Oil Suction Gun & Fluid Extractor Manufacturer & Exporter - Oil Suction Guns & Transfer Pumps

Frequently Asked Questions: Oil Suction Guns & Fluid Extractors

What is an oil suction gun?

An oil suction gun (also called a fluid extractor pump or manual oil extractor) is a handheld pump that uses vacuum pressure to draw oil, coolant, transmission fluid and other liquids out of engines, gearboxes and reservoirs. You pump the handle to create negative pressure inside the barrel, which pulls fluid up through a hose. Unlike drain plug methods, suction guns work from the top, so you don't need to get under the vehicle or remove any plugs. STAR manufactures 17 models from 300 ml to 1,000 ml capacity.

Does an oil suction gun get all the oil out?

A quality suction gun typically extracts 95 to 99% of the oil from an engine sump, which is comparable to drain plug methods. The key factor is hose positioning: the suction hose must reach the lowest point of the sump. Some engine designs have baffles or irregular sump shapes that can trap small amounts of oil regardless of extraction method. For most passenger cars, suction extraction through the dipstick tube removes as much oil as draining from the plug.

What is the difference between a suction gun and a transfer pump?

A suction gun extracts fluid in one direction (out of a reservoir into the barrel), while a transfer pump moves fluid in both directions (extract and dispense) in a single stroke. Our transfer pumps (S-901, S-902, S-903) come with 8 feet of vinyl hose for dual-direction operation, making them ideal for moving fluid between containers. Suction guns (S-905 to S-908) come with a 12 inch hose and are designed primarily for extraction from gearboxes, differentials and transmissions.

Can I use a suction gun for transmission fluid and gear oil?

Yes. Oil suction guns are widely used for extracting transmission fluid, differential gear oil, power steering fluid and coolant. For thick gear oils (SAE 75W-90 or 80W-140), warm the vehicle first to reduce viscosity, which makes extraction faster and more complete. The NBR (nitrile rubber) seals in STAR suction guns are compatible with all petroleum-based fluids. For very thick fluids, the larger capacity S-905/XL (700 ml) or S-905/1000 (1,000 ml) models reduce the number of extraction cycles needed.

Steel vs plastic suction gun: which is better?

Steel suction guns (S-905 series) are more durable and better for heavy daily workshop use, while plastic models (S-908 series) are lighter, corrosion-free and better for marine or chemical environments. Steel models withstand drops and rough handling. Plastic models won't rust if exposed to water or coolant. For automotive workshops, steel is the standard choice. For boat maintenance or environments where corrosion is a concern, plastic is preferred. We also offer aluminium die cast head models (S-902, S-905DC) as a middle ground: lighter than steel but stronger than plastic.

What size hose fits through a dipstick tube?

Most automotive dipstick tubes accept a 6 mm to 8 mm (1/4 inch) outer diameter hose. Our suction guns come with 12 inch flexible vinyl hoses that fit standard dipstick openings. For transfer pumps, the 8 foot hose is designed for container-to-container transfer rather than dipstick extraction. If you need to extract through a dipstick tube, use a suction gun model (S-905 to S-908) rather than a transfer pump.

How do I clean a suction gun after use?

After each use, pump clean solvent or kerosene through the barrel and hose to flush out residual oil. Then pump air through to dry the internals. For the exterior, wipe with a clean rag. Never leave used oil sitting in the barrel for extended periods as it can degrade the NBR seals. If switching between different fluid types (e.g. from gear oil to coolant), flush thoroughly to avoid cross-contamination. Store with the barrel empty and the hose detached.

What is the S-906 C Type suction gun?

The S-906 C Type features a slim 44.45 mm (1.75 inch) barrel diameter, compared to the standard 57.15 mm (2.25 inch) on other models. This compact design enhances grip and manoeuvrability in tight spaces. Available in 300 ml (S-906) and 500 ml (S-906/L) capacities with a 9 inch steel hose. The slim profile makes it ideal for precision fluid extraction in confined engine compartments where a full-size suction gun won't fit.

What fluids should I NOT use with a suction gun?

Do not use suction guns with gasoline, acetone, MEK, strong solvents or corrosive chemicals. These will damage the NBR rubber seals and PVC hoses, causing leaks and pump failure. For petroleum-based fluids (engine oil, gear oil, ATF, coolant, brake fluid), all STAR suction guns work safely. For chemical applications requiring solvent resistance, use our plastic body models (S-903, S-908) which offer better chemical compatibility than steel models.

Suction extraction vs drain plug: which removes more oil?

Both methods remove approximately the same amount of oil when done correctly. Drain plug removal relies on gravity, which can leave oil trapped in horizontal passages and baffles. Suction extraction pulls oil from the lowest point of the sump, which can actually reach pockets that gravity misses. The main advantage of suction is convenience: no jack, no crawling under the vehicle, no risk of cross-threading the drain plug. Many professional workshops now prefer suction extraction for routine oil changes.

What capacity suction gun do I need?

For passenger cars (4 to 5 litre oil capacity), a 500 ml suction gun requires 8 to 10 pump cycles to complete an oil change. The 700 ml S-905/XL reduces this to 6 to 7 cycles, and the 1,000 ml S-905/1000 needs only 4 to 5 cycles. For motorcycles and small engines, the compact 300 ml S-906 C Type is sufficient. For differential and gearbox service (typically 1 to 2 litres), any 500 ml model works well. Choose based on how many vehicles you service daily: higher capacity means fewer refill cycles and faster throughput.

Do you offer OEM oil suction gun manufacturing?

Yes. We provide full OEM and private label manufacturing with custom branding, specifications and packaging for all 17 suction gun and transfer pump models. We supply distributors and industrial buyers in over 27 countries. Steel, aluminium, plastic and clear tube variants are all available for OEM. Visit our OEM partnership page for details on bulk orders and export supply.