How much oil goes in a pressure washer pump? 54 examples


A pressure washer helps to clean the external areas and objects of your house easily. It saves a lot of time. Proper maintenance of the machine is required to enjoy its benefits for a long time. One of the key parts to check is the pump oil. The pump does not have an oil filter, so it needs to be replaced before it gets too dirty.

In general, most pressure washers use around 5 oz of pump oil. This means that a single bottle of pump oil is enough for an oil change. Most pumps use non-detergent oil, as the pump has no oil filter. Regularly check if the oil quality. Replace when needed. Some of the more budget-friendly pressure washers have a sealed pump, where oil can not be replaced.

How much oil goes in a pressure washer pump? 54 examples 1

Checking and replacing the pressure washer oil is something that many owners forget. They have more focus on the gas engine than the pump. This article will provide you information about the oil quantity that goes in a pressure washer pump. And I will also show how to check and replace the pump oil.

Oil type and quantity to be used in a pressure washer pump

The following table shows the different types of oils that can be used with different pressure washer pumps. It will also indicate the amount of oil that is required for the particular pump.

Pump Type
Oil Type
Oil Capacity
Many Karcher types
Non-detergent 15W 40 oil
4 oz
CAT 310 – 6105 crankcase
 
2.5 gallon
Many CAT types
Non-detergent 30W oil
Pour according to the sight glass
DAPC (Axial)
R & O 150 oil
8 oz
Mant Faip types
Synthetic 15W 50 oil
4 oz
Giant (HR series)
Synthetic 20W 50
4.5 oz
Giant (P316)
Synthetic 20W 50
17 oz
Giant (P303)
Synthetic 20W 50
14 oz
General
Non-detergent 30W
4 oz
Annovi Reverberi RKV
Non-detergent 30W
18.54 oz
Annovi Reverberi XMV
Non-detergent 30W
13.5
Annovi Reverberi XTV
Non-detergent 30W
9.92 oz
Pump Type
Oil Type
Oil Capacity
Annovi Reverberi XJV
Synthetic Shell Spyrex 75W 90 Synthetic 20W 40
5.25 oz
Axial Comet BXD2528G
non-detergent
2,2 oz (65 ml)
Axial AR RMV 25G30D
non-detergent
2,2 oz (65 ml)
Many Stihl pressure washers
non-detergent
3 oz
Craftsman Pressure Washer, Model 580.767300.
 
Less than 5 oz
GX series Crankcase Oil Capacity
Mobile 1 20W 50 Full Synthetic
4.1 fl. oz. (121 ml)
Cat 3FR Piston
ISO 68 high-pressure hydraulic pump oil
10 Ounces (0.30 Liters)
Cat 4FR Piston
ISO 68 high-pressure hydraulic pump oil
21 Ounces (0.62 Liters)
Cat 5FR Piston
ISO 68 high-pressure hydraulic pump oil
21 Ounces (0.62 Liters)
Cat 10FR Piston
ISO 68 high-pressure hydraulic pump oil
40 Ounces (1.18 Liters)
Cat 25FR Piston
ISO 68 high-pressure hydraulic pump oil
84 Ounces (2.48 Liters)
Cat 60FR Piston
ISO 68 high-pressure hydraulic pump oil
321.2 Ounces (9.50 Liters)
Pump Type
Oil Type
Oil Capacity
Cat 3FR Plunger
ISO 68 high-pressure hydraulic pump oil
15 Ounces (0.44 Liters)
Cat 5FR Plunger
ISO 68 high-pressure hydraulic pump oil
18 Ounces (0.53 Liters)
Cat 7FR, 8FR Plunger
ISO 68 high-pressure hydraulic pump oil
25 Ounces (0.74 Liters)
Cat 15FR, 18FR Plunger
ISO 68 high-pressure hydraulic pump oil
42.6 Ounces (1.26 Liters)
Cat 25FR, 28FR Plunger
ISO 68 high-pressure hydraulic pump oil
84 Ounces (2.48 Liters)
Cat 35FR, 38FR Plunger
ISO 68 high-pressure hydraulic pump oil
134.4 Ounces (3.97 Liters)
Cat 60FR, 68FR Plunger
ISO 68 high-pressure hydraulic pump oil
321.2 Ounces (9.50 Liters)
Cat 150FR  Plunger
Cat Pumps ISO 100 special formula premium grade
22.4 gallon (85.00 Liters)
Cat 1CX Plunger
ISO 68 high-pressure hydraulic pump oil
2.03 Ounces (0.06 Liters)
Pump Type
Oil Type
Oil Capacity
Cat 1DX Series
ISO 68 high-pressure hydraulic pump oil
8.5 Ounces (0.25 Liters)
Cat 2DX Series
ISO 68 high-pressure hydraulic pump oil
8.5 Ounces (0.25 Liters)
Cat 2SF, 2SFX Series
ISO 68 high-pressure hydraulic pump oil
10.1 Ounces (0.30 Liters)
Cat 2SFSEEL Series
ISO 68 high-pressure hydraulic pump oil
10.1 Ounces (0.30 Liters)
Cat 2SFQSEEL Series
ISO 68 high-pressure hydraulic pump oil
10.1 Ounces (0.30 Liters)
Cat 2SFP Series
ISO 68 high-pressure hydraulic pump oil
10.1 Ounces (0.30 Liters)
Cat 3DX, 3DNX Series
ISO 68 high-pressure hydraulic pump oil
8.5 Ounces (0.25 Liters)
Cat 3SP, 3SPX Series
ISO 68 high-pressure hydraulic pump oil
10.15 Ounces (0.30 Liters)
Cat 4DX, 4DNX Series
ISO 68 high-pressure hydraulic pump oil
8.5 Ounces (0.25 Liters)
Cat 4DX03ELR
ISO 68 high-pressure hydraulic pump oil
8.5 Ounces (0.25 Liters)
Pump Type
Oil Type
Oil Capacity
Cat 4HP Series
ISO 68 high-pressure hydraulic pump oil
22.6 Ounces (0.67 Liters)
Cat 4SF Series
ISO 68 high-pressure hydraulic pump oil
23.66 Ounces (0.70 Liters)
Cat 4SP, 4SPX Series
ISO 68 high-pressure hydraulic pump oil
10.1 Ounces (0.30 Liters)
Cat 5DX Series
ISO 68 high-pressure hydraulic pump oil
22.6 Ounces (0.67 Liters)
Cat 5SP Series
ISO 68 high-pressure hydraulic pump oil
13.5 Ounces (0.40 Liters)
Cat 6DX Series
ISO 68 high-pressure hydraulic pump oil
22.6 Ounces (0.67 Liters)
Cat 66DX Series
ISO 68 high-pressure hydraulic pump oil
18 Ounces (0.53 Liters)
Cat 67DX Series
ISO 68 high-pressure hydraulic pump oil
13.5 Ounces (0.40 Liters)
Cat 3CP Plunger
ISO 68 high-pressure hydraulic pump oil
12 Ounces (0.35 Liters)
Cat 5CP Plunger
ISO 68 high-pressure hydraulic pump oil
17 Ounces (0.50 Liters)
Cat 7CP Plunger
ISO 68 high-pressure hydraulic pump oil
38.9 Ounces (1.15 Liters)

How to check if the pressure washer pump oil is ok?

To check if the oil in the pressure washer pump is in good health, drain some of the oil. Or put a thin clean iron strip in the oil tank so that the oil sticks to the strip. Check the extracted oil, or oil sticking to the strip. Compare the color of the oil with the fresh oil. If the oil is milky or has any visible particles, it means that the oil is dirty and you need to change the oil. Very thin, less dense, or less viscous oil also indicate a need for an oil change. If the oil is not too thin or milky, you can continue to use it.

To check the quality of the oil in the pressure washer pump, you need to test the oil. For this purpose, you can either drain a small amount of oil in a container by removing the drain plug and secure the plug after getting a sample. Another way to check the oil is to put a thin strip inside the tank from the top so that it gets submerged in the oil. Take the strip out and check the oil with your fingers.

After getting a sample of the oil, check for the following:

● Check pump oil quality: Color

The color of the oil indicates its health. When the oil is used over a long time, it gets dark. If your pump oil is too dark or milky, replace it.

● Check pump oil quality: Thickness

Fresh oil is relatively thicker than used oil. Thickness can be taken as a measure to determine the health of the oil. Oil gets thinner when it gets hot. When the oil is used for a long period, it becomes very thin and flows like water. If the oil in your pump is very thin or has less viscosity, it means that the oil’s life span is over, and your pump needs an oil change. To make it easier, compare it with some fresh oil.

● Check pump oil quality: Visible particles

Another indicator for a dirty oil change is visible particles. A pressure washer pump does not have an oil filter, like a gas engine, that filters dirt. If you see any particles by rubbing the oil between your fingers, it shows that the oil is dirty and must be replaced.

How to check the pump oil level?

To check the pump oil level, you need to inspect the sight glass on the pump carefully. Locate the oil viewing glass with the help of the owner’s manual. Normally there is a sign or a mark at the viewing glass that helps to check the oil level. If the oil level is below the mark, you need to refill the oil.

Before checking the oil level, it is important to read the owner’s manual and work out the right oil levels for your pressure washer. Inspect the pump and locate the viewing glass. Generally, a small red dot in the center or two parallel lines indicates the right oil level. The dot represents that the oil in the pump should be up to that level. The parallel lines indicate that the right level of oil is in between the parallel lines.

Some pumps are pre-lubricated and sealed from the factory. Wobble and axial piston pumps fall in this category. These pumps require no oil maintenance for their whole life. If the owner’s manual does not say anything about oil change, I recommend first checking which pump type is used in your pressure washer. Use this to find information about how to check the oil level.

If your pump is pre-lubricated and sealed from the factory, you can not check the oil level or change the oil.

What to do if you do not know how much pump oil is needed?

If you do not know that how much pump oil is needed in your pump, check the owner’s manual. If you still can not find it, I recommend using 3/4th of the pump oil bottle while refilling the pump. Overfilling the oil tank may damage the pump and cause problems.

Generally, pressure washer pumps have a sight glass through which you can see the level of the oil inside the pump. The mark on the sight glass indicates the highest and lowest oil levels. The owner’s manual also mentions the type and oil quantity the pump needs.

If you have found the correct quantity of oil required for your pump, refill the oil from the pump oil bottle accordingly.

If you cannot locate the sight glass or if there is not any or there is no information about the oil quantity in the owner’s manual, slowly add oil. Give the oil time to flow to other parts of the pump. When you notice that you have added too much. Stop immediately. If you can, remove a little bit. You can use an oil suction tool for this. Let the pump work for a short while, and check again.

What type of oil should be used in a pressure washer pump?

In general, use the manufacturer-recommended oil. If you can not find it, use a 30W non-detergent oil for your pressure washer pump. Non-detergent oils contain additional additives and prevent residue build-up inside the pump. Pressure washer pumps do not have an oil filter, like gas engines, that cleans the oil.

The pressure washer companies often mention the type of oil in the owner’s manual. I always recommend using that type. Generally, manufacturers use their own branded oil product that is compatible with their pressure washers.

If you do not know the type of oil, you should use non-detergent oil in your pressure washer pump. Here are some tips that will help you to find the appropriate bottle of oil for your machine:

  1. ND: The oil bottle will have an “ND” designation. “ND” stands for Non-detergent.
  2. Non-detergent: The word “Non-detergent” might be written right on the bottle.
  3. Pump oil: Many brands write “Pump oil” on their bottles.

The main difference between pump oil and motor oil is their additives. Pump oil contains silicon compounds as a non-foaming agent. Motor oil contains magnesium sulfonate additives. Most pressure washer pumps use SAE 10W-30 or SAE 10W-40 oil. These designations, i.e., SAE 10W-30, show the viscosity of the oil. A liquid’s viscosity is its resistance to flow. High viscosity means high resistance and vice versa. The viscosity of the oil depends on temperature. The oil gets thinner as it gets hot.

At the same temperature, SAE-10 oil has less viscosity than SAE-40 oil. 10W 30 designates a multi-viscosity oil. It means that the oil performs like SAE 10 at low temperatures and SAE-40 at high temperatures. A multi-viscosity oil is not required in hot areas where it does not get cold enough, i.e., Florida.

How to change the oil in the pressure washer pump?

To change the oil in the pressure washer pump, first, remove the contaminants in the pump. Drain the old oil through the drain plug/bolt or using a suction gun. After draining it completely, secure the drain plug and refill the fresh oil in the pump.

Before changing the oil in the pressure washer pump, I always recommended checking the type of pump used in your pressure washer. Read the owner’s manual and check for any oil change instructions. Most budget-friendly electric pressure washer pumps are pre-lubricated and sealed at the factory. You can not change the oil in these pumps.

Most wobble and axial piston pumps do not require any additional maintenance throughout their life. These pumps are also sealed and have no access to change the pump oil or check the oil level.

Always read the owner’s manual carefully and check for any instructions regarding oil change. Suppose you do not find any information regarding oil change or pump maintenance. And no drain plug and fill cap means that your pump is pre-lubricated from the factory and does not require any oil change.

Changing the oil in the pressure washer pump is simple and is needed to keep your washer working well. Here are 3 simple steps to change the oil in the pressure washer pump.

Step 1: Remove the contaminants from the pump

The first step while changing the oil in the pump is to clear all the contaminants and pollutants in the pump. For this purpose, remove the wand and turn on the water supply. Start the engine as you normally do for a cleaning job. Produce a steady water spray for 2 to 3 minutes.

Step 2: Drain the old oil

Once you have removed the contaminants, the next step is to drain the old oil from the pump. You can extract the oil in the pump through the oil drain plug at the bottom. Or using an oil suction tool. If you have a gas-powered pressure washer, I recommend draining the gas first. Use a wrench to remove the drain plug. Allow the old oil to drain away in a container. Tilt the unit to drain the oil completely.

If you want to suction out the old oil, open the oil cap and insert the suction tool hose into the oil tank. The suction tool will take out the old oil. Always remember to secure the drain plug back to its place once the oil is drained completely.

Step 3: Refill the oil tank

After draining the old oil, refill the pump tank with fresh good quality oil. To know the type of oil and the right amount, check the owner’s manual. Open the oil cap and pour the new oil into the pump. Make sure to clean any oil drops or spillages after adding it.

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