CAT 320C 320D 200-3269 244-8483 SBS120 Hydraulic Pump Repair Kit Rotary Group Compatible with Cat-erpillar

1. Product Overview & Wholesale Price Range

The Cat-erpillar CAT 320C / 320D SBS120 Hydraulic Main Pump Repair Kit (OEM Part # 200-3269 / 244-8483 / 259-0815 / SBS120) includes the complete internal rotary group: cylinder block, piston shoes with bronze slippers, distributor valve plate (RH/LH), retainer plate, ball guide, swash plate, and drive shaft built for 20-ton heavy excavators undergoing main pump overhauls.

• Factory Wholesale Price: $380 – $850 USD (Direct manufacturer pricing — Save up to 50% vs regional dealer markups)
• Included Spare Parts: Cylinder Block (1pc) + Piston Shoes (9pcs) + Valve Plate (1pc) + Retainer Plate (1pc) + Ball Guide (1pc) + Swash Plate (1pc) + Drive Shaft (1pc)
• MOQ & Bulk Discount: 1 Set (Tiered wholesale discounts available for hydraulic repair shop batch orders)
• Lead Time: 1–3 business days (Large factory stock ready for immediate worldwide dispatch)
• Warranty: 12 Months full replacement warranty with high-lead bimetallic bronze durability guarantee

2. Application Worksite Checklist (施工场景清单)

Engineered to restore original hydraulic working pressure across demanding 20-ton excavator jobsites:

• Heavy Open-Pit Quarrying & Mining: Restores maximum digging force and flow output under continuous 350 Bar peak pressure on CAT 320D excavators.
• Deep Foundation Excavation & Earthmoving: High thermal resistance bimetallic plates prevent power loss during continuous long-hour digging cycles.
• Highway Infrastructure & Heavy Trenching: Precision lapped cylinder faces ensure zero internal oil bypass during fast bucket loading cycles.
• Building Demolition & Heavy Breaker Operations: Case-hardened steel pistons withstand continuous high hydraulic pressure shockwaves from hammer attachments.

3. Hydraulic Pump Overhaul & Fault Diagnostic Guide (维修包常见故障排查)

If your CAT 320C / 320D excavator main pump is exhibiting performance degradation, check the wear symptoms below:

• Fault 1: Thermal Pressure Loss & Machine Slowdown After 1 Hour (热车掉压发慢/内泄)
  Root Cause: Wear gap between the cylinder block face and valve plate surface causing internal high-pressure thermal oil bypass.
  Solution: Replace the worn rotary group with our precision lapped SBS120 cylinder block and valve plate kit (OEM 200-3269).
• Fault 2: Engine Stalls or Lacks Digging Force Under Heavy Bucket Load (憋车熄火/无力)
  Root Cause: Scoring on piston shoe brass slippers or stickiness in the swashplate cradle pivot.
  Solution: Install new SBS120 copper-coated piston shoes and swashplate group to restore smooth stroke control.
• Fault 3: Black Copper Filings Found in Hydraulic Tank Oil Filter (油箱内有黑粉铜屑)
  Root Cause: Friction galling and thermal melting of the bronze layer on the piston slippers.
  Solution: Flush the entire hydraulic oil system, clean main control valve, and rebuild pump with a new SBS120 repair kit.
• Fault 4: Abnormal Pulsation Noise & Chattering From Pump Housing (泵体异响/震动)
  Root Cause: Broken retainer plate spring, worn ball guide, or pitted swashplate surface.
  Solution: Replace ball guide, retainer plate, and swashplate assembly to eliminate mechanical chatter.

4. Hot Machinery Replacement Parts Recommendation (5大品类热门推荐表)

Explore our factory-direct replacement hydraulic components compatible with major global excavator brands:

5. Frequently Asked Questions & Technical Support (QA 问答专区)

Q1: How do I verify if this SBS120 repair kit fits my CAT 320C or 320D excavator main pump?
A: Check your original pump nameplate for OEM part numbers 200-3269, 244-8483, or SBS120 stamp. You can also send us photos of your old cylinder block and pistons for instant verification.

Q2: What is the material composition of the SBS120 cylinder block and piston slippers?
A: Our SBS120 cylinder blocks are made of high-density alloy steel with bimetallic copper-alloy distribution faces, and the piston shoes feature high-lead bronze slippers rated for continuous 350 Bar pressure.

Q3: Is this SBS120 repair kit a complete drop-in overhaul solution?
A: Yes, the kit includes all major internal wear components (cylinder, 9 pistons, valve plate, retainer plate, ball guide, swashplate, and drive shaft) required for a complete pump rebuild.