| Conditions | Possible Causes | Corrections |
| Low or no pressure to brake | - Empty fluid reservoir.
- Damaged hydraulic system.
- Leakage of brake actuation fluid.
| - Fill reservoir to correct level with specified fluid.
- Repair hydraulic system.
- See “Internal Leak” and “External leak” on page 30.
|
| Vehicle does not move | - Damaged hydraulic system.
| Repair hydraulic system. |
| Brakes dragging | - More than 20 psi (1.4 bar) pressure applied when brakes released.
- Damaged piston return spring assembly.
- Piston not returning.
- Wrong cooling and/or actuation fluid used.
| - than 20 psi (1.4 bar) when brakes released and while machine is operating in any mode.
- Repair or replace piston return spring assembly.
- Check piston seals and seal separator for swelling or damage. Replace as necessary.
- Check piston seals and seal separator for swelling or damage. Replace as necessary.Purge system and use specified fluid.
|
| Noticeable change or decrease in stopping performance
| - Inadequate actuation fluid supply to brakes.
- Inadequate pressure to apply brakes.
- Worn or damaged discs.
- Overheated seals and/or discs.
- Dirty or contaminated cooling fluid.
| - Replenish fluid in brake system. Check for leakage and correct cause.
- Check brake apply system. Check for leakage in brake system or brakes, and correct cause.
- Inspect and replace discs if necessary.
NOTE: As disc wear occurs, make sure brake system can supply adequate fluid to fully apply brakes.
- Inspect and replace discs and seals if necessary.
- Drain and flush cooling fluid from brakes and entire brake system. Replace with approved fluid. In some cases, it may be necessary to replace discs. Clean or replace filter.
|
| Brake does not fully apply | - Empty fluid reservoir.
- Damaged hydraulic system.
- Leakage of brake actuation fluid.
| - Fill reservoir to correct level with specified fluid.
- Repair hydraulic system.
- See“Internal Leak” and “External leak” on page 30.
|
| Brakes feel spongy/soft | Brakes or brake system not properly bled.
| Bleed brakes and brake system. |
| Internal leak: Fluid bypasses seals into brake cavity and leaks out housing at face seal joint and/or fills axle with fluid bypassing spindle-to-hub seal and blows out breather
| - Worn or damaged piston seal.
- Melted or extruded piston seals.
- Corrosion, pitting, wear or other damage, marks, scratches to piston and/or brake housing bore in area or seal/sealing lips.
| - Replace piston seals.
- Correct cause of overheating and replace seals.
- Clean, smooth, rework or replace affected parts.
|
| External leak | - Loose bleeder screw.
- Loose inlet fitting or plugs.
- Damaged inlet fitting or plugs or damaged seats.
| - Tighten bleeder screw to 15-20 lbs. ft.(20-27 N·m).
- Tighten inlet fitting to 25-35 lbs. ft.(34-47 N·m).
- Replace inlet fitting or plug and o-ring if used. Repair or resurface area; or replace as necessary.
|
| Coolant leaking out of brake housing
| - Face seal damaged, worn or improperly installed.
- Loose drain plug, fill plug, forced cooling plug, or other fittings or hydraulic connections to brake.
- Damaged plug.
- Deteriorated or inadequate sealant used at joint.
- Pressure in cooling cavity too high.
| - Reinstall and/or replace face seal.
- Tighten plugs, fittings, connections.
- Replace plug.
- Disassemble, clean, re-seal and reassemble joint.
- Make sure cooling system does not produce more than 15 psi (1 bar) normal (or 20 psi [1.4 bar] intermittent pressure spikes) into brake cooling cavity.
|
JIANG
