The Auto Cap
The Cap is a straightforward component but if the breather hole gets blocked with dirt or oil then no air can get into the oiler unit.
Simply put, no air in, no oil out - the oiler will stop working.
To rectify this, remove the cap from the oiler and wash it out in clean soapy water - don't use harsh chemicals or solvents as these chemically attack the plastic and cause the cap to swell or shrink, meaning it wont fit properly and may crack the acrylic tube (see Fig 3. below)
Synthetic/semi-synthetic oils can also effect the cap making it swell increasing its diameter, if this increased diameter cap is forced into the acrylic reservoir tube it will result in "J" shaped crack - (see Fig 3. below)
If you look carefully you will see there is a small 1.5mm diameter hole in the rim of the cap - this must be clear for the unit to function properly, use a paper clip to poke out any dirt when you are washing the cap out.
Dry thoroughly and replace on the oiler, making sure that there isn't any water or soap blocking the breather hole.
Fig 1. Cap showing breather hole outside.
Fig 2. Cap showing breather hole inside.
If the Oiler is over filled the unit's operation will be damped by the oil and its function will be severely compromised. Additionally oil may be forced into the breather hole cutting off the ingress of air and completely disabling the unit until such time as the oil level is lowered and the Cap is cleaned out.
If the oil level is too high, then use a small pipette or similar to remove oil until the level is at or below the "Max Oil" level as indicated by the label on the rear of the oiler reservoir. Do not touch, press or pull the steel weight during this operation.
Fig 3. Crack caused by forcing an oversized cap into the reservoir tube