Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Genie GS-2668 RT Brake Dragging Resolved
#1
Brake Dragging Symptoms
A common issue surfaced when the Genie GS-2668 RT rough-terrain scissor lift—typically weighing around 2,891 kg (6,374 lb) with a platform capacity of 567 kg (1,250 lb) and a working height of approximately 9.9 m (32.8 ft) —was driven and found to be exceedingly slow, as though the brakes were constantly applied. The machine's sluggishness suggested a brake release failure, even though the electrical diagnostics and control circuits seemed functional. A manual override pump likewise failed to fully free the brakes .
Brake System Overview
The GS-2668 RT employs a hydraulically actuated brake system, where a solenoid-controlled valve channels hydraulic pressure to release the wheel brakes. When functioning correctly, the brakes remain engaged when at rest but fully release when pressure is applied via either the electrical control or the emergency hand pump. Without sufficient release pressure, the machine moves slowly, or stalls even under engine power.
Likely Causes of Brake Stick
Evidence points to two potential culprits:
  • Insufficient Hydraulic Pressure: The hand pump release or solenoid may not supply enough pressure to retract the brake pads. Without a reference pressure from the manual—absent from the available documentation—this is hard to verify .
  • Internal Hydraulic Blockages or Valve Issues: Contaminants in the brake fluid or stuck valves can prevent adequate pressure build-up, preventing full brake release.
Troubleshooting Steps
While a precise pressure spec wasn't available, here’s a practical protocol that technicians recommend:
  • Attach a precision pressure gauge near a brake line to measure release pressure both via the solenoid and hand pump. Aim for pressure high enough to clear mechanical brake engagement.
  • Inspect the brake fluid filter for debris or metallic particles, which may impair fluid flow and reduce pressure—clearing or replacing the filter and bleeding the system can restore proper release force .
  • Bench-test the solenoid valve to confirm it’s actuating adequately and not partially blocked.
  • Verify hydraulic connections and line integrity, ensuring hoses are not kinked or leaking.
  • Use the service manual’s schematics (part number 112657) to locate test points and confirm pump outputs—this manual covers the GS-2668 RT and is available through Genie .
Operator Tips & Real-World Insight
Many machine service professionals note that disassembly isn’t always needed: if the pump produces strong pressure and the solenoid clicks clearly, the issue often lies within a contaminated filter or a sticky valve. Cleaning these components under proper hydraulic bleed procedures usually restores normal function.
Preventive Maintenance Suggestions
  • Conduct scheduled brake system flushing, ideally every 2,000 hours or at intervals specified by Genie’s maintenance schedule .
  • Replace brake fluid and filters regularly to guard against contamination and wear.
  • Test hand pump operation during routine service to catch pressure loss early.
  • When trouble arises, reference the service manual for detailed hydraulic schematics and ensure pressure values align with specifications.

Summary Table:
  • Symptom: Machine slow to drive → brakes likely stuck.
  • Probable Cause: Insufficient hydraulic release pressure.
  • Checks: Solenoid valve actuation, hand pump output, pressure at wheel line, brake filter condition.
  • Fix: Clean/replace filter, bleed fluid, repair valve or pump as needed.
  • Maintenance: Regular hydraulic fluid/filter replacement, manual pump testing, schematic reference.
Reply


Possibly Related Threads…
Thread Author Replies Views Last Post
  Case 580SL Brake Failure and Rear Axle Diagnostics MikePhua 0 3 2 hours ago
Last Post: MikePhua
  Genie Z45/22 Torque Hub Hydraulic Leak and Housing Crack MikePhua 0 5 2 hours ago
Last Post: MikePhua
  Chain Case Failures and Brake Pin Damage in the Case 1845C Skid Steer MikePhua 0 5 7 hours ago
Last Post: MikePhua
  Troubleshooting Air Brake Issues on the 1999 International 4700 MikePhua 0 6 7 hours ago
Last Post: MikePhua
  Diagnosing Park Brake Release Issues on the Caterpillar D6H Dozer MikePhua 0 8 7 hours ago
Last Post: MikePhua
  Freeing Stuck Brake Shoes on a Terex TS14 Scraper MikePhua 0 5 7 hours ago
Last Post: MikePhua
  CAT E240 Track Brake Issues During Tramming: Causes and Solutions MikePhua 0 6 7 hours ago
Last Post: MikePhua
  Hidden Brake Failures in Air Systems and How to Catch Them MikePhua 0 1 8 hours ago
Last Post: MikePhua
  Troubleshooting Issues with Genie Z60/34 Manlift Basket Controls MikePhua 0 4 8 hours ago
Last Post: MikePhua
  Komatsu PC220 Travel Jerks and Brake Pulses MikePhua 0 4 8 hours ago
Last Post: MikePhua
  Genie TMZ-50/30 Boom Lift Troubleshooting and Legacy MikePhua 0 1 9 hours ago
Last Post: MikePhua
  Troubleshooting Brake Pressure Loss in the CAT D8T MikePhua 0 7 10 hours ago
Last Post: MikePhua
  Why Is 4x4 Not Engaging on a Genie S-85 Boom Lift MikePhua 0 6 10 hours ago
Last Post: MikePhua
  Genie S-600 Boom Lift Platform Overload Triggers Intermittent Control Lockout MikePhua 0 3 10 hours ago
Last Post: MikePhua
  Bobcat 435 Mini Excavator Swing Failure Linked to Brake Assembly and Hydraulic Restriction MikePhua 0 2 11 hours ago
Last Post: MikePhua

Forum Jump:


Users browsing this thread: 1 Guest(s)