To repair or inspect the condition of parts, disassemble the power steering pump, control valve and power cylinder

Disassembly and inspection of the pump. Before dismantling, remove the pump (Fig. 1) from the vehicle, drain the oil, clean and rinse the outer surface of the pump

The procedure for disassembling and checking the pump is as follows:

- remove the tank cover and filters;

GAZ-66 power steering pump

  • - remove tank 5;
  • - install the pump so that its shaft is vertical and the pulley is at the bottom, and remove the cover 9 of the pump.

When removing the cover, keep the bypass valve 8 from falling out;

  • - mark the position of the distribution disk relative to the stator 11 and remove it from the pins;
  • - mark the position of the stator 11 relative to the pump housing 14 and remove the stator (the arrow on the stator indicates the direction of rotation of the pump shaft);
  • - remove the rotor 12 together with the blades. The stator, rotor and pump blades are selected individually at the factory, so their completeness cannot be violated during disassembly;

remove the pulley 1 (if necessary), the circlip and the pump shaft 13 together with the front bearing;

  • - check the free movement of the bypass valve in the pump cover and the absence of nicks or wear. The valve and pump cover are selected individually at the factory, so their completeness cannot be violated during disassembly;
  • - check the tightness of the safety valve seat 7 and, if necessary, tighten it;
  • - check the channels of the pump parts and clean them;
  • - check for scoring or wear on the end surfaces of the housing rotor and distribution disk. In case of minor scuffing or wear, rub these surfaces on the plate, then rinse the parts thoroughly;
  • - check if the blades 4 move freely in the grooves and if they are worn out;
  • - inspect the rubber seals. Hardened seals with cracks and other defects should be replaced.

When assessing the technical condition of the pump, keep in mind that the wear of individual parts, except for obvious scuffs, cannot serve as a basis for replacing them.

The technically sound condition of the pump is determined by two complex indicators:

  • - the maximum pressure that the pump creates, and the noise during operation.

Checking the pressure generated by the pump is described above.

Due to the difficulty of measuring the wear of the stator, rotor and pump blades, they must be measured in case of loss of pressure or obvious scuffing.

The pump rotor, stator and vanes are sorted at the factory into three length groups.

Parts of only one group are installed in the pump.

The selection of these parts by groups ensures high pump performance and obtaining the specified characteristics.

When repairing the pump, the rotor, stator and blades must also be replaced as a set. The manufacturer supplies such kits for spare parts.

The dimensions by which the rotor, stator and blades are sorted into groups are given in Table. 1.

The bypass valve spool and the pump cover are also selected as a set, for which they are sorted into three groups according to the diameters of the hole and the neck.

The dimensions by which the cover and spool are sorted into groups are given in Table. 2.

If the pump is noisy (a sound that stands out from the general noise background of the running engine), replace the ball bearing of the pump shaft.

When repairing the pump, keep in mind that the pump is unified with the pump of the ZIL-1Z0 car, except for the pulley and the bypass valve spring.

Assemble the pump in the following order.

Rinse and dry all parts thoroughly before assembly. Do not wipe the parts with ends and rags that leave threads, villi, etc. on the parts.

The same requirement must be observed when assembling the control valve and power cylinder.

Install the stator, rotor with vanes and distribution disc according to the marks made during disassembly and the arrow indicating the direction of rotation.

In this case, the chamfer of the slotted hole should face the pump housing

Install cover with bypass valve.

The hex of the seat must face the inside of the hole. Tighten the cover bolts evenly. The tightening torque of the bolts is 2.1-2.8 kgm.

The torque of the bolts securing the tank, 0.8—1 kgm.

The tightening torque of the nut securing the pump pulley is 5-6.5 kgm.

The pump shaft must rotate freely, without jamming.

Disassembly of the control valve must be done in the following order.

Drain the oil from the power steering system.

Disconnect pipes and hoses from control valve.

Power steering control valve

Remove cover 1 (fig. 2) of the control valve. Remove central bolt 5.

Remove the bolts securing the control valve body to the longitudinal link and remove the control valve.

Unscrew the adapter fastening screw and remove the adapter 18.

Remove the covers and cuffs from both sides of the valve.

Remove control valve spool 6.

If the bronze saddles are severely crumpled and deformed, then press them out and press in new ones.

Determination of the technical condition of valve parts.

On the working necks of the spool there should be no nicks, burrs or deep scratches, which, if necessary, should be cleaned with a finishing bar without filling up sharp edges.

The spool must move freely, without binding, in the valve body. In this case, it is necessary to clean two holes in the spool necks.

Sealing cuffs 4 and 7 must remain elastic, not have cracks, snags and other defects on the working surfaces.

Thoroughly rinse the internal cavities and channels of the valve body from dirt.

The spool and valve body do not wear out. If the valves are dirty, scoring and marks can form on their surface.

If scuff marks and risks cannot be removed with a bar, it is necessary to replace the parts.

The spool and valve body are sorted into three groups according to the diameter of the necks and holes.

Sizes of parts by groups are given in Table. 3.

Assemble the control valve in the following order.

Install the adapter 18 on the longitudinal rod (see Fig. 2) and tighten its fastening screw. At the same time, you need to make sure that there are no nicks and dirt on the mating ends.

Assemble spool 6, cuffs 4 and 7 and caps 3 and 20 in the valve body.

Lubricate the spool and cuffs with turbine or spindle oil before installation in the housing.

Insert the spool into the body without distortion, without applying force. The spool fits freely into the body when the direction is correct.

Assemble the valve body and spool according to the mating diameter of only one group.

On the body, the group number is embossed on the flange under the cover, and on the spool it is electrographed on the non-working neck.

When assembling, you need to pay attention to the fact that the outer neck of the spool of a larger diameter faces the longitudinal rod.

Accordingly, the cuffs also have different inner diameters and must be installed on their necks.

The bolts of the valve body are recommended to be finally tightened after tightening the central bolt 6 in order to avoid jamming of the spool.

After tightening these bolts, check the freedom of movement of the spool in the body.

Finger 10 of the steering arm together with the spool must move freely relative to the rod end (within 3 mm).

Install cover 1, replacing cork gasket 2.

If the hoses are not immediately connected to the valve, plug the places of their connection with plugs that prevent water and dirt from entering the valve.

Power Cylinder Disassembly

Before disassembling the power cylinder, it is recommended to check the freedom of movement of the piston rod from one extreme position to another.

Power Steering Power Cylinder

The cylinder is disassembled in the following order:

  • - Loosen locknut 5 (Fig. 3);
  • - unscrew the nut 6 fastening the head of the 7th cylinder;
  • - remove the head 7 from the cylinder together with the rod 2;
  • - remove the stem from the head;

If the ball joint is worn, disassemble the ball joint and replace the worn parts.

Determining the technical condition of cylinder parts

When determining the technical condition of the cylinder parts, check that:

  • - there were no scratches on the inner surface;
  • - piston rings fit around the entire circumference of the cylinder or to a cylindrical caliber - 50 mm in diameter;
  • -piston rings freely, without jamming, rotated in the piston grooves;
  • - there was no wear on the chrome-plated chrome-plated stem surface.

Especial care should be taken to inspect that part of the rod that, in the middle position of the rod in the cylinder, is in contact with the sealing assembly of the cylinder head.

In case of nadir and wear of the rod coating, repair it or replace it with a new one;

  • - there were no burrs in the hole for the rod in the head of the 7th cylinder;
  • - brass washers 12 were not deformed and sat on the stem with a small gap to scrape dirt from the stem;
  • - rubber cuff 10 was elastic and had no damage;
  • - felt gland 14 compressed the stem. If the felt gland does not compress the stem and is dirty, it must be replaced;
  • - rubber o-rings on the cylinder head indra retained elasticity. In case of hardening and large deformations of the rings, they must be replaced;
  • - washers and pads were not deformed;
  • - the correct hole was kept on the inner washer to ensure a stop against the stem collar.

Assemble the power cylinder in the following order.

Lubricate the rod with the piston and the inner surface of the cylinder with turbine or spindle oil during assembly.

Set the piston rings on the piston with locks in different directions.

Turn the nut 6 (see Fig. 3) of fastening the cylinder head all the way into the end of the cylinder and then lock it with locknut 5.

After assembly, check the freedom of movement of the rod in the cylinder.

The rod should move evenly, without jamming, under little effort (no more than 6 kg).

If installed, check the cylinder for oil overflow through the piston rings.

To do this, bring oil to nozzle 3 at a pressure of 80-90 kg/cm2 and measure the amount of leakage from the other cylinder nozzle.

Normal oil leakage should not exceed 360 g per minute.

Repeat the test by supplying oil under pressure to the second fitting and moving the stem to another extreme position. When checking, turbine oil 22 is used.

If the hoses are not immediately connected to the cylinder after assembly, it is necessary to plug the cylinder fittings with plugs to prevent water and dirt from entering the cylinder.

Tab. 1 Rotor, stator and blade dimensions by group

Part name



part length, mm


(sort by largest size)








(sort by largest size)








(sort by largest size)







Tab. 2 Hole diameters of the cover and neck of the spool by groups

Part name



diameter, mm


(sort by smallest size)








(sort by largest size)







Tab. 3 Bore and neck diameters of the spool and valve body by groups

Size name



diameter, mm

A hole in the valve body for the spool

(sort by smallest size)







Large spool necks

(sort by smallest size)