Hydraulic pump 20/903300 JCB 3CX/4CX 4-bolt, genuine

Hydraulic pump 20/903300, 4-bolt is a genuine JCB part for the JCB 3CX and 4CX backhoe loaders. The card also lists 7029121029.

This is the version of the pump with a four-bolt SAE B mounting flange and a splined shaft; it is used on JCB 3CX, 4CX and 4CN backhoe loaders. The flange type decides how the pump mounts on the machine: a pump with a two-bolt flange will not fit directly where a four-bolt flange is needed. The splined shaft fits the hub of the drive coupling; if the splines are worn, replace the coupling as well, or the new pump's shaft will soon be damaged too. The pump label carries the Parker model code and serial number, and the card lists both the Parker number 7029121029 and the JCB number 20/903300. The pump is heavy and should be supported with a suitable lift during removal and fitting. After the change, fill the pump with oil before the first start and bleed the system.

Specifications

Compatibility

Front section 33 cm³/rev, rear section 29 cm³/rev; according to seller data, a 1-inch 15-tooth splined shaft and clockwise rotation seen from the shaft end. Other parts are in Hydraulic pumps.

Fitting

Before changing the pump, drain and clean the hydraulic tank and renew the suction strainer and filters. Fit the new pump with the shaft and coupling cleaned and the splines lightly greased, and renew the flange seals. Before starting, fill the pump with clean oil, run the engine at idle to bleed the system and then check the pressures.