PRODUCT OVERVIEW

The Meritor 31373-00 is a genuine OEM inside tire

flex hose for the Meritor Tire Inflation System

(MTIS). Part number 31373-00 (also referenced as

3137300), this 17-inch long flex hose serves as the

critical air delivery conduit between the thru-tee

rotary union and the inside tire valve stem on

dual-wheel trailer axle configurations. It is also

used as the sole tire hose on super single tire

setups. Designed for use on wheels larger than

17.50 inches, the 31373-00 is a direct replacement

component for MTIS-equipped semi-trailers.

WHY THE MERITOR 31373-00 / KEY BENEFITS

GENUINE OEM MERITOR — This is a genuine Meritor

OEM component, not an aftermarket imitation. As the

original equipment manufacturer of the MTIS system,

Meritor engineers this hose to the exact

specifications required for proper system function,

including correct hose length, fitting geometry,

internal diameter, and pressure rating. Using

genuine Meritor hoses ensures proper airflow and

system integrity.

17-INCH LENGTH — INSIDE TIRE POSITION — The

31373-00 is the LONG flex hose in the MTIS wheel-end

assembly. Its 17-inch length is required because it

must reach from the thru-tee rotary union on the

axle, past the outside tire, and connect to the

inside tire valve stem. This is a longer routing

path than the outside tire hose (31363-00, which is

13.5 inches). The 31373-00 also serves as the tire

hose on super single tire configurations, where only

one hose per wheel position is needed.

STRAIGHT END FITTING — The inside tire hose features

a straight end fitting designed for direct routing

from the thru-tee to the inside tire valve position.

This differs from the outside tire hose (31363-00),

which uses a curved 180-degree fitting.

ABRASION-RESISTANT CONSTRUCTION — The 31373-00 is

constructed from abrasion-resistant synthetic

material with braided reinforcement that resists

road grit, debris, and the high-travel environment

between the axle and wheel end. The reinforced

construction prevents kinking during wheel

articulation, allowing the hose to flex naturally as

the wheel-end moves under varied loading conditions.

The outer jacket guards against abrasion, heat, and

chemical exposure, enabling long service life in

harsh operating environments.

TEMPERATURE TOLERANCE — The hose is rated for

operation from -40 degrees C to +100 degrees C

(-40 degrees F to +212 degrees F), supporting

dependable airflow in extreme cold, desert heat,

and everything in between.

UV RESISTANCE — The hose material is UV resistant,

prolonging service life for trailers stored outdoors

or operating in high-sun environments.

DESIGNED FOR WHEELS LARGER THAN 17.50 INCHES — The

17-inch length of the 31373-00 is specifically

engineered for inside tire routing on wheels larger

than 17.50 inches. This covers the vast majority of

standard semi-trailer wheel sizes (22.5-inch and

24.5-inch) used in North American commercial

trucking.

MTIS SYSTEM INTEGRITY — A failed or leaking flex

hose causes the MTIS system to lose its ability to

maintain tire pressure on that wheel position. This

leads to underinflation, increased tire wear,

reduced fuel economy, and elevated blowout risk.

Replacing a worn or damaged 31373-00 hose

immediately restores full MTIS function to that

wheel position.

SPECIFICATIONS

Part Number: 31373-00

Alternate Format: 3137300

Superseded Part Number: 12-M1373

Manufacturer: Meritor (now Cummins Drivetrain)

Description: MTIS Hose, Inside Tire, 17 inches

Type: Flex Hose (Inside Tire)

Position: Inside Tire — Long Flex Hose

  Also for use with Super Single Tires

Length: 17 inches

End Fitting: Straight End

Construction: Abrasion-Resistant Synthetic with

  Braided Reinforcement

For Wheel Size: Larger than 17.50 inches

Auxiliary Check Port: No

Temperature Range: -40°C to +100°C

  (-40°F to +212°F)

Marketing Group: Thru-Tees Hoses & Fittings

VMRS Code: 017-009-040

Weight: 0.18 lbs

Unit Pack: 1

Pallet Quantity: 1,920

UPC: 737238981398

Warranty: Cummins Drivetrain and Braking Systems

  Aftermarket Warranty (Bulletin SP16165)

Status: Active

Condition: New — Genuine OEM Meritor

Quantity: 1

PART NUMBER FAMILY / CROSS REFERENCE

CROSS REFERENCE — MERITOR 31373-00:

The following part numbers cross-reference to or

replace the Meritor 31373-00:

- 3137300

- 650-3137300

- MTR31373-00

- MER31373-00

- ME3137300

- TDA3137300

- 82353137300 / 8235-3137300

- RW31373-00

- 3137300RI / RI3137300

- ATI3137300

- HR3137300

- M3137300

- RO3137300

- TWD3137300

- P37000 / P37000TEC

- 177T73001

- 3092902

- EORB3137300

- MB3137300

- R93137300

- RB3137200

- RB3137300

Replaces Compatible with Dayton Parts Batco

  12M1373 / 12-M1373

Replaces Compatible with Globetech Mfg GT-4120,

  GT4120, GLBGT4120, GNGT4120

Replaces Compatible with Stemco 8100058, ST8100058

NOTE: Cross-reference listings indicate that the

31373-00 should be a suitable replacement for the

part numbers listed above. Always verify the

application before ordering.

MERITOR MTIS FLEX HOSE FAMILY:

- 31373-00 — Inside Tire Flex Hose, 17 inches,

  No Check Port, Wheels >17.50", Also Super Single

  (THIS LISTING)

- 31373-00-CP — Inside Tire Flex Hose, 17 inches,

  WITH Auxiliary Check Port, Wheels >17.50"

- 31363-00 — Outside Tire Flex Hose, 13.5 inches,

  No Check Port, Wheels >17.50"

- 31363-00-CP — Outside Tire Flex Hose, 13.5 inches,

  WITH Auxiliary Check Port, Wheels >17.50"

MERITOR MTIS THRU-TEE FAMILY:

- 31317-00 — Thru-Tee, Dual Tire, 4 inch Tube

  Length

- 31317-03 — Thru-Tee, Dual Tire, 3.5 inch Tube

  Length

- 31317-03-S — Thru-Tee, Super Single, 3.5 inch

  Tube Length

- 31317-04 — Thru-Tee, Dual Tire, ProPar Axle,

  5 inch Tube Length

- 31317-04-S — Thru-Tee, Super Single, 5 inch Tube

  Length

OTHER MERITOR MTIS COMPONENTS:

- 31314-21 — Stator and Filter

- Control Box (regulates tire psi)

- Self-Draining Air Filter

- ThermALERT Wheel-End Heat Sensing Technology

  (standard on newer MTIS systems)

FREQUENTLY BOUGHT TOGETHER:

When replacing MTIS wheel-end hoses on a dual-wheel

axle, both the inside and outside hoses are

typically replaced at the same time:

- 31373-00 — Inside Tire Flex Hose, 17"

  (THIS LISTING)

- 31363-00 — Outside Tire Flex Hose, 13.5"

- 31317-03 or 31317-04 — Thru-Tee (if worn or

  leaking)

APPLICATIONS AND COMPATIBILITY

The Meritor 31373-00 inside tire flex hose is

designed exclusively for the Meritor Tire Inflation

System (MTIS), which is installed on over 1 million

semi-trailers across North America.

WHAT IS MTIS?

The Meritor Tire Inflation System connects all tires

on the trailer to a controlled air supply. It

automatically maintains tires at the desired

pressure setting, even while the vehicle is in

motion. Pressurized air from the tractor air supply

travels through a self-draining filter, into a

control box where pressure is regulated to the

pre-set tire psi, through the hollow axle tube to

the rotary union (thru-tee), and then through the

flex hoses into the tires.

HOW THE 31373-00 FITS INTO THE SYSTEM:

The 31373-00 is the LONG flex hose that routes air

from the thru-tee to the INSIDE tire on a dual-wheel

configuration. It works in conjunction with the

31363-00 OUTSIDE tire flex hose (13.5 inches long),

which routes air to the outside tire. Both hoses

connect to the thru-tee rotary union. On super

single tire configurations, the 31373-00 is used

as the sole hose per wheel position.

COMPATIBLE TRAILER AXLE TYPES:

- Meritor TN axles with iron or aluminum hubs

- Meritor TP axles with ConMet iron or aluminum hubs

- Meritor TP axles with iron hubs (excluding ConMet)

- MTIS can be installed on all major trailer axle

  models in North America

- Available for new trailers and can be retrofitted

  on trailers already in service

WHEEL SIZE REQUIREMENT:

- For wheels LARGER than 17.50 inches (this covers

  the standard 22.5-inch and 24.5-inch semi-trailer

  wheels used in North American commercial trucking)

TIRE CONFIGURATION:

- Dual-wheel setups: Used as the INSIDE tire hose

  (paired with 31363-00 outside tire hose)

- Super single setups: Used as the sole tire hose

  per wheel position

BENEFITS OF MTIS:

- Extends tire life by 10%

- Improves fuel economy by an average of 1.4%

  (per FMCSA study)

- Reduces risk of tire blowouts

- Reduces frequency of manual tire pressure checks

- Virtually eliminates underinflation-related

  service calls

- ThermALERT technology alerts drivers to

  overheating wheel-ends

- Typical ROI within 1-2 years based on tire usage

INDUSTRIES AND FLEET TYPES:

- Over-the-road (OTR) long-haul trucking

- Regional and short-haul trucking

- Dry van trailers

- Refrigerated (reefer) trailers

- Flatbed trailers

- Tanker trailers

- Intermodal chassis

- Drop-deck and lowboy trailers

- Any MTIS-equipped semi-trailer

ABOUT MERITOR

Meritor, Inc. traces its roots to 1909 and was

formerly part of Rockwell International, which spun

off its automotive business as Meritor in 1997.

Headquartered in Troy, Michigan, Meritor is a

leading global supplier of axles, brakes, drivelines,

suspensions, and tire inflation systems for

commercial trucks, trailers, buses, coaches, and

military and off-highway vehicles. In August 2022,

Cummins Inc. completed the acquisition of Meritor

for $3.7 billion, making Meritor part of the

Cummins Drivetrain and Braking Systems division.

The Meritor Tire Inflation System (MTIS) is equipped

on more than 1 million trailers across North

America and has been reducing industry concerns

with tire pressure loss for more than 20 years.