Hydro-Gear Hydraulic Pump Guide: How to Find the Right PG, PK or PR Series Pump

When a zero-turn mower suddenly feels weak on one side, becomes difficult to control, or no longer drives the way it should, the hydraulic system is an obvious place to look. But finding a replacement Hydro-Gear hydraulic pump isn't as simple as buying another pump that looks the same.

The safest starting point is the full Hydro-Gear model number stamped or printed on the existing pump, followed by the mower manufacturer's OEM part number and equipment model. That's important because two Hydro-Gear pumps can look nearly identical while having different displacement, rotation, configuration or equipment compatibility. Hydro-Gear itself advises against substituting a different hydrostatic unit simply because its physical dimensions appear similar.

For owners and service professionals working on commercial zero-turn mowers, Carroll Stream carries genuine Hydro-Gear replacement pumps for applications from manufacturers including SCAG, Toro and Exmark, with several PG, PK and PR Series configurations available.

How Do I Find the Correct Hydro-Gear Hydraulic Pump?

Match these four things before ordering:

1. The complete Hydro-Gear model number on the existing pump.
2. The OEM mower manufacturer's part number.
3. Your mower's exact model and, when applicable, serial number.
4. The pump's position or configuration, including left versus right when the mower uses different pumps on each side.

Do not choose a pump based only on its appearance or series name. That simple verification can save a great deal of downtime.

What Does a Hydro-Gear Hydraulic Pump Do?

On a hydrostatic mower drivetrain, the pump turns mechanical input from the engine into hydraulic flow. That hydraulic power is sent to a hydraulic motor, allowing the machine's speed and direction to change without a conventional geared transmission.

Hydro-Gear describes a hydrostatic transmission as a system using a variable-displacement, bidirectional axial-piston pump and hydraulic motor. Changing the pump's swash-plate angle changes hydraulic flow, which in turn changes vehicle speed and direction. This is one of the reasons zero-turn mowers can deliver such precise steering.

Understanding Hydro-Gear PG, PK and PR Series Pumps

One useful clue is found at the beginning of the Hydro-Gear model number.
Hydro-Gear's official cross-reference identifies several P Series pump families by displacement:

Hydro-Gear Series	Pump Displacement	Also Known As
PG Series	10cc	BDP-10A
PK Series	12cc	—
PR Series	16cc	BDP-16A

But there's an important distinction:
Knowing the series does not automatically tell you which pump will fit your mower.

A PG-1GCC-DY1X-XXXX and a PG-1GNP-DY1X-XXXX are both PG Series pumps, for example, but they have different OEM cross-references and applications. Think of PG, PK or PR as the beginning of the identification process.

Hydro-Gear PG Series: A Common 10cc Commercial Hydraulic Pump

The Hydro-Gear PG Series is identified by Hydro-Gear as a 10cc pump family and is also associated with the BDP-10A designation. Several PG configurations available through Carroll Stream illustrate why the complete model number matters.

Hydro-Gear PG-1GCC-DY1X-XXXX

The PG-1GCC-DY1X-XXXX is used in applications that include select SCAG Tiger, Tiger Cat, Tiger Cub and Wildcat mowers as well as compatible Dixon, Husqvarna, Gravely and Howard Price equipment. Cross-referenced part numbers include Hydro-Gear BDP-10A-419, SCAG 482644, Gravely 21553100 and several Dixon/Husqvarna numbers.

Hydro-Gear PG-AGNP-DY1X-XXXX

Another PG Series configuration, the PG-AGNP-DY1X-XXXX, is designed for select Toro applications, including Toro Z Master Z500 and Z528 equipment. Carroll Stream lists it as a replacement for Toro 110-4150.

Hydro-Gear PG-1GNP-DY1X-XXXX

The PG-1GNP-DY1X-XXXX provides another example of how specific a hydraulic-pump match can become. Carroll Stream lists this configuration for select Toro and Exmark equipment, including Exmark Lazer Z HP and Lazer Z CT applications. It crosses with Hydro-Gear BDP-10A-414, Toro 103-1942 and Exmark 103-1942.

BDP-10A-414 replacement, Toro 103-1942 pump, Exmark 103-1942 hydraulic pump
Three PG Series pumps. Three different sets of applications.
That's why the numbers after "PG" are so important.

Hydro-Gear PK Series: 12cc Pump Options for Commercial Zero-Turn Mowers

Hydro-Gear identifies the PK Series as a 12cc pump family. One option available through Carroll Stream is the Hydro-Gear PK-BGAB-EY1X-XXXX. This genuine Hydro-Gear hydraulic pump is used on select Toro and Exmark zero-turn mowers. Listed applications include Toro Z500 Z Master machines from certain model years and configurations as well as Exmark Lazer series equipment.

It crosses with part numbers including:

• Toro 116-2444
• Toro 103-7262
• Exmark 103-7262
• Exmark 116-2444
• Hydro-Gear PJ-BGAB-EY1X-XXXX

Hydro-Gear PR Series: Left and Right Pumps for SCAG Turf Tiger Applications

The Hydro-Gear PR Series is particularly interesting for owners of certain SCAG Turf Tiger mowers because some applications use distinct left- and right-side pump configurations. Hydro-Gear identifies PR as its 16cc pump family, also associated with the BDP-16A designation. Two examples demonstrate why "left or right?" can be just as important as the model number itself.

Hydro-Gear PR-2JBC-GY1E-XXXX — Left Hydraulic Pump

The PR-2JBC-GY1E-XXXX is configured as a left-side hydraulic pump for compatible SCAG Turf Tiger applications. Carroll Stream lists this pump as a replacement for SCAG 483100.

Hydro-Gear PR-2HBC-GY1E-XXXX — Right Hydraulic Pump

The corresponding PR-2HBC-GY1E-XXXX is configured as a right-side hydraulic pump and is listed as replacing SCAG 483101.

Can I Use the Left Hydro-Gear Pump on the Right Side?

No—not simply because the pumps look alike.
If your mower specifies separate left- and right-side pump numbers, match the replacement to the correct side. For these SCAG applications:

• PR-2JBC-GY1E-XXXX = Left
• PR-2HBC-GY1E-XXXX = Right

Always verify the number on the existing pump and your equipment documentation before purchasing.

How Do I Know If My Zero-Turn Mower's Hydraulic Pump Is Bad?

A weak or poorly driving mower does not automatically mean the hydraulic pump has failed. Possible symptoms that warrant investigation can include:

• One side driving differently than the other
• Reduced drive power
• Poor response when steering
• Abnormal hydraulic noise
• Hydraulic leakage
• Difficulty maintaining expected ground speed

However, Hydro-Gear notes that apparent loss of power can also have other causes, including loose drive belts, linkage adjustment problems or low engine speed. That makes proper diagnosis important before replacing an expensive hydraulic component.

Should I Replace Both Hydraulic Pumps at the Same Time?

Not necessarily.
Many zero-turn mowers use two separate hydraulic pumps, but that does not mean both automatically require replacement when one fails. The correct decision depends on the condition of the entire hydraulic system, the specific mower and the reason for the original failure.

What is especially important is determining why a pump failed. Contamination elsewhere in the hydraulic system can damage a replacement pump if the root cause isn't addressed. Carroll Stream's product guidance recommends steps such as flushing hydraulic tanks and lines, replacing the hydraulic oil filter and inspecting the wheel motor when installing certain replacement pumps. Always follow the service procedures specified for your particular Hydro-Gear product and mower.

What Should I Check Before Buying a Replacement Hydro-Gear Pump?

Before clicking "Add to Cart," take a few minutes to verify the following.

1. Find the Hydro-Gear identification label

Hydro-Gear products include model and serial-number identification that can be used when looking for parts or service information.

2. Write down the entire model number

Don't stop at "PG," "PK" or "PR."
For example:
PG-1GNP-DY1X-XXXX

is much more useful than:
PG Series

3. Check your mower's OEM part number

A Toro, SCAG or Exmark part number can provide another strong confirmation.

4. Verify left versus right

This is especially important on equipment with side-specific pump configurations.

5. Check mower model and serial number

Some pump applications vary according to mower model year or serial-number range.

6. Don't assume a similar-looking pump is interchangeable

Hydro-Gear specifically warns that products with similar external dimensions can contain substantial internal differences.

PG vs. PK vs. PR: Which Hydro-Gear Pump Do I Need?

Here is the simplest answer:
You need the Hydro-Gear pump specified for your exact mower—not simply the series with the displacement you prefer.

The PG, PK and PR designations help identify the pump family:

• PG = 10cc / BDP-10A
• PK = 12cc
• PR = 16cc / BDP-16A

But displacement alone does not establish compatibility. The complete model number, OEM cross-reference, mower model, serial range and pump configuration should all be checked.

Why Choose a Genuine Hydro-Gear Replacement Pump?

When you're repairing a hard-working zero-turn mower, hydraulic performance affects much more than whether the machine moves. It affects speed control, steering response and your ability to maneuver accurately.

Using the correct genuine Hydro-Gear replacement also removes some of the guesswork involved with attempting to substitute a pump of unknown internal configuration. For commercial operators, where equipment downtime can directly affect the day's workload, getting the correct pump the first time matters.

Find Hydro-Gear Hydraulic Pumps at Carroll Stream

Whether you're replacing a SCAG Turf Tiger hydraulic pump, repairing a Toro Z Master, servicing an Exmark Lazer or trying to cross-reference an older BDP-series pump, start with the identification number on your existing Hydro-Gear unit. Carroll Stream carries multiple genuine Hydro-Gear hydraulic pump configurations, including:

• Hydro-Gear PG-1GCC-DY1X-XXXX PG Series
• Hydro-Gear PG-AGNP-DY1X-XXXX PG Series
• Hydro-Gear PG-1GNP-DY1X-XXXX PG Series
• Hydro-Gear PK-BGAB-EY1X-XXXX PK Series
• Hydro-Gear PR-2JBC-GY1E-XXXX Left PR Series
• Hydro-Gear PR-2HBC-GY1E-XXXX Right PR Series

The best replacement isn't the pump that looks closest.
It's the pump that matches your machine.

Verify the number, check the OEM cross-reference, confirm the application—and get your mower moving the way it was designed to.

Frequently Asked Questions About Hydro-Gear Hydraulic Pumps

What is a Hydro-Gear PG Series pump?

The Hydro-Gear PG Series is a 10cc hydraulic pump family also identified as the BDP-10A family in Hydro-Gear's cross-reference documentation.

What is a Hydro-Gear PK Series pump?

Hydro-Gear identifies the PK Series as a 12cc hydraulic pump family. The exact PK model number still needs to match the equipment application.

What is a Hydro-Gear PR Series pump?

Hydro-Gear identifies PR as a 16cc hydraulic pump family, also associated with BDP-16A.

Are Hydro-Gear PG, PK and PR pumps interchangeable?

No. Similar physical size or appearance does not make Hydro-Gear pumps interchangeable. Hydro-Gear recommends using the hydrostatic unit specified by the original equipment manufacturer.

Where do I find my Hydro-Gear pump model number?

Look for the identification label attached to the Hydro-Gear product. Use the complete model number, not only the first two letters of the series.

What's the difference between a left and right Hydro-Gear hydraulic pump?

Certain equipment uses different configurations for each side. For the SCAG applications discussed above, PR-2JBC-GY1E-XXXX is the left-side pump and PR-2HBC-GY1E-XXXX is the right-side pump.

Can a weak zero-turn mower mean something other than a bad hydraulic pump?

Yes. Hydro-Gear notes that power loss can have multiple causes, including drive-belt, linkage and engine-speed issues. Diagnose the system before assuming the hydraulic pump needs replacement.

Should I flush the hydraulic system when replacing a pump?

Contamination can damage hydraulic components. For several of these replacement pumps, Carroll Stream recommends flushing the hydraulic tank and lines, replacing the filter and checking related components such as the wheel motor. Follow the manufacturer's service manual for your exact equipment.