Description

Case 21E, 121E, 221E, 321E Series 3 Wheel Loader Manual

Loader Model: 21E, 121E, 221E, 321E Series 3
Publication Number: 87734636C & 87734636A
English
May 2008
Format: PDF

Case 21E, 121E, 221E, 321E Series 3 Loader Service Manual – 489 Pages & 488 Pages

Manual Table of Content:

• Content
• Introduction
• Engine
• Front Axle
• Rear Axle
• Brake System
• Hydrostatic Drive
• Frame
• Steering
• Heating and Airconditioning
• Electrical System
• Working Equipment

Manual Extract: BRAKE ACCUMULATOR

As regards their operation, the accumulators are identical, they are membrane-type and ensure a certain number of activations of the connected users in case of hydraulic pressure lack.
The membrane accumulator consists of a pressure resistant steel container, inside which a membrane made of elastic material is assembled as separating element.

The membrane is locked with a ring nut between the body lower and upper part. In the membrane central lower section is dived a metallic disc preventing its slipping out from fluid inlet port.
Without hydraulic pressure, the membrane, loaded on the gas side to precharge pressure (P0), leans against the inner surface of the accumulator and the poppet stops the liquid flow.

With hydraulic pressure applied, the precharge pressure is exceeded by compressing nitrogen, the poppet is lifted and liquid flows into the accumulator. The useful quantity of liquid results from the difference between gas volume and minimum and maximum service pressure.