Brake valve for parking brake system ZIL-5301

The crane can be installed to the right of the driver's seat or on the instrument panel

The air coming out of the faucet during braking is vented to the outside through the air duct connected to the atmospheric outlet II

Dismantling, assembling and adjusting the crane

Install the faucet in a vice with soft jaws and fasten it to body 1 (Fig. 1) with cover 5 up. Unscrew axles 9 of rollers 11, holding cover 5 with your hand, and remove it with spring 16.

Device (a) and parts (b) of brake valve for parking brake system

Then, using a core, being careful, knock out pin 4 and remove the stem cam 7 with a washer.

Using round-nose pliers, remove the thrust ring 17 and remove the stem guide 18, springs 2 and 29, spring plate 19 and stem 8 from the housing 1.

Release the valve body 1 from the vise and remove the piston 15 with the valve 14 as an assembly using a wooden mandrel inserted through the atmospheric outlet III.

To disassemble the valve 14 from the piston 15, it is necessary to remove the thrust ring 20 with round-nose pliers, holding the piston 15 in your hand and being careful, since there is a compressed conical spring 21 in the piston.

After disassembling the parts of the brake valve of the parking brake system, rinse with clean gasoline or acetone, dry and carefully inspect.

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

Details must be cleaned of rust and burn marks. All rubber parts must be replaced with new ones. Paint the springs with varnish or paint.

Before assembling the crane parts, lubricate with a thin layer of TsIATIM-221 lubricant by hand.

Assembly of valves, rubber o-rings and other rubber parts must be done carefully to prevent damage. The presence of scratches, cuts and other defects on the surface of these parts is not allowed.

The assembly of the valve must begin with the subassembly of the valve 14 with the piston 15, placing it on a flat table.

Install valve 14, support washer 23 into the piston, orienting it with the flare to the rubber element of the valve, conical spring 21 and using round-nose pliers thrust ring 20.

Then it is necessary to clamp the body 1 in a vise and install the piston 15 complete with the valve 14 into it (see Fig. 1). Install spring 2 with plate 19.

Assemble stem 8 with washer, spring 2, plate 19 and install it in body 1. Then install spring 24 and stem guide 18, paying attention to the presence of a rubber sealing ring on it.

Connection diagram on the parking system brake valve test bench

After that, if necessary, you can adjust the force of spring 2 (see Fig. 2). to do this, it is necessary to compress the spring 2 to the size x = 13.8÷13.9 mm from the upper end of the housing 1 to the upper end of the plate 19. In this case, the spring force should be equal to 130÷155 N.

If this force is less than the specified value, then install shims (parts 100-3537095 or 100-3537097), bring the spring force to the required value.

Installing washer 1003537095 increases the spring force by 42.5 N and provides a pressure drop of 0.035 MPa, and installing washer 100-3537097 increases the force by 22.5 N and 0.021 MPa, respectively.

After adjusting the springs, put on the stem cam 7 and, being careful, install pin 4 into the stem 8 using a core.

Next, install the spring 16 and the cover 5, after inserting the rollers 11 into it. Screw the two axles 9, securing the cover 5 with them.

Measure the minimum gap between cover 5 and washer 22, which should not exceed 0.15 mm.

If this gap is greater, then the shims are det. 100-3537092 0.15 mm thick, part no. 100-3537093 0.2 mm thick and det. 100- 3537094 0.3 mm thick, combine and put on washer 22 between cover 5 and body 1 so that the gap does not exceed the specified value.

Washer 22 children. 100-3537091 0.5 mm thick remains at the bottom. Washers should be lubricated with CIATIM-221 grease.

Check the ease of returning the handle to its original position when it is deflected at an angle of 40÷45° and 65÷70°.

Checking the crane performance

Install the valve on the test bench and connect it according to the diagram shown in fig. 2.

Supply air at a pressure of 0.75 MPa to the outlet, while the pressure in outlet 1 should be equal to the pressure in outlet 1.

Turn the tap handle three times from position 1 to position 3 and back.

Then slowly turn the tap handle from position 1 to position 3. When moving the handle, there should be no jamming and it should be easy! lock in position 3.

When turning the handle from position 1 up to 70°, it should automatically return to position 1.

Slowly turnmove the handle from position 1. When the handle is turned by 8…10°, a pressure drop should occur in port II, but not more than 0.15 MPa.

As you turn the handle further, the pressure in port II should gradually decrease to 0.

To check the faucet for leaks, it is necessary to supply air at a pressure of 0.75 MPa to outlet I at handle positions 1 and 3. When washing, the appearance of air bubbles is not allowed for 1 minute.