Commercial Products
Hydraulicꢀ
Filtersꢀ
OEM Vs. Will-Fitꢀ
PART NO. 99051SL
Hydraulic Oil Filtersꢀ
1
Table of Contentsꢀ
Contamination .................................................................................................................2ꢀ
Filter comparison.............................................................................................................4ꢀ
Filter Ratings ...................................................................................................................4ꢀ
Use of This Manual
The information contained in this manual is supplementary to material found in other
sources, it is not a replacement for them. You should always consult Service Manuals,
Service Bulletins, Operator’s Manuals and Parts Books when necessary.
Service Manual Updates and Service Bulletins can be found on the internet at:
This Manual and the training program, which it supports, are both designed to help you
gain knowledge of the product, and to inform you of when and why to make the necessary
repairs. We have also included tips for performing those repairs.
This program is designed for you. Your input and participation is appreciated.
There is plenty of space in this manual for you to add your own notes and observations
TORO® Service Training
2
Hydraulic Oil Filtersꢀ
There are a lot of filter suppliers currently
manufacturing and selling filters for turf mowing
equipment. Through this program we will try to
explain the differences between "will-fit" filters and
genuine OEM filters.
Hydraulic Filters
OEM vs. Will Fit
Commercial Products
First lets look at hydraulic system failures. It isꢀ
believed that over 75% of all hydraulic systemꢀ
failures are caused by contamination.ꢀ
Contamination Causes Most Hydraulic
System Failures
These failures cost your business money throughꢀ
lost production, the unit is down.ꢀ
There is cost associated with replacing the failedꢀ
component.ꢀ
And if the oil is contaminated to the point that itꢀ
needs to be replaced early, that to will addꢀ
additional operating costs.ꢀ
• Over 75% of all Hydraulic System failures are a
direct result of contamination.
• Increased repair cost resulting from:
– Loss of Production (down time)
– Component Replacement Costs
– More Frequent Fluid Replacement (And Disposal)
All of these costs can be avoided by properlyꢀ
maintaining the equipment and keeping theꢀ
hydraulic oil clean.ꢀ
Contamination in the oil can inhibit the four mainꢀ
function of the oil.ꢀ
The oil is what actually transmits the energy (work)ꢀ
through the system.ꢀ
How Contamination Damages
Hydraulic Systems
The oil also has to lubricate the system.ꢀ
The heat in a hydraulic system is carried away andꢀ
dissipated by the oil. And the oil will seal up theꢀ
small clearances in the hydraulic system.ꢀ
• Contamination interferes with the four main
functions of the Hydraulic Fluid.
– To Act as an Energy Transmission Medium.
– To Lubricate Moving Parts.
– To Act as a Heat Transfer.
Contamination, be it water or dirt and metal, willꢀ
limit the oils ability to perform these functions.ꢀ
– To Seal Small Clearances.
TORO® Service Training
Hydraulic Oil Filtersꢀ
3
To give an example of some of the clearances in a
hydraulic system, If we look at the spool section of
an electric solenoid valve we can see that we will
have a clearance of .0004 to .0009. These tight
clearances will not accept contamination from the
oil with out experiencing a problem. It is therefore
important that the oil remains clean.
Electric Solenoid Valve
Spool To Bore Fit
Spool
Cage
.4369 / 4371 DIA.
.4375 / 4378 DIA.
.0004 MIN
Spool
in Cage
Clearance
.0009 MAX
Total
This is a comparison chart of come common
particles and their micron size.
Particulate Contamination
We can see that talcum powder is larger then we
will let through our normal hydraulic filter
Relative Sizes of Particles
Sizes of Familiar Objects
Substance
Micron
Inch
Grain of Table Salt
Human Hair
100
70
40
25
10
8
.0039
.0027
.00158
.001
Lower Limit of Visibility
White Blood Cells
Talcum Powder
Red Blood Cells
Bacteria (Average)
.00039
.0003
.000078
2
Here we see a solenoid valve spool that has been
scored by contamination.
Spool scored by
contamination
The marks on this spool can not be felt but they
are deep enough to cause problems with this
valve
TORO® Service Training
4
Hydraulic Oil Filtersꢀ
A typical quality hydraulic filter will have a rigid
cast base.
Toro Hydraulic Filters
• Filter Mounting Base
• Filter Element
– Steel Ends
The filter seal will be a rubber seal, which is
captive in the end of the filter.
– Rigid Cast Base
– Glued on Ends
– Proper Micron Rating
• Filter Element Seal
– Positive Rubber seal
Most Toro hydraulic filters will not have a bypass.
The bypass will allow unfiltered oil to flow past the
filter and back into the reservoir.
• Spring (coil)
– Captive in the Filter Element
– Resists heat related
Deformation
• Bypass Valve
– None for Hydraulic Filter
– Needs Complete Filtration
The filter element will have steel ends and it will be
fully glued on the ends.
The paper will also be the proper micron rating.
And the spring will usually be a coil spring. This
type of spring resists heat deformation
Some cheaper filters may have a stamped steel
base. This type of base can flex and leak.
“Will Fitter” Hydraulic Filters
• Filter Element
– Glued on Ends
•ꢀ Filter Mounting Base
– Stamped Steel
The filter element seal may be a non-captive seal.
Under higher pressure situations this type of seal
may leak.
– Uneven Gluing
– Can Flexꢀ
– Proper Micron Rating ?
•ꢀ Filter Element Seal
– Rubber seal
• Spring (Wafer)
The filter may have a bypass valve. This may be
because this filter is used in several applications,
some that require a bypass valve.
– Susceptible to heat related
Deformation
– Non-Captive
– Not a positive seal
•ꢀ Bypass Valve
– Some have Bypass valves
–ꢀ Allows unfiltered oil toꢀ
bypassꢀ
The filter element may or may not be glued on the
ends. The gluing may be uneven.
The micron rating of the filter element may not be
correct.
The filter may even be equipped with a wafer type
spring. This type spring can change tension
greatly under different temperatures
There are two ways to rate filters.
Micron ratings and Beta ratings.
Micron Rating vs Beta Rating
•
Rating of the Particle Size
Stopped by the Filter
•
•
Based on actual filter Efficiency.
With Micron ratings there are two sub ratings.
Rates the Filters Ability to
Capture Various Size Particles.
–
Nominal rating
Removes Approx. 80 % of
particles larger than rating.
Absolute
Removes all particles larger then
rating.
•
A nominal rating captures approximately 80% of
the particles larger then the rating.
–
•
–
–
Based on media hole size. Can
vary widely
A filter with an absolute rating removes all the
particles larger then the rating.
Not Based on Actual Filter
Performance
Micron ratings are based on the hole size of the
media. It is not based on the actual filter
performance.
Beta Ratings are based ion the actual filter
performance.
TORO® Service Training
Hydraulic Oil Filtersꢀ
5
The Beta rating will consists of two numbers.
The first number is the filtration ratio.
What Beta Numbers Mean
• First number
– Filtration Ratio
• Second Number
• Example of Beta Rating
– 2/2 = 50% of 2 Micron
particles
The second number is the particle size, in
microns.
– Particle Size
(Micron)
– 20/3 = 95% of 3
Micron particles
An example of a typical Beta Rating is:
– 75/5 = 98.6% of 5
Micron particles
2/2, That equals 50% of the 2 micron particles
20/3 That equals 95% of the 3 micron particles
75/5 That equals 98.6% of the 5 micron particles
This chart shows the filtration number and the
percentage of particles stopped.
Filtration Ratio
Filtration Ratio / Efficiency Table
1.01
1.1
1.0%
9.0%
1.5
33.3%
50.0%
80.0%
90.0%
95.0%
98.6%
99.0%
99.9%
2.0
5.0
10.0
20.0
75.0
100
1000
This slide shows the Beta rating for a Toro
Hydraulic filter.
Filter Comparison
We can see that this filter captures 98.6 percent of
the 5-micron particles.
• Toro Filter
– Beta Rating
– 2/2
• Carquest
Filter
– Beta Rating
– 25/4
– 20/3
The competitive filter is not even an absolute 20-
micron filter.
– 50/20
– 75/5
TORO® Service Training
6
Hydraulic Oil Filtersꢀ
These filters are not the same.
They may look the same and are manufactured by
the same company. However, the beta ratings are
not the same.
Are they the same
• Filter construction is
• Carquest filter catches:
– 96% of 4 micron particles
Identical
– Both filters made by
Donaldson Co.
– and only 98% of 20 micron
particles
These are not the same filters. Even though the
parts house substitution book says they are the
same.
– Toro filter catches 50 % of
2 micron particles, 95% of
3 micron particles and 98.6
percent of 5 micron
– Not even rated for 2 or 3
micron
particles
TORO® Service Training
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ª The Toro Company
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