- +Five chrome trumpets on one flange is the largest, most locomotive-looking cluster United Pacific sells
- +12V heavy-duty solenoid valve comes factory-fitted, so onboard-air trucks only need line and a switched circuit
- +United Pacific horns have a consistent owner-forum reputation for authentic train-horn tone
- +Widely stocked across truck-parts dealers at a fairly tight $400-$424 spread
- +Chrome finish suits show trucks and chrome-heavy big rigs without repainting
- −155 dB rating carries a ±10 dB tolerance and no disclosed test distance
- −No published operating or maximum PSI, unlike the brand's 150 PSI-rated 46129 and 46130
- −Horn only: no compressor, tank, line, relay or wiring, and no kit version offered
- −Dealers disagree on brass versus plain chrome construction; manufacturer does not say
- −Six-month warranty is short next to one-year terms from kit brands
- −Roughly double the price of the four-trumpet 46130 for one extra trumpet, with no customer reviews at any dealer
Methodology
This review aggregates publicly available information from manufacturer specifications, retailer listings, and verified user reviews. We do not perform hands-on testing. United Pacific’s commercial-truck web store sits behind bot protection, so our primary document is the factory spec sheet for part 46131, a printout of United Pacific’s own product page that Vehicle Safety Supply hosts as a PDF. We cross-checked it against the Vehicle Safety Supply, Fitzgerald Truck Parts, Truck Town, TruckAC and Chrome Country listings, a YouTube sound demo, replacement-part listings, and Train Horn Forums owner threads about United Pacific horns. Last reviewed: September 14, 2026.
Quick verdict
The United Pacific 46131 is the biggest horn in United Pacific’s chrome train-horn family: five chrome trumpets on one base, with the 12-volt solenoid already fitted, at roughly $400 to $424 from truck-parts dealers. It earns a 3.3/5 from us. The appeal is obvious. A five-trumpet chrome cluster is the full locomotive look for a show truck or a big rig, and United Pacific’s triples and quads have a reputation in owner communities for sounding like real train horns rather than generic truck air horns. What holds the score down is the paperwork: the 155 dB claim carries a ±10 dB tolerance and no test distance, there is no published PSI rating, no chord frequencies, dealer listings disagree on the trumpet material, and the warranty is six months. At roughly double the price of United Pacific’s own four-trumpet 46130, you pay a lot for the fifth bell. This is our editorial judgment from aggregated data, not an in-house test.
What it is
The 46131 is a horn-only product, not a kit. United Pacific’s spec sheet describes it in one line: “Chrome heavy duty 5 trumpet train horn, super loud.” The product photo on that sheet shows five chrome trumpets of mixed lengths stacked in a cluster on a single round mounting flange, with the electric solenoid valve fitted at the base. United Pacific Industries is a Long Beach, California parts maker whose commercial-truck division sells chrome accessories for semis, and the marketing copy is aimed squarely at that crowd: the spec sheet talks about trucking safety and installing a horn “that is much louder than a regular horn.”
That framing tells you who this is for. The 46131 assumes you already have onboard air, which means a Class 8 truck with an air brake system, or a pickup or show vehicle that already runs a compressor and tank. It ships with no compressor, no tank, no air line and no wiring, and none of the dealer listings we read offer a bundled air system for this part.
Within United Pacific’s line, the 46131 sits above the 3-trumpet 46129, the 4-trumpet 46130 and the 4-trumpet 46152 Competition Series, all of which we have reviewed. It is the only five-trumpet model we have seen listed in United Pacific’s range, and it costs roughly twice as much as any of them. The brand also lists a 5-trumpet chrome train horn, model 46131, on its truck-division site at truck.upauto.com, which is the listing our spec sheet was printed from.
Specifications
| Spec | Value |
|---|---|
| Model | United Pacific 46131 (UPC 710270461318) |
| Trumpets | 5, chrome-plated, single-flange cluster |
| Advertised sound output | 155 dB ±10 dB (test distance not disclosed) |
| Operating / max pressure | Not published for this model (sister models are rated 150 PSI max) |
| Valve | 12V heavy-duty electric solenoid, included |
| Construction | Chrome-plated; two dealers list brass, United Pacific’s sheet does not state the base metal |
| Horn dimensions (dealer-listed) | 17” L × 17” W × 15” H |
| Package dimensions (spec sheet) | 20.9” L × 17.6” W × 18.5” H |
| Package weight | 24.5 lb |
| Chord frequencies | Not disclosed |
| Air supply | Not included; external onboard air required |
| Warranty | 6 months |
| Street price | $399.99 to $423.55 |
Three notes on that table. First, the dimensions that conflict across the web are not really in conflict: the 17 × 17 × 15 inch figure appears on the Chrome Country listing as the horn’s own size, while the 20.9 × 17.6 × 18.5 inch figure on the spec sheet is explicitly labeled “Package Dimension.” Plan mounting space around the smaller number and shipping around the larger one. Second, the 24.5 lb figure is also a package weight, so the bare horn is somewhat lighter, though five metal trumpets on a flange are never going to be light. Third, the material question is unresolved. Fitzgerald Truck Parts and TruckAC describe the horn as “brass with chrome plating,” but Vehicle Safety Supply, Truck Town and Chrome Country say only “chrome,” and United Pacific’s own sheet is silent. Dealers describe United Pacific’s four-trumpet 46152 as zinc alloy, so we treat brass as a dealer claim, not a confirmed fact, until the manufacturer says otherwise.
- Trumpets
- 5, chrome
- Rated output
- 155 dB ±10 dB, distance not stated
- Valve
- 12V solenoid, included
- Air
- Not included
- Warranty
- 6 months
What’s in the box
Every dealer listing and the spec sheet agree on the same short list. United Pacific sells the 46131 as a single unit.
- Five-trumpet chrome train horn assembly on a single mounting flange
- 12-volt heavy-duty electric solenoid valve, factory-fitted to the horn
Not included: compressor, air tank, air line, fittings, relay, switch, wiring or mounting hardware beyond the flange itself. Budget for those separately, and if you are starting from a vehicle with no onboard air, read our guide to train horn install cost before you buy.
Pros
- Five chrome trumpets on one base is the biggest, most locomotive-looking cluster United Pacific sells
- The 12V solenoid valve comes fitted from the factory, so a truck with onboard air only needs an air line and a switched circuit
- United Pacific horns have a consistent reputation on Train Horn Forums for authentic train-horn tone rather than a generic air-horn blat
- Widely stocked across truck-parts dealers, with at least six retailers listing the part
- Chrome finish suits show trucks and chrome-heavy big rigs without repainting
Cons
- The 155 dB rating has a ±10 dB tolerance and no test distance, which makes it a marketing number rather than a measurement
- No published operating or maximum PSI, unlike United Pacific’s own 46129 and 46130, which are rated 150 PSI max
- Horn only: you supply air, wiring, mounting and any relay, and there is no kit version
- Dealer listings disagree on brass versus plain chrome construction, and the manufacturer does not settle it
- Six-month warranty is short next to the one-year terms common from kit brands
- Roughly $400+ is about double the four-trumpet 46130 for one extra trumpet, and no dealer we found had a single customer review to justify the premium
Alternatives
- United Pacific 46130 — the same brand’s four-trumpet chrome cluster, rated 155 dB ±10 dB with a published 150 PSI maximum, for roughly $163 to $210. Unless you specifically want five bells, this is the better value in the family. See our United Pacific 46130 review.
- United Pacific 46152 Competition Series — the heavier-built four-trumpet chrome horn with the same 12V solenoid and 150 PSI rating, typically $146 to $175. Our pick for hardware per dollar in United Pacific’s range. See the 46152 Competition Series review.
- HornBlasters Admiral 228H — a solid-brass five-chime horn sold as a complete kit with compressor and tank, around $799 to $950. Far more money, but you get a stated 150 PSI rating, a one-year warranty and the air system in the box. See our Admiral 228H review.
If your goal is a genuine five-chime locomotive sound rather than the look, the Nathan K5LA is the reference, at real-locomotive prices. For the rest of the brand’s lineup, start with the United Pacific reviews hub.
Install / compatibility notes
Air. The 46131 needs a pressurized air source. On a semi, that usually means tapping the truck’s air system through a protection valve so the horn cannot bleed the brake reservoirs; on a pickup or show vehicle it means a compressor and tank. United Pacific does not publish a pressure rating for this horn, so the sensible ceiling is the 150 PSI maximum the brand states for its 46129 and 46130. Owners on Train Horn Forums run United Pacific horns anywhere from 100 to 150 PSI and describe the top of that range as extremely loud. Our train horn PSI guide explains what pressure does to volume.
Air line size. The most repeated piece of owner advice in the United Pacific threads we read is that the “weakest link” is a restrictive valve and skinny air line. One owner described the horns as sluggish on 3/8-inch line through a 1/4-inch valve and dramatically louder after moving to 1/2-inch line and a larger valve. Treat that as user reports rather than a spec, but five trumpets need airflow, so do not starve them.
Electrical. The included solenoid is 12-volt. A 24-volt truck needs a step-down converter or a separate 24V valve. Because the solenoid is an inductive load, wire it through a relay with a fused feed rather than directly through a dash switch; our relay wiring guide covers the circuit.
Mounting. The horn hangs from a single round flange, and the assembled cluster is listed at about 17 by 17 by 15 inches. On a Class 8 truck that usually means a frame rail, a cab-roof bracket or a bumper-mounted bracket. Check the semi truck train horn guide for placement options, and confirm local rules in our state legality pages before you use it on the road.
Spares. United Pacific sells a 3-7/8 inch replacement diaphragm, part 46127-5, for roughly $6 to $8, but dealers list it only for the 3-trumpet 46127, 46129 and 46150. We could not find a diaphragm listing that names the 46131, so ask the dealer before assuming the same part fits.
- Confirm you have onboard air before buying; there is no kit version
- Cap pressure at 150 PSI, the figure United Pacific publishes for its sister models
- Run 1/2-inch line and a relay-switched 12V circuit for the solenoid
- Plan mounting around 17 × 17 × 15 inches and a package weight of 24.5 lb
Sources
- United Pacific — 5 Trumpets Chrome Train Horn 46131 spec sheet (PDF, hosted by Vehicle Safety Supply) — factory description, 155 dB ±10 dB rating, 12V solenoid included, 6-month warranty, UPC, package dimensions 20.9 × 17.6 × 18.5 in, package weight 24.5 lb, sold by the each, product photo
- United Pacific Industries (truck division) — 5 Trumpets Chrome Train Horn 46131 — official listing the spec sheet was printed from, via the brand’s former uptruckparts.com domain (site was behind bot protection at review time)
- Vehicle Safety Supply — United Pacific 5 Trumpet Chrome Train Horn 46131 — $423.55 price, in-stock status, included items, package dimensions and weight, 6-month warranty, UPC
- Fitzgerald Truck Parts — United Pacific Five Trumpet Train Horn 46131 — $399.99 price, “brass with chrome plating” material claim, 12V solenoid
- Truck Town — 5 Trumpet Chrome Train Horn, United Pacific 46131 — $405.81 sale price versus $431.59 regular, 6-month warranty, Proposition 65 note
- TruckAC — 5 Trumpets Chrome Train Horn, United Pacific 46131 — $420.61 price versus $462.67 list, “brass with chrome plating” material claim, UPC
- Chrome Country — United Pacific Chrome 5 Trumpet Train Horn — $415.99 price, sold-out status, 17 × 17 × 15 in horn dimensions, “deep bass” description
- TRUCKiD — United Pacific 46131 5 Trumpet Chrome Train Horn — additional dealer listing confirming the part number (pricing not captured)
- FinditParts — United Pacific 46131 — additional dealer listing confirming the part number (pricing not captured)
- Amazon — United Pacific 46129 3 Trumpet Train Horn — sister model’s published 150 PSI maximum and 145 dB ±10 dB rating used for the pressure comparison
- Truck Town — United Pacific 46127-5 Train Horn Diaphragm — $8.12 replacement diaphragm, fits 46127 / 46129 / 46150 only
- Vehicle Safety Supply — United Pacific 3-7/8” Train Horn Diaphragm 46127-5 — $6.14 price, 3-7/8 in diameter
- YouTube — “United Pacific – 5 Trumpet Train Horn, SUPER LOUD!” (Train Horns Nederland) — sound demo of a United Pacific five-trumpet horn
- Train Horn Forums — “I still can’t get over how good United Pacific horns sound” — owner reports on authentic tone and 150 PSI use with 1/2 in line (brand-level, 46115 model)
- Train Horn Forums — “How are my United Pacific horns?” — owner reports on 100 to 150 PSI operation, the 3/8 in line and 1/4 in valve versus 1/2 in air line upgrade, and “excellent starting horn” assessment
- Train Horn Forums — “United Pacific horn” — thread asking about the five-bell version; user comparison to Shocker-class horns on loudness and authenticity
Train Horn Hub aggregates publicly available data. We do not test products in-house. All trademarks belong to their respective owners.
The 46131 is for the semi or show-truck owner with onboard air who wants United Pacific's tone in the biggest five-trumpet chrome package the brand makes and is willing to pay roughly $400 for the look. Buyers who care about published specs or value should take the four-trumpet 46130 or 46152 instead.
Frequently asked questions
Quick answers to the questions people ask most about this topic.
- How loud is the United Pacific 46131 really?
- United Pacific advertises 155 dB with a ±10 dB tolerance and does not state a test distance, so the honest range is 145 to 165 dB under unknown conditions. No independent measurement of this model is published; owner reports describe United Pacific horns as extremely loud at 150 PSI with 1/2-inch air line.
- Does the 46131 come with a compressor or air tank?
- No. The box contains the five-trumpet chrome horn assembly on its mounting flange and a factory-fitted 12V heavy-duty electric solenoid valve. You supply air from a semi's onboard air system or an aftermarket compressor and tank, plus air line, wiring and a relay.
- What PSI does the United Pacific 46131 run at?
- United Pacific does not publish a pressure rating for the 46131. The brand rates its sister 46129 and 46130 horns at 150 PSI maximum, and owners on Train Horn Forums run United Pacific horns between 100 and 150 PSI, so 150 PSI is the sensible ceiling until the manufacturer states otherwise.
- How big is the 46131 and how much does it weigh?
- Dealers list the assembled horn at about 17 inches long, 17 inches wide and 15 inches tall. United Pacific's spec sheet gives a package size of 20.9 by 17.6 by 18.5 inches and a package weight of 24.5 pounds, so the bare horn is somewhat lighter than that shipping figure.
- Is the United Pacific 46131 made of brass?
- Fitzgerald Truck Parts and TruckAC list it as brass with chrome plating, but Vehicle Safety Supply, Truck Town and Chrome Country say only chrome, and United Pacific's own spec sheet does not state the base metal. Dealers describe the brand's four-trumpet 46152 as zinc alloy, so treat the brass claim as unconfirmed.
