before pressing the seal into place.

Do I need to apply sealant or adhesive?

No. A properly sized lip seal requires only a light coat of clean hydraulic oil on the sealing lip and outer diameter. Sealants or adhesives can interfere with seal flexibility and may cause installation damage.

Will this seal fit all Hydro-Gear pumps?

This seal is sized for BDA, BDP-10A, PE, PG, PJ, and PK series pumps. Other Hydro-Gear models may use different seal dimensions. Always cross-reference your pump model and original part number before ordering.

How often should I replace the lip seal?

Replace the seal whenever the pump is disassembled for service, or immediately if you observe fluid leakage. In high-hour commercial applications, inspect the seal annually as part of routine transmission maintenance.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

• Verify images/specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safety and performance.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
• Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
• Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.