Spring energy accumulator of the ZIL-5301 parking system

The drive of the parking brake system uses a spring energy accumulator (Fig. 1) designed to actuate the brake mechanisms of the rear wheels when the parking brake system is activated

A strong spring is compressed in the cylinder, so if you disassemble the spring energy accumulator incorrectly and carelessly, you can get injured.

To disassemble the spring energy accumulator, it must be removed from the bracket by disconnecting the air supply tube.

Spring energy accumulator: 1 - flange; 3 - pipe; 4 - cylinder; 7 - power spring; 8 - screw; 9 - piston; 10 - ring; 12 - bearing; 13 - thrust ring; 14 - bolts; 15 - nuts; 17 - rubber sealing ring; 18 - pusher; 19 - protective cover;

Install and secure the energy accumulator in a vice with soft jaws by flange 1 with pusher 18 up and remove the rubber boot 19.

Heat pusher 18 to a temperature of 200 °C and unscrew it with a special socket wrench.

Supply air under pressure of at least 0.5 MPa into the energy accumulator.

Insert a special split mandrel, model I 804.00.008, into pipe 3 and, pushing bearing 12 down with it, remove the thrust ring 13.

Remove the energy accumulator from the vice and, turning the cover with the flange down, remove the thrust ring 13 of the bearing, bearing 12 and ring 10.

Device for disassembling and assembling a spring energy accumulator

To further disassemble the energy accumulator, it must be installed in a special device model I 804.33.000 (Fig. 2) and screw 1 to compress the power spring 7 (see Fig. 2).

Then unscrew bolts 14 with a spanner wrench, holding nuts 15 with another wrench.

After this, being careful, unscrew the screw of the device and remove cylinder 4, spring 7, piston 9 and, if necessary, unscrew screw 8.

It is strictly forbidden to unscrew the bolts 14 securing the energy storage cylinder outside the device.

After disassembling the parts of the brake spring energy accumulator, wash them with clean gasoline or acetone, dry them and carefully inspect them.

Cracks, hairlines and other defects visible to the eye are not allowed on the surface of body parts.

Parts must be cleaned of rust and burnt marks. All rubber parts must be replaced.

To assemble a spring energy accumulator, you need to install flange 1 on a special device and insert piston 9 into it with tube 3 down.

Next, install the power spring 7 with a tapering loop to the piston, centering the spring on the spring plate 20 so that the ground part of the spring is in the sector of the plate, which has internal and external flanges, and cover it with cylinder 4 so that the drain tube pipe is in the middle between flange bosses 1.

Compress spring 7 with the screw of the device and secure cylinder 4 to the flange with bolts 14 and nuts 15.

Unscrew the screw of the device, remove the energy accumulator from it and secure it in a vice to flange 1.

Turn the energy accumulator in a vice 180° and supply it with air at a pressure of at least 0.5 MPa.

Checking the spring energy accumulator

Install ring 11 into tube 3, seating it with mandrel I804.00.008, needle bearing 12, thrust ring 13, orienting it with the chamfer upward, and thrust ring 11.

Bleed the air from the energy accumulator and unscrew and screw in the release screw 8 three times, while observing whether tube 3 is supplied, that is, whether the thrust ring 13 is installed correctly.

After normal release of the brake has been ensured, you need to re-tighten screw 8 and tighten it to a torque of 40-50 Nm;

Re-inject air under pressure of at least 0.5 MPa into the energy accumulator, visually check the correct installation of the thrust ring 13, put the rubber o-ring 17 on the pusher 18, apply a drop of anaerobic sealant to its threads and tighten the pusher 18 with a torque of 40-50 Nm into the handset 8.

Remove excess sealant with a napkin.

Place protective cover 19 on flange 1 and pusher 18.

To check the spring energy accumulator after assembly, install it on the stand and connect it according to the diagram shown in Fig. 3.

In this case, the release screw 8 (see Fig.↑ 1) must be screwed in all the way.

Submit three times and release air under pressure of 0.75 MPa into terminal 1. Check the stroke of the pusher.

To check the shut-off pressure of the spring energy accumulator, it is necessary to reduce the pressure in terminal 1 to 0.48-0.54 MPa. In this case, the pusher can move no more than 5 mm

The tightness of the spring energy accumulator is checked by saponifying the joints and by the absence of air leakage from the drainage pipe in the static position of the pusher (the parking brake valve handle is in the “movement” position).