Hydraulic Oil Cooler for John Deere Garden Tractor

Hydraulic Oil Cooler for John Deere Garden Tractor Fits Models: 318, 420

• CORE SIZE: (2) 7 5/8" x 2 1/2" x 2 1/4"
• PORTS: (2) 3/8" Beaded Tube
• OEM Part Numbers: AM39311

repair

For a small leak in an aluminum hydraulic fluid cooler tubing under pressure, here are cost-effective repair options, ranked by suitability:

Epoxy Repair (Best Option):

• Why: High-strength, two-part epoxy designed for metal (e.g., JB Weld or Devcon) can seal small leaks effectively, withstand pressure, and resist hydraulic fluid. Easy to apply, no special skills needed.
• How: Clean and degrease the area thoroughly. Sand lightly for better adhesion. Apply epoxy over the hole, covering a slightly larger area. Let cure fully (24 hours). Test for leaks.
• Cost: ~$10–$20.
• Durability: Good for small leaks, holds up to moderate pressure and fluid exposure.

Consider the following products:

• J-B Weld Original Cold Weld Epoxy (Part: 8265-S) - Strong, durable, hydraulic fluid-resistant.
• Devcon Aluminum Putty (F) (Part: 10610) - Excellent for aluminum repairs, high pressure resistance.
• J-B Weld WaterWeld Epoxy Putty Stick (Part: 8277) - Easy to apply, chemical-resistant, suitable for small leaks.

For a small leak this is the most recommended procedure. Use a high-quality metal epoxy for the best balance of cost (~$15), ease, and durability. Ensure the area is clean and dry before application. If the repair fails or the hole grows, consider replacing the cooler ($350–$400). Test the repair under operating pressure to confirm it holds.

Volatilizing Self-Adhesive Rubber Tape + Hose Clamps:

• Why: Self-amalgamating rubber tape (e.g., silicone rescue tape) can seal small leaks temporarily and withstands pressure and fluid. Hose clamps add extra security.
• How: Clean and dry the area. Wrap tape tightly over the hole, overlapping layers. Secure with a hose clamp if tubing size allows. Test for leaks.
• Cost: ~$10–$15 for tape, ~$5 for clamps.
• Durability: Temporary fix, may degrade over time due to fluid exposure.

Soldering:

• Why: Possible for aluminum with specialized low-temperature aluminum solder (e.g., Alumiweld) and flux, but challenging due to aluminum’s oxide layer and heat dissipation. Risk of overheating nearby tubing.
• How: Clean and sand the area. Use a propane torch with aluminum solder and flux. Apply carefully to avoid further damage. Test for leaks.
• Cost: ~$15–$30 for materials.
• Durability: Moderate, but success depends on skill and surface prep.

Welding (Least Recommended):

• Why: TIG welding aluminum requires expertise, specialized equipment, and risks damaging thin tubing or creating new leaks due to heat. Not cost-effective for a small repair.
• How: Requires professional welder with TIG setup for aluminum. Clean area, weld the hole, and test.
• Cost: ~$50–$100+ for professional service.
• Durability: High if done correctly, but overkill for a small leak.

external sources

• https://www.superiorcooling.co/am39311-hydraulic-oil-cooler-john-deere-lawn-tractor-318-420.html