• Company Name: Continental Tyre AS Malaysia Sdn. Bhd.
  • Location: No.1,Jalan Tunku Abdul Rahman, Mergong, 05150 ALOR SETAR, KEDAH DA
  • Product Installed: MFS-2XSDU/9788 + MM5/KM
  • Industry: Rubber
  • Process Type: Tyre


  • To evaluate the effectiveness of KLEENOIL depth filter in improving the cleanliness level of a sample of used hydraulic oils marked OIL PIT intended for waste disposal so that the purified used oil can now be used as a base oil for re-refined lubricants.
  • • Also to evaluate how the same KLEENOIL unit is able to improve the cleanliness levels of hydraulic oils in the hydraulic power packs to improve performance and extend oil change intervals.


  • With 2 filter units, magnetic filter and particle counter
  • Model: MFS-2XSDU/9788 + MM5/KM.
  • Flow rate: 600 litres per hour
  • Suitable for tank size: up to 4000 litres
  • Dimension: 700 mm L x 600 mm W x 1100 mm H
  • Particulate removal capacity: ~ 3 kg per cartridge
  • Moisture removal capacity: 1.2 litres per cartridge


  • Oil samples for filtration: Each in 20 litres pails
  • Oil Names: PETRONAS Hydraulic 46 (HYD 3) & CASTROL Hyspin HLP AF 46 (LINE D)
  • Hydraulic Power Packs Quantity: Total ~ 20 units
  • Hydraulic Power Pack oil reservoir capacity: Each 200-litre
  • HYD 3 sample was from Hydraulic Press No. 3 with an oil leakage problem that frequently top up with
  • PETRONAS Hydraulic 46 is necessary. Though operated for 2 weeks duration, the topping-up oil
  • resulted in the sample appearing to be like new.
  • LINE D sample was from Hydraulic Press Line D. The oil has been used for 2 weeks with no
  • leakage and oil topping up.
  • Oil Pit quantity & dimensions: 2 nos, 10 ft (Length) x 5 ft (Depth), 5 ft (Width)
  • OIL PIT sample was taken from one of the two concrete-used oil pits that contain not just hydraulic
  • oils but other types of waste oils and water. The sample was taken from the top of the Oil Pit with minimum
  • contamination of moisture. No pre-treatment with KLEENOIL LVDH (Low Vacuum Dehydration)
  • unit is necessary for this sample (only). Strongly recommend to pre-treat with KLEENOIL LVDH if
  • used oil contains moisture that would unnecessarily deplete the filtration capacity of the KLEENOIL
  • Depth Filters.


  • Dates carried out : 11th January 2023
  • Hose connections: suction hose and delivery hose to a pail containing the oil to be filtered

  • HYD3

  • Test duration: 2 hours duration (14.30 hrs to 16.49 hrs)
  • NAS 1638 cleanliness reading (Before filtration): 8
  • NAS 1638 cleanliness reading (After filtration): 5
  • Appearance (Before filtration): Light yellow, very lightly cloudy
  • Appearance (After filtration): Light yellow, clear


– Test duration: 1 hours 19 mins (09.30 hrs to 10.49 hrs)

– NAS 1638 cleanliness reading (Before filtration): 13

– NAS 1638 cleanliness reading (After filtration): 5

– Appearance (Before filtration): Light yellow, cloudy

– Appearance (After filtration): Light yellow, clear


– Test duration: 2 hours 33 mins (11.00 hrs to 13.33 hrs)

– NAS 1638 cleanliness reading (Before filtration): 13

– NAS 1638 cleanliness reading (After filtration): 6

– Appearance (Before filtration): Brownish, cloudy

– Appearance (After filtration): Light brown



  • The demonstrations were carried out at the premises of Tremack Holdings Sdn Bhd in Kota Kemuning with 3 samples of ~ 20 litres each using hydraulic oils provided by Continental Tyre AS Malaysia Sdn. Bhd, Alor Setar.
  • The oil samples were filtered for only short durations from 1 hour 19 minutes for the least contaminated to 2 hours 33 minutes for the most contaminated one. The cleanliness levels of these used oils improved vastly from the initial NAS 1638 level 13 to level 5, depending on the initial cleanliness and duration of filtration. These were shown on the built-in NAS meter. (Please refer to the attached Guide-to-Contamination-Standards.pdf for definition and explanations).

HYD 3 Sample

  • HYD 3 sample of Hydraulic Press No: 3 is PETRONAS Hydraulic 46 non-zinc free anti-wear hydraulic oil that the system is facing leakage problem that requires frequent top ups and thus the sample has the least contamination level of NAS 1638 Level 8. The typical cleanliness value of new hydraulic oil is NAS 1638 Level 9. Within 1 hour 19 minutes, the cleanliness level become NAS Level 5.
  • At NAS 1638 Level 5, KLEENOIL filtered hydraulic oil is cleaner than new hydraulic oil! Minimal change in oil appearance is expected. The same goes for the KLEENOIL Oil Patch Test. Even though the cleanliness level change is only 3, such improvement is beneficial to prolonging the lifespan of hydraulic components.

LINE D Sample

  • LINE D sample of Hydraulic Press Line D is CASTROL Hyspin HLP-AF 46 zinc-free anti-wear hydraulic oil. Unlike Hydraulic Press No: 3, the system is not facing leakage problems that no topping up was carried out during the 2 weeks the oil has operated.
  • Considering the relatively short operating hours of sample LINE D, the contamination level achieved was NAS 1638 Level 13. At this level, so much damage would have been done by the particulates if not removed by depth filters such as KLEENOIL. Within 2 hours, the oil achieved NAS 1638 Level 5, far cleaner that is new hydraulic oils!
  • Visual inspection of LINE D sample reviewed that the oil has not oxidised (changed to darker colour) but contaminated with particulates that can easily be removed by KLEENOIL. Thus the filtered oil is not much different from new oil. KLEENOIL Oil Patch Test result further confirmed this as there is no change in before and after appearances. Oxidation by-products darkens the test patches but not so much the particulates.
  • KLEENOIL Depth Filter removes, in addition to particulates, 1.2 litres of free and emulsified water in oils per cartridge. It will be very useful in the event of presence of water in hydraulic oils.

OIL PIT Sample

  • OIL PIT sample, as the name sounds, is expected to be a highly contaminated oil that is not fit for use as base oil for re-refined lubricants. KLEENOIL Depth Filter managed to remove most of the contaminants, particulates but not so much the colour as these are from oil soluble contaminants. The filtered oil can now be sold as re-refining base oil instead of disposed off as waste oil. During the rerefining process, bleaching earth is able to reduce these coloured contaminants.
  • OIL PIT sample was brownish, cloudy appearance but changed to light brown clear appearance. The NAS 1638 Level dropped from 13 to only 6. Had the filtration process been prolonged further, NAS 1638 Level 5 is achievable but this defeat the purpose as the oil is intended not for reuse as hydraulic oil but as re-refining base oil.
  • The KLEENOIL Oil Patch Test shows a high level of contamination in the “Before” sample but much lower level of contamination in the form of lighter colour in the “After” sample.
  • The original intended application of KLEENOIL Depth Filter is to re-refine the waste oil from the waste oil pit into cleaner oil that can be used as base oil for re-refined lubricants manufacturing as part of the environmental conscious campaign by the Continental Group. The same unit can be used to improve the performance and prolong the lifespan of hydraulic oils which in doing so reduce the waste disposal further contributing to the environmental conscious campaign.
  • OIL PIT sample was sampled from the top of the waste oil pit that the water at the bottom of the pit was avoided. In view the likelihood of waste oil from the pit with high moisture/water content be filtered by KLEENOIL Depth Filter thereby unnecessary loading the filter cartridges, it is best that these waste oil be pre-treated by KLEENOIL LVDH (Low Vacuum Dehydration) unit that does not use any consumables such as cartridges.
  • With KLEENOIL Depth Filter coupled with KLEENOIL LVDH, the task of converting the waste oil to re-refined base oil becomes feasible and economical. Coupled with the performance improvement and prolonged oil change intervals of the Hydraulic Press Lines, With large dirty holding capacity @~3kg per cartridge, KLEENOIL Depth Filter and LVDH are very cost effective investments!