WABCO System Saver 318

Questions and Answers

K
Katherine OwensJul 31, 2025
How to fix excessive oil in WABCO System Saver 318?
- M
  Marie ShepardJul 31, 2025
  To address excessive oil in your WABCO Air Compressor, start by cleaning oil drain passages in the compressor and on the engine surface, ensuring correct alignment. Replace a damaged, defective, or dirty engine air filter, and repair any leaking compressor air intake components. Change the engine lubricating oil, adhering to the vehicle manufacturer's oil and filter maintenance schedules. Check the engine or compressor air cleaner, replacing it if needed, and repair any kinks or excessive bends in the compressor air inlet. Verify the engine crankcase venting meets the manufacturer’s specifications. Inspect the system for leaks and repair them. If the issue continues, consider replacing the compressor.
D
devin40Aug 9, 2025
Why does WABCO System Saver 318 continuously cycle?
- K
  Kathy GrayAug 9, 2025
  If your WABCO Air Compressor continuously cycles, check for air leakage with the compressor unloaded. If leaking, replace the cylinder head. For governor air leaks and dryer purge valve air leakage, refer to the manufacturer’s manual for maintenance and troubleshooting procedures. Inspect the governor-compressor attachment and alcohol injector connection for physical damage and repair. Drain reservoirs of excessive contamination. If the issue persists, replace the compressor.
D
Danielle KellyAug 13, 2025
How to fix WABCO Air Compressor head gasket failure?
- H
  hannahhillAug 13, 2025
  To fix a WABCO Air Compressor head gasket failure, check for traps (low spots) in the lines and repair them. Clear the discharge line and replace it if necessary. If carbon build-up is present, replace the discharge line. Clear a frozen or blocked line to the governor, replacing it if necessary, and check for air dryer malfunction, repairing or replacing as required. Consult the air dryer manufacturer’s manual for service information. Repair or replace the governor, referring to the governor manufacturer’s manual. Inspect the gasket and replace it if necessary. Verify all bolts are correctly torqued. If the problem persists, replace the compressor cylinder head assembly.
W
William BarnesAug 18, 2025
What causes WABCO Air Compressor to leak coolant?
- J
  James BarnettAug 18, 2025
  If your WABCO Air Compressor is leaking engine coolant, check the fittings at the compressor and engine for leaks and verify they are correctly torqued. Replace the cylinder head if there is a cracked coolant port or porosity in the cylinder head. Verify cylinder head bolts are correctly torqued and adjust as necessary. Inspect the gasket internal to the cylinder head for cracks or signs of wear, replacing if necessary. If the issue persists, replace the compressor.
M
Michelle BuckAug 21, 2025
Why is WABCO System Saver 318 pressurizing coolant system?
- A
  amandachambersAug 22, 2025
  If the WABCO Air Compressor is pressurizing the coolant system or there's coolant leakage to the compressor inlet, inspect the gasket internal to the cylinder head and replace it if necessary. Replace the cylinder head if there is cavitation or corrosion, porosity, or cracks in the cylinder head. If the issue persists, replace the compressor.
M
mooresherylAug 27, 2025
How to fix unloader leakage in WABCO Air Compressor?
- M
  Maurice PriceAug 27, 2025
  To address unloader leakage in your WABCO Air Compressor, replace the compressor cylinder head assembly. This may resolve possible internal damage, including a worn or damaged unloader piston O-ring, porosity in the unloader piston bore, or a loose or leaking seal at the unloader piston bore.
B
Barbara DavisNov 4, 2025
What to do if WABCO Air Compressor has no air delivery?
- D
  Douglas RomeroNov 4, 2025
  If your WABCO Air Compressor isn't delivering air, has low air delivery, or low air pressure, check for freeze-up in the discharge line and eliminate any traps. Inspect and repair the compressor discharge port, clearing any line restrictions, and replace damaged lines. Inspect the compressor air induction line for kinks and restrictions, repairing or replacing as necessary. Check the governor for correct loader/unloader cycles, referring to the vehicle manufacturer’s manual for governor maintenance. Replace broken or dirty air filters and clean contaminants from the compressor surface. Check the air dryer for malfunction. Replace faulty sections of the discharge line. Ensure all air line connections are secure, tightening to vehicle specifications. Inspect the cylinder head for damaged por...

Summary

Service Notes

About This Manual

Provides service and repair procedures for the WABCO System Saver 318 air compressor.

Before You Begin

Instructions and precautions before starting service, including reading warnings and using special tools.

Hazard Alert Messages and Torque Symbols

Explains WARNING and CAUTION symbols and torque indicators for safety.

How to Obtain Additional Maintenance and Service Information

Information sources for further maintenance and service details.

How to Obtain Tools and Supplies Specified in This Manual

Contact information for obtaining necessary tools and supplies.

Introduction

Application

Details on where the System Saver 318 air compressor is used, including non-through drive and through-drive versions.

Description

Explains the WABCO System Saver 318 air compressor's function and its two major subassemblies.

Operation

Describes how the compressor is driven and how compression is controlled by the governor and unloader mechanism.

Maintenance Intervals

Recommends following engine manufacturer guidelines for fluid levels, air filters, and change intervals.

Visual Inspection

Describes visual checks for detecting minor problems as part of preventive maintenance.

Troubleshooting

Hazard Alert Messages

Emphasizes reading and observing hazard alert messages for safety during troubleshooting.

Compressor Replacement

Hazard Alert Messages

Reiterates safety warnings for personal injury and pressure release before disconnecting components.

Compressor Replacement Information

States cylinder head is replaceable, but crankcase is not, requiring complete compressor replacement if damaged.

Removal

General steps for removing the compressor from the vehicle, including draining systems and disconnecting lines.

Cylinder Head Removal

Steps to remove the cylinder head from the crankcase after the compressor is removed from the engine.

Cylinder Head Installation

Detailed steps for installing cylinder head valve components, sliding leaf, inlet valve, and cylinder head.

Testing

Procedures for testing the vehicle air system after compressor installation, including governor cutout and unloading.

Air System Leakage Test

Steps for performing an air system leakage test according to North American Uniform Roadside Inspection Criteria.