803604509 boosting pump for XCMG ZL50G/ZL50GL Wheel Loader

product parameters

Product Name: Air Booster Pump
Part No.: 803604509
Applicable Model: XCMG ZL50G, ZL50GL Wheel Loader
Type: Air-over-hydraulic brake booster pump (Type A)
System Position: Between service brake air circuit and hydraulic oil circuit
Function: Pneumatic-hydraulic conversion, braking force amplification
Body Material: Metal pump body (subject to actual product)
Installation: Fixed at OEM mounting holes, connected to air/oil circuit interfaces
Working Condition: Quarry mining, aggregate yard, heavy earthwork and construction projects

Applicable Scenarios

Widely used in quarry, aggregate yard, and earthwork construction sites requiring frequent braking and heavy-load travel. It is a key actuating component for ensuring loader service braking force.

▪ OEM interface dimensions and mounting holes for direct replacement on ZL50G/ZL50GL
▪ Matches Type A booster specification, compatible with ZL50G/ZL50GL brake system air and oil interfaces
▪ Reliable air-hydraulic chamber isolation for rapid brake pressure build-up and responsive pedal feel
▪ Matched piston and seal assembly reduces air/oil leakage and cross-flow risk
▪ Pump body structural strength meets brake system working pressure requirements
▪ Can be stocked together with air brake valves, booster pump seals, and related brake accessories

FAQ 

Q：What are the symptoms of a failed air booster pump?
A: Common symptoms include spongy or sinking brake pedal, insufficient braking force, longer stopping distance, brake drag without return, or external air/oil leakage traces on the pump body. Inspect the booster pump first when these occur.

Q：Is insufficient braking force always caused by the booster pump?
A: Not necessarily. Check whether brake air pressure is normal (normal range 0.45–0.7MPa), the brake oil circuit lacks oil or has air ingress, brake caliper friction pads are worn, or the brake disc is contaminated with oil. Inspect the booster pump after confirming air circuit and brakes are normal.

Q：Can the booster pump be repaired?
A: Minor oil leakage may be addressed by replacing seals. If the piston seizes, cylinder wall is scratched, or air-hydraulic chambers cross-flow, replace the assembly directly for braking reliability.

Q：What to note after booster pump installation?
A：Bleed the brake oil circuit after installation and confirm pedal travel and brake pressure are normal. Verify no air leakage at air circuit fittings and no oil seepage at hydraulic fittings before putting into service.

Q：How to maintain the air booster pump daily?
A: Regularly check the pump body for air/oil leakage traces and smooth brake pedal return. During brake system maintenance, check booster pump seal condition and address aging or leakage promptly.