TROUBLE SHOOTING
Note. See the TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL INFORMATION section.
HYDRAULIC SYSTEM PRESSURE TEST
- Ensure belt tension is correct. Disconnect high pressure line from power steering pump. Connect Power Steering Pressure Gauge (J-5176-D) hose to power steering pump fitting. Connect other hose from valve side of tester to steering gear inlet.
- Open valve on pressure gauge. Check fluid level and add fluid as necessary. Check for possible leaks at pressure gauge connections. Bleed air from system. See «HYDRAULIC SYSTEM BLEEDING»(ref-55503-S38234718402001011700000) under LUBRICATION. Run engine until fluid reaches normal operating temperature of 150-170°F (66-77°C). Check fluid level and add fluid as necessary.
- Note pressure reading with valve open and engine idling. Pressure should be 80-125 psi (6-9 kg/cm 2 ). If pressure exceeds 200 psi (14 kg/cm 2 ), check hoses for restrictions and poppet valve for proper assembly. CAUTION: To prevent pump damage, DO NOT hold gauge valve closed for more than 5 seconds.
- Completely close and open valve 3 times. Record highest reading each time. Readings should be within specification. See «PRESSURE TEST SPECIFICATIONS»(ref-55503-S14890543312001011700000) table.
- If pressure readings are within specification and within 50 psi (4 kg/cm 2 ) of each other, pump is operating properly.
- If readings are within specification but not within 50 psi (4 kg/cm 2 ) of each other, flow control valve in pump is sticking. Remove valve, but DO NOT disassemble it. Clean valve. Flush system if dirty.
- If pressure is constant but more than 100 psi (7 kg/cm 2 ) below specification, clean or replace flow control valve in pump. If readings are still low, replace pump.
- If pressure readings are as specified, turn steering wheel from stop to stop with valve open. Record highest pressure with wheels at both stops. If highest pressure is not equal to highest pressure recorded in step 2), steering gear is leaking internally. Repair or replace assembly.
- Turn engine off. Remove tester. Reconnect pressure hose. Check fluid level. Bleed hydraulic system. See procedures for «HYDRAULIC SYSTEM BLEEDING»(ref-55503-S38234718402001011700000) under LUBRICATION.
| Application | Psi (kg/cm 2 ) @ Idle | Relief - psi (kg/cm 2 ) |
|---|---|---|
| C1500/2500 & 4WD | 80-125 (6-9) | 1200-1300 (84-91) |
| C3500 | 80-125 (6-9) | 1465-1515 (103-106) |
| C3500 (With Hydro-Boost) | 80-125 (6-9) | 1350-1450 (95-102) |
PRESSURE TEST SPECIFICATIONS
Inspection
Clean components using solvent, and blow dry. Avoid wiping valve components using cloth. Lint may cause binding of mechanism. DO NOT steam clean hydraulic parts.
Inspect bearings and races for scoring, pitting and wear. Inspect adjuster plug threads for damage.
- Clean components using solvent, and blow dry. Inspect stub shaft for nicks and burrs. Remove nicks and burrs using crocus cloth if possible. Inspect shaft pin for wear and cracks.
- Check valve spool fit in valve body. Remove nicks and burrs using crocus cloth if possible. Lubricate valve spool with power steering fluid. Rotate valve spool in valve body. If valve spool does not rotate freely, replace complete valve and stub shaft assembly.
- Valve assembly is balanced during assembly. If replacing any components other than rings or seals, replace complete valve and stub shaft assembly.
Clean components using solvent, and blow dry. Inspect rack piston grooves for scoring. Inspect ball bearings for damage. If any ball bearings are damaged, replace entire set. Check ball guides for cracks or dented ends. Inspect rack piston teeth for chips, cracks, dents and scoring. If rack piston is damaged, replace rack piston and worm shaft as an assembly.
- Clean all pump components with solvent and blow dry. Inspect flow control valve assembly for wear, scoring, burrs and other damage. Inspect seal bore for burrs, nicks and score marks.
- Inspect machined surfaces of body for scratches or burrs. Check "O" ring mating surfaces. Inspect drive shaft for excessive wear.
- Inspect pump ring for roughness. Check thrust plate and pressure plate for scoring and wear. Ensure vanes slide freely but fit snugly into slots. If vanes are loose in slots, replace rotor and/or vanes.
Clean all parts in power steering fluid and dry with compressed air. Inspect pressure plate, pump ring, vanes, thrust plate and drive shaft for scoring, pitting or chatter marks. Replace any damaged parts.
Scheme 5
Scheme 6
- Lubricate NEW drive shaft seal with power steering fluid and drive seal into pump housing using Seal Driver (J-7728). (Scheme 5)
- Install pump ring dowel pins into pump housing. Assemble thrust plate and pump rotor onto drive shaft. Fit NEW retaining ring to shaft. (Scheme 6)
- Install drive shaft subassembly into pump housing. install vanes into pump rotor. With holes positioned correctly onto dowel pins, install pump ring into pump housing.
- Lubricate NEW "O" ring with power steering fluid and install into pump body. Install pressure plate and pressure plate spring.
- Lubricate NEW "O" ring with power steering fluid and install into end cover. Lubricate outer edge of end cover with power steering fluid. Press end cover into pump housing. When installing retaining ring into groove, ensure opening of ring is near access hole in pump housing. (Scheme 7)
