Maintenance of Hydraulic Tools

08028-0D/H5250/94.08.12

1) The hydraulic jacks require no maintenance except replacement of defective sealing rings, each of which consists of an o-ring and a back-up ring fitted in ring grooves in the piston and cylinder.

The piston and cylinder are easily separated by taking out the bleed screw and pressing the parts apart by means of working air.

Work.

air

Fig 1.

Make sure that there are no marks or scratches on the sliding surfaces of the parts. The presence of metal particles will damage the sealing rings.

2) The sealing rings are to be fitted with the o-rings nearest to the pressure chamber and with the back-up rings away from the pressure chamber.

Compression tool

Fig 2.

Fit the sealing rings and lubricate with clean lub. oil. The piston and cylinder are pressed together by means of the tool supplied. See that the rings do not get stuck between the piston and cylinder.

Pressure Testing of Hoses

To avoid working accidents caused by emission of pressure oil from the hydraulic hoses, the hoses should be pressure tested at 1200 bar once a year.

Note: During the pressure testing the hoses must be covered carefully.

08028-0D/H5250/94.08.12

08028-0D/H5250/94.08.12

L23/30H

Description:

Hand tools:

Starting position:

Related procedure:

1)Before the nuts are screwed on, the threads and the contact faces should be greased with copaslip or similar, the tightening torques being based on a coefficient of fiction in the threads.

2)The nuts should fit easily on the thread, and it should be checked that they bear on the entire contact face.

3)In the case of new nuts and studs, tighten and loosen the nuts 2 or 3 times so that the thread may assume its difinite shape, thus obviating the risk of loose nuts.

4)Nuts secured with a split pin are tightened to the stated torque and then to the next split-pin hole.

5)The following instructions apply to the use and maintenance of the torque spanner.

Torque Spanner

6) The handle of the torque spanner is provided with a scale indicating the torque at which the spanner can be set.

7)For setting the spanner at the torque required, there is a ball on a small arm at the end of the handle.

8)When pulling the ball with the arm outwards, a small crank handle is formed.

A spring-loaded slide in the handle provided with a mark which, when turning the crank handle, can be set at the required torque on the scale.

The torque spanner functions are as follows:

9)The above-mentioned spring activates a pawl system in the handle, and when using the spanner, this pawl system will be released when the pre-set torque has been reached, at which moment a small jerk is felt in the spanner and a small click is heard.

10)The torque spanner must not be used for torque higher than those stamped on it, and it must not be damaged by hammering on it or the like.

The tightening procedure for connecting rod screws can be executed with the tools originally delivered with the GenSets.

The enclosed pages illustrate tool combinations applicable to tightening of connecting rod screws.

It is also acceptable to execute the turning of the screws through a 60° angle, by means of a pneumatic impact spanner, with power and dimensions, if available.

Tool combinations for tightening of screws, see fig. 1.

The 24 mm socket to be used must be a socalled

1.Torque spanner, 80-360 Nm.

2.Ratchet, (only for tightening).

3.Socket, 24 mm.

Fig. 1. Tool combinations for tightening of screws.

specially designed for socket use with mechanical or pneumatic impact tools.

Compared to sockets for manually operated spanner, the power top has increased dimensions, see fig. 2.

The connecting rod screws are situated very closely, leaving only minor space between collars and hexagonals of the screw heads.

Dependent of the manufactures, it can be necessary to adapt the power top to the limited space conditions around the screws.

In such case only the absolutely necessary machining should be executed.

Connecting rod screws

Connecting rod

Special socket (power top)