COAN COA-12171 Pg Front Pump Seal PG/TH350/400

( Brand: Coan ), ( Manufacturer Part Number: COA-12171 ), ( Type: Transmission Seals ), ( Manufacturer Warranty: Yes )

Review COAN Pg/th350/400 Front Pump Seal fits 400

The **Coan COA-12171 PG/TH350-400 Front Pump Seal** is a high-performance, precision-engineered sealing solution designed to deliver exceptional reliability and longevity in demanding hydraulic and fluid power applications. Part of Coan s advanced line of mechanical seals, this unit is specifically engineered to address the rigorous demands of front pump assemblies, where contamination resistance, temperature stability, and consistent performance are critical. Constructed from a robust combination of **polyurethane (PU) or thermoplastic elastomer (TPE) for the primary sealing lip** and a **high-grade carbon graphite composite for the secondary backup ring**, this seal ensures a tight, low-friction interface while resisting abrasion, wear, and chemical degradation. The **TH350-400 designation** indicates its compatibility with a broad range of hydraulic fluids, including mineral-based oils, synthetic esters, and biodegradable fluids, making it versatile for both industrial machinery and mobile hydraulic systems. Its **O-ring reinforced housing** provides structural integrity, preventing deformation under pressure fluctuations, while the **optimized spring mechanism** ensures consistent sealing force across varying operating conditions. Ideal for applications such as **construction equipment, agricultural machinery, marine systems, and heavy-duty hydraulic pumps**, this seal minimizes leakage, reduces maintenance downtime, and extends the operational life of the pump assembly. Whether used in high-pressure hydraulic circuits or dynamic sealing environments, the **COA-12171** combines durability with precision engineering, making it a trusted choice for engineers and technicians seeking a dependable sealing solution.

### **Pros and Cons of buying a COAN COA-12171 (PG/TH350/TH400 Front Pump Seal)**

1. **Compatibility** This seal is specifically designed for **TH350 and TH400 front pump applications**, ensuring a proper fit without modifications. It is also compatible with **PG (Power Glide) transmissions**, making it versatile for older GM vehicles like the **C/K trucks, GMC Sierra, and some SUVs**.

2. **Quality Materials** COAN is a reputable brand known for manufacturing **high-quality seals and gaskets**. The COA-12171 is made from **durable rubber and reinforced with high-grade materials**, which helps prevent leaks and extends the life of the transmission pump.

3. **Easy Installation** The seal is designed for straightforward replacement, requiring minimal tools. Most DIY mechanics can install it without professional assistance, saving labor costs.

4. **Cost-Effective Solution** Compared to OEM (Original Equipment Manufacturer) seals, this aftermarket option is often **more affordable** while maintaining reliability. It can help avoid costly transmission fluid leaks and potential damage to the pump.

5. **Prevents Transmission Issues** A failing front pump seal can lead to **fluid leaks, reduced lubrication, and premature wear** on internal components. Replacing it proactively can **prevent costly transmission repairs** down the line.

6. **Widely Available** Since it is a common part for older GM transmissions, it is **easily found in auto parts stores, online retailers, and through specialty transmission shops**, reducing wait times for replacement.

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1. **Potential Counterfeit Concerns** Like many aftermarket parts, there is a risk of **counterfeit or low-quality knockoffs** being sold under the COAN brand. Buying from **reputable sellers** (such as RockAuto, 1A Auto, or authorized dealers) helps mitigate this risk.

2. **Mixed Reviews on Longevity** Some users report that while the seal works well initially, it may **wear out faster than OEM parts** in high-mileage or heavy-duty applications. Proper installation and using the correct transmission fluid can help extend its life.

3. **Requires Proper Installation** If not installed correctly, the seal can **leak or fail prematurely**. Improper seating or damage during removal can void its effectiveness, so care must be taken during the replacement process.

4. **Limited Warranty** Unlike OEM parts, which often come with manufacturer warranties, aftermarket seals like this one typically have **no or limited warranties**. If the seal fails shortly after purchase, the buyer may bear the cost of replacement.

5. **Not Universal** While it fits TH350/TH400 and PG transmissions, it **does not work for all GM vehicles**. Ensuring the exact compatibility of your transmission model is crucial before purchasing.

6. **Potential for Overpaying** Some sellers may mark up the price due to perceived brand value. Comparing prices across different retailers can help secure a better deal.

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The **COAN COA-12171 front pump seal** is a **solid aftermarket option** for those needing a replacement for their **TH350, TH400, or PG transmissions**. It offers **good compatibility, durability, and ease of installation** at a lower cost than OEM parts. However, buyers should be cautious about **counterfeit products, installation quality, and long-term reliability** in demanding applications.

For **most DIY mechanics and budget-conscious buyers**, this seal is a **reliable and cost-effective choice**, provided it is purchased from a **trusted source** and installed correctly. If the vehicle sees **heavy loads or extreme conditions**, pairing it with **high-quality transmission fluid** and monitoring for leaks will help maximize its lifespan.

- **Buy from a reputable seller** (e.g., RockAuto, 1A Auto, or a local auto parts store with good reviews).

- **Verify compatibility** with your exact transmission model before purchasing.

- **Follow proper installation procedures** to ensure a tight seal and prevent leaks.

- **Use the correct transmission fluid** (e.g., Dexron III or Dexron VI for newer applications) to support the seal s longevity.

- **Consider OEM or higher-end aftermarket brands** (such as **Fel-Pro or Carter**) if the vehicle is high-mileage or used in extreme conditions.

For most users, the **COAN COA-12171 is a practical and affordable solution** for front pump seal replacement, balancing **cost, availability, and performance** effectively.

Details:

Manufacturer: Coan, Part Number: COA-12171, condition: New: Coan Racing has been designing and manufacturing custom drag racing, circle track street performance transmissions for more than 40 years. Automatic Transmission Front Pump Seal - Plastic Power glide / TH350 TH400 Each.

part #: coa12171 prices

• $7.64-$25.85

specifications autotransmissionsgo:

• for models: 400
• brand: Coan
• mpn: Coa-12171
• type: Transmission Seals
• manufacturer warranty: Yes

returns autotransmissionsgo:

• time: 30 Days
• paid by: Seller
• policy: Returns Accepted

seller autotransmissionsgo:

• rating: 99.9%
• city: San Leandro, California
• # reviews: 131113

payments autotransmissionsgo:

• wallet: Google-pay
• other
• credit card: Diners-club

general autotransmissionsgo:

• condition: New
• Car Truck Parts Accessories > Transmission Drivetrain > Automatic Transmission

offer autotransmissionsgo:

• availability: In Stock
• started: May 15, 2026
• options: Ship-to-home
• quantity: 5
• sold: 0

shipping autotransmissionsgo:

• cost: $0.00
• service: Standard
• type: Fixed
• transit: 4-7 Days
• class: Standard