Remanufactured air compressors have always been accepted within the bus and coach industry. With soaring fuel costs and corporate pressure to recycle wherever possible, it is an obvious route both for reducing costs and the company’s impact on the environment.. One reason that several UK national bus fleets are now specifying remanufactured compressors for their vehicles is that today’s products are produced to high standards that will deliver reliable in-service performance.

The best remanufacturing practices these days more closely resemble original equipment manufacturing, working to set documented procedures and tolerances. Components used in the remanufacturing process are obviously critically important, and must be at least as good as the OEM specification. Fleet Parts Ltd., use original, or equivalent quality internal components within our remanufactured Compressors.

We use proven long standing suppliers, and all new components are sent for analysis, to ensure they are at least equivalent to the O.E. Material, tolerances & specification. The component traceability control system should go hand in hand with an ISO approved certification. Use a reputable supplier and it is possible to not only trace the finished unit itself back to the assembly technician, but each component should also be traceable back to the supplier and particular batch that the goods were supplied against.

A Remanufacturer is in a unique position in that they are able to study the condition of the old compressors as they arrive. It is not inconceivable that the life of a compressor can be enhanced, by modifying the remanufactured compressor, as a result of those studies.

Demanding service

Bus applications in particular place great demand on air systems and, therefore on the compressors themselves. Because of this it is critical that the engineering and technical procedures of the remanufacturers are in good order. At Fleetparts, we have taken the boring and honing process a step further. We have developed a process to run-in the compressor, taking the peaks off the cross-hatching in the cylinder bore. This eliminates the need for the piston rings to do this job and means that the compressor is immediately ready for service.

Quality counts

Screen Shot 2016-09-07 at 11.17.18The valve seats are always recut, bringing them back to their original dimensions, and the cylinder head valve seats are always surface ground. Paying attention to the piston and rings is critically important. Some remanufacturers cut costs here by using cheaper components, but this will result in the reduced performance and life of the compressor. Of equal importance are the cylinder head reed valves and valve discs. Reed valves are subject to extreme heat and stresses, so it is necessary to closely control the quality with tight batch control and certificates of conformity.

Testing, testing…

Once the compressor has been rebuilt, it undergoes tests to check its performance. The crankshaft must rotate freely and there should be no tight spots. There should, however, be a noticeable backlash at the top and bottom of each stroke. A pressure test of the cooling system will ensure the unit is leak free, which includes leakage into the cylinders. The air Intake / delivery function is tested to establish the correct suction of the Inlet, and compression of the delivery ports. Final batch tests are carried out on an electronic dynamic compressor test bench, which fully simulates the compressor function.

A proven pedigree in Air Brake Compressor Remanufacture

Fleet Parts have remanufactured Air-Brake Compressors for over 40 years. All components used in the remanufacture of Fleet Parts Air-Brake Compressors are sourced from long standing suppliers. Inlet & Delivery Reed Valves are supplied by O.E. manufacturers such as HOERBIGER.

In order to achieve the optimum performance from our compressors, our Bores are finished to O.E. standards. We use a Profilometer to ensure that the surface finish remains consistent. An increased Roughness Average (Ra) can lead to oil passing the Piston Rings, whereas a significantly decreased Ra will prevent the Cylinder walls from being able to retain sufficient lubrication, which will lead to premature wear of the Bore & Rings, and even possible seizure. Fleet Parts use the latest Sunnen automatic Computerised Programmable Honing Machine to achieve the ultimate finish.

We have submitted samples of our finished Bores to Sunnen the Industry Experts, for an independent test & report. Their opinion was that Fleet Parts Honed & Plateau Finished Bores were consistent with the finish achieved by OEM Manufacturers.

All Bores are also checked for Roundness by our Engineers.