CAT 121-4299 SPACER

CAT 121-4299 is a flat gasket for Caterpillar engine fuel system/hydraulic pump interfaces. It is primarily compatible with CAT C13/C15/C18 engines, 980K/982M loader hydraulic pump flanges, and D10T bulldozer transmission control module interfaces. It is used for static surface sealing to prevent oil/gas leakage. The core information is as follows:

Core Technical Parameters
Item Details
Part Model: CAT 121-4299 (1214299) flat gasket, a static seal, suitable for flange/cover/housing surface sealing, non-locating gasket

Core Material: Stainless steel core + nitrile rubber (NBR) coating (0.05 mm), or multi-layer steel (MLS) + graphite coating, uniform thickness (±0.02 mm), oil-resistant, temperature-resistant, suitable for engine/hydraulic system operating conditions

Key Dimensions: Outer diameter 85 mm, inner diameter 60 mm, thickness 1.5 mm mm, 4 bolt holes, hole diameter 10 mm, hole pitch circle diameter 72 mm, installation tolerance: flatness ≤0.03 mm, surface roughness Ra≤0.8 μm
Single weight: Approx. 0.08 kg
Compatible models: CAT C13/C15/C18 engines (fuel filter housing / hydraulic pump flange), 980K/982M loaders (transmission control module cover), D10T/D10R bulldozers (final drive housing seal), 336GC excavators (hydraulic pipeline flange)
Operating compatibility: Operating temperature -30℃ to +120℃, compatible pressure ≤1.6 MPa, compatible media: engine oil, hydraulic oil, diesel oil, no leakage at sealing surface pressure ≥2 MPa, fatigue life ≥3000 working hours
Core functions and structural features:
Flat sealing leak prevention: The gasket deforms under bolt preload, filling the microscopic gaps of the sealing surface, preventing oil/ Suitable for gas leakage applications, including static flanges and covers, and other planar sealing conditions.

Material compatibility: The stainless steel core ensures strength and rigidity, while the NBR/graphite coating enhances sealing performance and anti-adhesion, preventing coating peeling during disassembly. Suitable for vibration and temperature fluctuations in engineering machinery.

Precise installation positioning: Four bolt holes precisely match the pitch circle diameter, ensuring no misalignment after installation, uniform stress on the sealing surface, and reducing the risk of localized leakage.

Anti-aging and durability: The coating is oil-resistant and anti-aging, and is not prone to cracking or swelling under long-term contact with machine oil/hydraulic oil, ensuring a long seal life.

Installation and maintenance points:
Installation specifications: Clean the sealing surface and gasket, removing oil, rust, and burrs. The flatness of the sealing surface should be ≤0.03 mm, and the surface roughness Ra ≤1.6 μm.

The gasket should be free from twisting and the coating should be undamaged. During installation, the coated side should face the sealing medium. Pre-tighten the bolts diagonally, with a pre-tightening force of 25–30 N·m, avoiding localized over-tightening that could deform the gasket. After installation, inspect the sealing surface for any oil or air leakage. Reconfirm the sealing effect after starting the equipment.

Maintenance Recommendations: Check every 1500 working hours for: gasket aging, coating peeling, and sealing surface gap > 0.1 mm. Replace any problematic gaskets immediately.

When replacing gaskets, prioritize original equipment manufacturer (OEM) or certified parts to ensure dimensional accuracy and coating quality, avoiding leaks caused by ordinary gaskets.

Simultaneously check for sealing surface deformation; repair or replace as necessary to ensure a good seal.