126-1937 Boom Cylinder Seal Kit 85mm Rod 120mm Bore for Caterpillar 320B Excavator

126-1937 Boom Cylinder Seal Kit

126-1937 is a hydraulic cylinder seal kit used for boom cylinder repair on Caterpillar 320B series excavators. The applicable boom cylinder configuration uses an 85 mm rod and 120 mm bore and is associated with cylinder group 118-4023.

The kit provides the sealing and backup components required during boom cylinder overhaul. Fitment should be confirmed by the 126-1937 part number, cylinder group and machine configuration rather than by excavator model alone.

Caterpillar 320B Excavator Fitment

Caterpillar lists 126-1937 for 320B series excavators including 320B, 320B L, 320B LU, 320B N, 320B LL, 320B FM LL and 320B U configurations.

The related 118-4023 hydraulic cylinder arrangement is also listed by Caterpillar for the same 320B machine family. When available, confirm both the seal kit number and cylinder group before ordering, especially where the machine has previously had cylinder repairs or component replacements.

What's Included in the 126-1937 Seal Kit

The 118-4023 boom cylinder parts group identifies 126-1937 as the available seal kit and marks the following sealing components as included in the repair kit. These numbers identify components inside the kit and are not cross references for 126-1937.

The table above describes the reference repair-kit positions associated with the 118-4023 boom cylinder group. Packaging, seal manufacturer and individual component appearance can vary by supply batch, so confirm any specific brand requirement before ordering.

85mm Rod and 120mm Bore Rebuild Checks

Before fitting the new seal kit, inspect the 85 mm piston rod for scoring, corrosion and chrome damage. Check the 120 mm cylinder bore, piston, gland and seal grooves for wear or surface damage that could cause premature leakage.

Clean all cylinder components carefully before assembly and verify the installation direction of each seal, O-ring and backup ring. A damaged rod, worn bore or contaminated hydraulic system should be corrected before the rebuilt cylinder is returned to service.

Topvelsun Cylinder Seal Kit Supply

Topvelsun supplies excavator hydraulic cylinder seal kits through qualified supply channels with 1-piece MOQ and a 6-month warranty. For accurate fitment confirmation, send the OEM part number, excavator model, cylinder group or clear photos of the original seal kit before ordering.