1. Oil Pressure Testing

2. What Is Viscosity? Viscosity is a fluids resistance to flow.
Low viscosity – Thin oil
High viscosity – Thick oil

3. What Are The Functions Of Oil?
To cool
To lubricate
To seal
To dampen noise
It allows any worn particles to be returned to sump

4. Manual Checks To Be Carried Out Before Testing
Change the oil
Change the oil filter
Check the electrical connections on the oil pressure switch
It is very important that the oil and filter has been changed as this can affect your findings

5. Visual Checks To Be Carried Out Before Testing
Check around the sump and bell housing for any signs of leakage
Check front engine oil seal and pulley for any signs of leakage
Check oil filter and filter housing for any signs of leakage
Check fuel pump and engine components for tightness of bolts
Dip engine for oil
Make sure there is sufficient diesel in tank for starting

6. Pumps – What Is The Function Of A Pump?
The function of a pump is to generate flow in a system

7. Different Types Of Pumps
Piston type
Gear type – most commonly used in lubrication systems
Vane type
Roller type
Impeller type
Screw type

8. What Is Pump Displacement?
Pump displacement is the amount of fluid that a pump can move per stroke
Remember – Pressure results from a resistance to flow

9. Reasons For Abnormal Oil Pressure
Low oil level in the sump
Oil worn out/broken down
Leaks
Worn bearings
Relief valve not seated properly
Wrong grade of oil
Worn or perished seals
If the oil is too thin this will result in low oil pressure
If the oil is too thick this will result in high oil pressure

10. Film of oil between surfaces (shaft & bearing)
Oil feed
Bearing housing
Oil clearance
Bearing cap
Shell bearing
Film of oil between surfaces (shaft & bearing)

11. Procedures To Be Followed To Carry Out The Test
Remove oil pressure sender unit or the plug in the side of the engine block
Connect up the gauge
Start up the engine
Bring the engine up to normal running temperature/manufactures spec
Make a note of your findings
Compile a report

12. Manufacturers Specifications For The Lubrication System of Perkins Engine
Dip the engine for oil and check oil pressure evry day or every 8 hours
Replace oil and oil filter every 500 hours or 12 months
Only use good quality oil with a grade of 15W40 which is suitable for irelands temperatures and climate
According to the specifications of this engine the lubricating oil pressure at normal running temperature should be……
300kPa – 43lbf/in – 3.0kg/cm