Instructions for installing swivel into oilcap.
A 10mm hole must be drilled in the centre of the oil cap. Be careful doing this as it is easy to drill out of centre which will cause some problems later. The best way to do this is by drilling from the outside, not the inside of the cap. Drilling from the inside of the cap increases the chance of drilling the hole out of centre.
First mark out the centre of the cap and drill a small hole of about 1/8 inch. When this is done, increase the size of the hole to 10mm.
Remove the rubber sleeve from the fitting, leaving the metal washers in place. These washers are used to space the hose fitting above the oil cap in order to make it easier to connect the hose. Insert the swivel through the hole in the cap and re-install the rubber sleeve. It may be helpful in some cases to use several small spacing washers over the rubber to extend the nut down the shaft for easier tightening. This nut does not need to be tensioned very much - just enough to make the fitting firm in the cap. Now the cap can be replaced on the engine and the return hose connected.
Advantages of the swivel.
The Main advantage of the swivel fitting is in checking the oil flow through the filter. While the engine is running you can remove the cap to check oil flow. On engines which stall when the cap is removed. just use a spare cap for running.
Partial oil changes.
The swivel provides another extremely good function. Whenever you feel you would like to do a partial oil change, remove the cap and allow the engine to pump some oil into a container; then you can add some new oil. It is amazing just how little oil you need to add to make the oil in your engine look like new. The reason for this is because the oil in your engine is not dirty when you use a bypass filter. It may have taken on some colour from sub micron carbon and the small amount of oil added will show you just how clean it was.The oil you remove can be put into the fuel tank if it is a diesel engine. You recoup the cost of the oil and also dispose of it. It also provides fuel lubrication. Diesels can use quite a lot of oil in the fuel quite effectively. Many people are doing this. There are many reasons why you may need to remove oil. You may have overfilled your sump - just start the engine and pump it out again through the swivel. A swivel fitting is a must.