1. General For cleaning, use a non-aggressive, acid-free solvent with corrosion inhibitor.
Clean engine oil should be used to lubricate components unless otherwise specified.
This manual is written for a single cylinder compressor. For two-cylinder compressors, references to components should be read as plural and actions should be duplicated as appropriate.
Caution!
If components are damaged during disassembly and/or assembly, Robur Bremse will not be liable and will not accept any claim for warranty costs on the compressor. Any disassembly will void the compressor warranty.
2. Replacing a Cylinder Head or Head Gasket Service parts/kits required:
Complete cylinder head, gasket kit.
When replacing a cylinder head, always replace both the cylinder head-to-valve plate gasket and the valve plate-to-crankcase gasket.
Replacing a cylinder head (as a single part or as a preassembled part in the case of an energy efficient compressor) requires careful disassembly to overcome the adhesive force between the cylinder head gasket and the mating surfaces.
If the cylinder head or valve plate is not being replaced, clean the gasket contact area without creating scratches that could cause leakage problems later.
Install the new cylinder head gasket and then the cylinder head.
Lubricate the cylinder head bolts.
Insert the cylinder head bolts and tighten them in two stages according to the sequence shown in the diagrams below. First tighten them to a torque of 15 to 20 Nm. Repeat the sequence, tightening to a final torque of 30 to 33 Nm.
3. Replacing a Valve Plate
Required service parts/kits:
Complete valve plate, gasket kit.
To replace a valve plate, first remove the cylinder head assembly (with the cooling plate, if installed), the valve plate-cylinder head gasket, and, depending on the design, the valve plate-crankcase gasket or combined inlet reed valve/gasket.
Care should be taken to overcome the adhesive force between the valve plate gasket and its mating surfaces. Carefully clean the top of the crankcase to remove any dirt or metal burrs without creating scratches that could cause leakage problems later.
Clean the piston crown if the piston is not being replaced.
Regardless of their condition, the gaskets should be replaced.
Some models are equipped with a screw that attaches the valve plate to the crankcase, and some are equipped with a screw that attaches the valve plate to the cylinder head. In these cases, carefully clean the bolt, lubricate the threaded area, and tighten to a torque of 11.4 to 12.6 Nm.
Install the new valve plate-crankcase gasket on the crankcase, then install the inlet reed and any spacer, making sure it is properly seated and that the inlet reed is not pinched. Install the new valve plate and valve plate-head gasket.
Finally, reinstall the cylinder head.
4. Replacing a Piston
Service parts/kits required:
Piston assembly, gasket kit.
Replacing a piston requires disassembly of the connecting rod cover to remove the piston/connecting rod assembly. The connecting rod cap is accessed through the sump plate opening, and before removing the cap, note which way it is mounted relative to the connecting rod.
The piston/connecting rod assembly can now be removed through the top of the crankcase.
Remove the circlips holding the gudgeon pin in the piston, then withdraw the gudgeon pin to separate the piston from the connecting rod.
Lubricate the gudgeon pin, insert the connecting rod into the new piston, and insert the gudgeon pin.
Mount the circlips holding the gudgeon pin and make sure they are properly seated in the grooves of the piston. Install the piston rings on the piston if not already installed.
Clean the crankcase bore, taking care to remove any dirt or metal burrs.
Lightly lubricate the piston skirt and piston rings.
Position each piston ring so that its gap is approximately 120° from the gap in the adjacent ring. This is to ensure that the three gaps are not aligned during reassembly.
Carefully locate the piston in the crankcase bore without scoring the aluminum skirt.
With the piston skirt in place, compress the piston rings into their respective grooves using a ring compression tool. Depending on the tool used, the Piston Rings can be compressed sequentially, in which case the Piston is fitted into the crankcase bore in three successive steps, or the Rings can be compressed together, in which case the complete Piston is fitted in one operation.
A certain amount of force is required to fit the piston into the bore, so care must be taken as any impact on the lips of the piston rings could cause irreparable damage and seriously affect compressor performance.
Lubricate the crankshaft and connecting rod bearing surfaces and threads.
Finally, reassemble the connecting rod cap over the crankshaft, making sure the cap is installed correctly. Tighten the connecting rod bolts to 13 to 16 Nm.
Rotate the crankshaft with the rod/piston assembly in place to ensure there are no tight spots.
Install a new sump plate gasket and reassemble the sump plate.
Install the valve plate-crankcase gasket and valve plate. Install new valve plate-cylinder head gasket and cylinder head.
Note: Any scratch in the crankcase bore or on any of the piston rings will cause a noticeable increase in compressor oil carryover.
5. Replacing the Rear Bearing Cover Seal
Required service parts/kits:
Seal Kit.
After removing and cleaning the bearing cover, make sure there are no burrs or sharp edges that could cut the seal during assembly.
Lubricate the seal groove in the bearing cover and install the new seal.
Lightly lubricate the journal (bearing cover to crankcase) and install the bearing cover.
Lubricate the 4 bolts and tighten them crosswise in one go to a torque of 22 to 24 Nm.
Make sure the crankshaft rotates freely and has a finite but minimal axial clearance.
6. Replacing the Sump Plate Gasket:
Requires service parts/kits:Gasket Kit
After removing the sump plate and gasket, carefully clean the mating surfaces of the crankcase and sump plate.
Place the new gasket on the cleaned surface of the sump plate (for a metal gasket, place the raised preformed side on the sump plate). Replace the sump plate and tighten the 4 bolts crosswise in one operation to a torque of 11 to 13 Nm.
7.Servicing the Energy Saving Systems (ESS): Required service parts/kits: Complete kit.
7.1. ESS in crankcase:
Remove the cylinder head, valve plate and inlet reed and associated ESS components from the top of the crankcase.
Remove the pin from the ESS piston.
Clean the top of the crankcase and check for burrs.
Check that the machined slot in the top of the crankcase is not damaged.
Remove the plug/cap holding the ESS piston in the crankcase and remove the piston and spring.
After lubricating the parts, reassemble the new spring and new ESS piston with anti-extrusion ring and O-ring into the crankcase.
Insert the dowel pin through the top of the crankcase into its hole in the ESS piston.
Manually actuate the piston to ensure that it fully returns to the off position under the load of the spring.
Mount the ESS Bell Crank by pushing it over the dowel pins and insert the sliding pin into the machined slot in the crankcase.
Position the inlet reed. It must fit within the profile of the new steel gasket. Make sure the inlet reed is not pinched under the steel gasket.
After reassembling these parts, manually actuate the ESS piston again to ensure that the inlet reed moves properly without jamming and that the assembly returns fully to the off position.
Depending on the version, install the plug/cap in the ESS piston bore in the crankcase:
- Bore: reinstall the cap with its O-ring in the bore and secure with the circlip.
- Threaded hole: Install the plug with its gasket in the unused hole and tighten to a torque of 50 to 55 Nm.
- Assemble the new valve plate-crankcase gasket, valve plate, new valve plate-cylinder head gasket, and cylinder head.
7.2. ESS in Cylinder Head
This operation can be performed without removing the cylinder head.
Remove the cover and the ESS piston, clean the bore machined in the cylinder head. Check the surface finish of the bore.
Lubricate all components and the cylinder head bore.
Install a new O-ring on the ESS piston and reassemble the piston in the cylinder head.
Position the new cover gasket and install the cover (do not block or cover the breather hole). Finally, secure the cover with the two bolts, tightening to a torque of 5.5 to 8.5 Nm.
