Best AC Leak Dye Injector (2026)

Warm air from the vents on a hot drive usually means refrigerant has escaped somewhere in the loop, and a small leak can hide for weeks behind a fitting or a hose. The best ac leak dye injector puts fluorescent dye into the system through the low side port, so the dye travels with the oil and shows at the leak point. This guide compares the injectors on capacity, couplers, body material and warranty, so you can match a pick to your system and your garage.

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Picks for the garage

#	Product	Shop Score	Buy
1	Qnbes AC Oil Dye Injector	9.5/10	Buy on Amazon
2	Lichamp AC Oil Injector R134A	9.5/10	Buy on Amazon
3	GallopMax R1234YF & R134A AC Oil Dye Injector Kit	9.5/10	Buy on Amazon
4	gohantee R12 AC Oil dye Injector for R134a R22 2oz	9.4/10	Buy on Amazon
5	KPEOY Oil Dye Injectors Kit	9.3/10	Buy on Amazon

1

Qnbes AC Oil Dye Injector

Qnbes·9.5/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A solid brass 2 oz oil dye injector for R134A, R12 and R22 systems with 1/4 in SAE male and female fittings and a 2 year service term.

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Pros

• Solid brass body, wear and corrosion resistant
• Fits R134A, R12 and R22 systems
• 2 oz (60 ml) capacity with fast filling
• 2 year service term with a 12 hour reply promise

Cons

• No R1234YF coupler stated
• No oil checker or measuring cup included
• No weight or dimensions stated
• No safety listing stated

2

Lichamp AC Oil Injector R134A

Lichamp·9.5/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

An aluminum alloy AC oil and dye injector for R134a, R1234yf and R410A with 2 oil checkers, a knurled handle and a 1/4 oz to 2 oz capacity range.

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Pros

• Fits R134a, R1234yf and R410A systems
• 1/4 oz to 2 oz capacity with a 1/4 in female hose fitting
• Aluminum alloy body with heavy-duty brass couplers
• 2 oil checkers included, plus a knurled non-slip handle

Cons

• No warranty term stated
• No safety listing stated
• Bulky at 3.35 x 2.36 x 9.06 in
• Twist handle needs a firm grip for a full 2 oz fill

3

GallopMax R1234YF & R134A AC Oil Dye Injector Kit

GallopMax·9.5/10 Shop Score

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The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A 2 oz aluminum AC oil dye injector kit for R134A and R1234YF with separate snap-on couplers, 2 oil checkers and a 2 oz measuring cup.

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Pros

• Separate R134A and R1234YF snap-on couplers
• Laser-engraved scale from 1/4 oz to 2 oz
• 2 oil checkers and a 2 oz measuring cup included
• Aluminum body with a twist-to-inject handle

Cons

• No warranty term stated
• No weight or dimensions stated
• No safety listing stated
• No R12 or R22 fit stated

4

gohantee R12 AC Oil dye Injector for R134a R22 2oz

gohantee·9.4/10 Shop Score

i

The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A rugged all-metal 2 oz R12 oil dye injector for R12, R22 and R134a with a needle style valve and 1/4 in SAE male and female fittings, rated 600 to 3000 PSI.

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Pros

• 600 to 3000 PSI range stated
• Rugged all-metal 2 oz canister
• Needle style valve between gauge set and hose
• Adds oil or dye without extra refrigerant

Cons

• No warranty term stated
• No weight stated
• No safety listing stated
• No R1234YF fit stated

5

KPEOY Oil Dye Injectors Kit

KPEOY·9.3/10 Shop Score

i

The Shop Score runs from 9.2 to 9.8 and weighs performance (35%), build (25%), value (25%), safety (10%, where it applies) and warranty (5%), using only what the manufacturer and the listing publish. How we pick ›

A compact 30 ml (1 oz) hand-push oil dye injector with a 1/4 SAE connector, a 21.5 cm blue flexible tube and a transparent viewing window.

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Pros

• Transparent viewing window shows liquid level
• One-handed push handle with ergonomic grip
• 21.5 cm flexible tube with metal threaded connectors
• Compact 8.5 x 0.6 x 0.6 in size for easy carry

Cons

• 30 ml capacity, the smallest here
• Plastic body, not metal like the others
• Warranty field shows 0.2 with no term stated
• No safety listing stated

Compared on paper

Every rating comes from the brand’s listing and is not a shop test (gathered 12 November 2026). Where a listing contradicts itself, both figures are shown.

How the points were given

Each injector is scored on performance, build, value, safety and warranty, with the weights published on our How We Pick page. None states a UL, ETL or CSA listing, so no pick earns safety points, and only 1 of the 5 states a warranty term with a clear length.

No score drops under 9.2 or climbs past 9.8; a tool’s place inside those bounds is set by its weighted point total.

What the listings tell you

We read 5 injector listings. 2 of the 5 cover both R134A and R1234YF, while 3 mention brass somewhere in the build. All but 1 list a 2 oz capacity, and the remaining 1 lists 30 ml. Only 1 states a warranty term with a clear length, and none states a safety listing.

Best AC leak dye injector buying guide

Capacity

Capacity decides how much oil or dye you can push in one fill. Most of the picks here hold 2 oz, and the GallopMax and Lichamp scales run from 1/4 oz to 2 oz, or 7.5 ml to 60 ml, so you can meter a small amount. The KPEOY pick holds 30 ml, or 1 oz, which suits a top-up rather than a full fill.

Refrigerant fit

Match the injector to the refrigerant in the system. GallopMax and Lichamp list both R134A and R1234YF, Qnbes and gohantee list R134A, R12 and R22, and Lichamp also lists R410A. A pick that lists only older refrigerants will not suit a car that runs R1234YF.

Couplers and fittings

Most of these injectors connect through the low side with a 1/4 in SAE fitting. GallopMax ships separate R134A and R1234YF snap-on couplers, Lichamp includes extra couplers for both, and gohantee uses a needle style valve between the gauge set and the hose. Check the fitting on your car before ordering, since the wrong coupler will not seat on the port.

Body and seals

Brass and aluminum dominate this set: Qnbes uses a solid brass body, Lichamp pairs an aluminum alloy body with heavy-duty brass couplers, and gohantee uses aluminum alloy. KPEOY is the plastic pick, with brass fittings and a rubber hose. A tight seal matters more than the body metal, since a leaking injector wastes dye and oil at the port.

Pressure range

Only gohantee states a pressure range, 600 to 3000 PSI. The other picks state no pressure figure, so do not assume a range the listing does not give.

Garage Fit Check

• Check the coupler before the first job: GallopMax and Lichamp include couplers for R134A and R1234YF, while Qnbes and gohantee fit R134A, R12 and R22.
• Keep the small parts together: the GallopMax kit lists 2 oil checkers, a 2 oz measuring cup and a manual, and Lichamp includes 2 oil checkers.
• Mind the size on the shelf: the KPEOY pick measures 8.5 x 0.6 x 0.6 in, and the Lichamp pick measures 3.35 x 2.36 x 9.06 in.
• Match the capacity to the job: all but 1 of the 5 picks hold 2 oz, and the KPEOY pick holds 30 ml.
• Store the injector with its couplers and checkers in one box so nothing goes missing before the next job.

FAQ: garage tools

How do you use AC leak detector dye?

Connect the injector to the low side of the system and push the dye in with the handle, as the listing describes. GallopMax describes the steps as starting the air conditioning on maximum cooling, adding the oil or dye to the body, connecting the low side check valve, opening the safety valve and turning the handle clockwise until the oil is injected. The dye then travels with the oil and shows at the leak point.

How do you use AC leak dye?

Add the dye through the low side with an injector, then run the system so the dye circulates with the oil. Lichamp describes connecting the injector to the low side and twisting the handle until you reach the desired amount, while KPEOY describes pushing the piston with the handle for a steady flow. Check the fittings and hoses for dye at the leak point once the system has run.

How much dye does an AC system need?

The injectors here hold 2 oz, except the KPEOY pick at 30 ml, and the GallopMax and Lichamp scales run from 1/4 oz to 2 oz so you can meter the amount. The listings describe adding the required oil to the body, so match the amount to the job and the oil the system calls for.

Can one injector fit R134A and R1234YF?

Yes, 2 of the 5 picks list both. GallopMax ships separate snap-on couplers for R134A and R1234YF, and Lichamp includes extra couplers for both. Check the coupler in the kit before connecting, since a coupler made for one system will not seat on the other port.

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