Diaphragm Pump Oil: What You Need to Know


One of the most important factors in keeping your diaphragm sprayer pump running is maintaining the proper oil level. In addition to the correct amount, the type of oil used is important as well. In this post, you will find the type of oil and the amount needed for several different Udor, Hypro, and AR diaphragm pumps.

RELATED: Understanding the Different Types of Sprayer Pumps

What Type of Oil is Used in a Diaphragm Pump?

Most manufacturers have a special pump oil formulation that they offer specifically for their diaphragm pumps. These are usually SAE 30 or 40-weight non-detergent oils that will contain special additives that protect against the typical wear factors unique to diaphragm pumps. 

How Much Oil Goes in a Diaphragm Pump?

Below is a list of several common diaphragm pumps along with the type and quantity of oil they require. The amounts listed for oil capacity are approximate. In most diaphragm pumps you should fill a crankcase with oil until it shows about halfway up the sight glass. Site glass location will vary depending on the make and model of your pump. 

Hypro Diaphragm Pump Oil Type and Capacity

Pump ModelOil CapacityOil TypeOil Part Number to Order
9910-D25213 ozSAE 30W Non-DetergentHypro recommends the use of their oil in all of their diaphragm pumps:
Hypro Oil: 2160-0038

9910-D3018 ozSAE 30W Non-Detergent
9910-D30313 ozSAE 30W Non-Detergent
9910-D40313 ozSAE 30W Non-Detergent
9910-D5036 ozSAE 30W Non-Detergent
9910-D50318 ozSAE 30W Non-Detergent
9910-D81319 ozSAE 30W Non-Detergent
9910-D106424 ozSAE 30W Non-Detergent
9910-D126542 ozSAE 30W Non-Detergent
9910-D151577.5 ozSAE 30W Non-Detergent
9915-DP25224 ozSAE 30W Non-Detergent
9915-DP30224 ozSAE 30W Non-Detergent
9915-D30320 ozSAE 30W Non-Detergent
9915-D40320 ozSAE 30W Non-Detergent
9915-DP50317 ozSAE 30W Non-Detergent
9915-DP80324 ozSAE 30W Non-Detergent
9915-DP100324 ozSAE 30W Non-Detergent
9915-D106334 ozSAE 30W Non-Detergent
9915-D150442 ozSAE 30W Non-Detergent
9915-DP2505110 ozSAE 30W Non-Detergent

The Hypro 9910 series is extremely common, however, it was discontinued and replaced by the 9915 series. The same oil is used in both: Hypro Pump Oil 2160-0038.

AR pumps are nearly identical to the Hypro 9910 series. In fact, similar models can use the same repair parts. For example, a 9910-D30 and AR30 are the same and the diaphragms, valves, and o-rings are interchangeable.

AR Diaphragm Pump Oil Type and Capacity

Pump ModelOil CapacityOil TypeOil Part Number to Order
AR4513 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR7024 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR8013 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR11532 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR12028 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516
AR13532 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR14028 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516
AR16056 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR18556 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR21598 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516
AR25098 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516
AR25213 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516
AR28098 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516
AR410296 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR460296 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR500154 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR560154 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR3026 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR30315 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR4026 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR40315 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR5036 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR50322 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR81337 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR105359 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516
AR120359 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516
AR106430 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
AR160478 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
BHA13089 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
BHA15089 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64532D
BHA170119 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516
BHA200119 ozA/R Premium Diaphragm Pump Oil, SAE 30 Non-Detergent OilAR64516

Udor Pump Oil Type and Capacity

Pump ModelOil CapacityOil TypeOil Part Number to Buy
ZETA 4039 ozUdor SAE 40W Premium Pump Oil, Non-DetergentUdor recommends the use of their oil in all of their diaphragm pumps. Udor Oil: 15.5823

You can use any other 30 Weight non-detergent oil.
ZETA 8539 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 7020 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 10039 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 12040 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 14040 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 17044 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 20044 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 23090 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 26090 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 30090 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 350155 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
ZETA 400155 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
IOTA 187 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
IOTA 207 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
IOTA 257 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
KAPPA 74 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
KAPPA 154 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
KAPPA 184 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
KAPPA 2512 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
KAPPA 3220 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
KAPPA 4320 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
KAPPA 5523 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
DELTA 4020 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
DELTA 7523 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
DELTA 10040 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
DELTA 12569 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
DELTA 14054 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
DELTA 17067 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
OMEGA 14087 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
OMEGA 17091 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
BETA 13081 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
BETA 17091 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
BETA 200170 ozUdor SAE 40W Premium Pump Oil, Non-Detergent
BETA 240170 ozUdor SAE 40W Premium Pump Oil, Non-Detergent

Udor does provide an alternate oil option if you do not have Udor brand pump oil handy. You can use any SAE 30-weight, non-detergent oil.

When to Change Diaphragm Pump Oil?

Just like with a car diaphragm pumps have a crankcase, cylinders, and pistons that require lubrication. oil needs to be changed periodically to prolong the life of your pump. When a diaphragm pump is operating it creates heat and friction. Without new oil, the wear from friction and heat is more severe.

How often you change the oil varies slightly depending on the manufacturer of the diaphragm pump but in general, it is recommended that you change the oil every 500 working hours or three months whichever comes first.

The diaphragm in the pump is what separates the fluid that you are pumping and the oil in the crankcase. If the diaphragm is damaged or worn out then the oil and the chemical you are spraying will mix. This means that oil and your pump will get pumped down along with your spray solution. It also means that my chemical and your spray solution will be present inside the crankcase. This can cause damage to the cylinders, pistons, connecting rods, etc.

If you notice the oil in the sight glass is cloudy or milky and color when it is time to change diaphragms and change the oil. Whatever you change diaphragms you should flush out the crankcase with fresh water and refill it with new oil. 

New Pump Oil

Some pump oil manufacturers add a colored dye to their oil. This may cause the oil to look darker and not like new oil. Example: Hypro pump oil has a green dye added to it.

Tips on How to Change Diaphragm Pump Oil

Drain the pump completely of the remaining water/spray mixture and oil. Remove the heads to replace the diaphragms. Flush out the crankcase. When you fill the pump with oil, rotate the pump to get all the air pockets out of the pump. The oil level in the sight glass will go down as you turn the pump. Add oil as you turn the pump until it is at the proper level and no more air bubbles are coming out.

More Information on Diaphragm Pumps

If you are new to diaphragm pumps you can find resources for building sprayers and troubleshooting diaphragm sprayer pumps here:

Shane Blomendahl

I have more than a decade of experience using, building, studying, and testing sprayers in several applications. With the knowledge I have gained I want to provide straight forward and detailed answers for DIY homeowners, farmers, and commercial turf and tree care pros.

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