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Details
| Specification | Value |
|---|---|
| Brand | 3RG |
| Category | coolant expansion tank |
OE numbers (4)
Search by this OE number to find compatible parts
- AUDI / SEAT / SKODA / VW—1K0121407
- AUDI / SEAT / SKODA / VW—1K0121407A
- AUDI / SEAT / SKODA / VW—1K0121407F
- AUDI / SEAT / SKODA / VW—3B0121321
Where this part fits
Original-fit position for OE 1K0121407F. The red ring marks where this part installs on the vehicle.
What's in the kit
About this product
When coolant expansion tank performance matters, the 3RG 81741 delivers — built to the same dimensional and material standards as the original part it replaces. The part is built to the following specification: Supplementary Article/Info 2: 567. Each dimension is checked against the OEM reference to ensure the component seats and functions correctly first time. Compatible with AUDI, SEAT, SKODA, VW vehicles; use the vehicle selector above to confirm exact fitment for your make, model, and engine variant. Fitment data is sourced from TecDoc, the authoritative European parts catalogue. This part supersedes original equipment references: 0026012176, 00263001, 01414, 03817 and 74 more. Matching these numbers confirms a like-for-like replacement with no loss of function. 3RG is a recognised supplier of automotive replacement components to independent workshops and dealer networks across Europe. All parts are sourced from authorised distribution channels and carry full manufacturer traceability — you receive exactly the same component supplied to professional garages and dealer workshops. If fitment or specifications do not match your vehicle, our technical team can help identify the correct alternative — use the vehicle selector or contact us with your VIN for a guaranteed-fit recommendation. Replacing worn components on schedule preserves your vehicle's safety, reliability, and resale value — and aftermarket parts from established brands deliver OEM-equivalent performance at a fraction of the dealer price. Every part is dispatched with tracked delivery and a 14-day money-back guarantee with hassle-free returns.
Suitable cars
Equivalent products (76)
Show all 76 OE numbers
coolant expansion tank 3RG 81741 — compatible car models
| Car models | AUDI: A3 (8P1), A3 Convertible (8P7), A3 Sportback (8PA), Q3 (8UB, 8UG), TT (8J3), TT Roadster (8J9); SEAT: ALHAMBRA (710, 711), ALHAMBRA VAN (711), ALTEA (5P1), ALTEA XL (5P5, 5P8), LEON (1P1), TOLEDO III (5P2); SKODA: OCTAVIA II (1Z3), OCTAVIA II Combi (1Z5), RAPID (NH3, NK3, NK6), RAPID Spaceback (NH1), SUPERB II (3T4), SUPERB II Estate (3T5), YETI (5L); VW: BEETLE (5C1, 5C2), BEETLE Convertible (5C7, 5C8), CADDY ALLTRACK IV Box Body/MPV (SAA), CADDY ALLTRACK IV MPV (SAB), CADDY III Box Body/MPV (2KA, 2KH, 2CA, 2CH), CADDY III MPV (2KB, 2KJ, 2CB, 2CJ), CADDY IV Box Body/MPV (SAA, SAH), CADDY IV MPV (SAB, SAJ), CC B7 (358), EOS (1F7, 1F8) (+1 more) |
|---|---|
| Engines | 1.2 TSI; 1.2 TFSI; 1.4 TFSI; 1.8 TFSI; 1.4 TSI; TDI; 1.6; 2.0 TDI; 1.4; 1.0 TSI |
| Year of manufacture | 2003-2023 |
| Manufacturer article number (MPN) | 81741 |
| OE part numbers | 1K0121407, 1K0121407A, 1K0121407F, 3B0121321 |
Compatibility check
Loading vehicle data…
Please wait while we load vehicle compatibility information.Description and what's included
3RG 81741 coolant expansion tank. Supplementary Article/Info 2: 567
- 1x coolant expansion tank
Shipping, returns, warranty
Free UK delivery on orders over £99.00. Tracked standard shipping.
- Standard delivery: 5–9 business days
- Order before 5pm — ships the next working day
- Free returns within 14 days
- All parts backed by manufacturer warranty
Warranty: 12-month manufacturer warranty on all parts. 14-day money-back guarantee if the part doesn't fit your vehicle.
Frequently Asked Questions
Is this coolant expansion tank compatible with my car?
This coolant expansion tank fits AUDI, SEAT, SKODA, VW vehicles. Use the vehicle selector at the top of the page to check exact compatibility — enter your car's make, model, and engine for a confirmed fitment match. All fitment data is verified through TecDoc.
What specifications does this 3RG coolant expansion tank have?
This 3RG coolant expansion tank has the following specifications: Supplementary Article/Info 2: 567. Check the full specifications table above for complete details.
What OE part numbers does this coolant expansion tank replace?
This coolant expansion tank replaces OE part numbers: 1K0121407, 1K0121407A, 1K0121407F, 3B0121321. Cross-reference these numbers with your vehicle's original part number to confirm compatibility.
How much does a coolant expansion tank cost?
This 3RG coolant expansion tank is available for £25.99. Coolant expansion tank prices vary depending on brand, specifications, and vehicle compatibility. 3RG parts offer a balance of quality and value, backed by our 14-day money-back guarantee.
How do I know when to replace my coolant expansion tank?
Regular inspection of your coolant expansion tank is recommended as part of routine vehicle maintenance. Watch for changes in performance, unusual noises, or visual signs of wear. Consult your vehicle's owner manual for manufacturer-recommended replacement intervals specific to your make and model.
What tools do I need to replace a coolant expansion tank?
Tools needed: hose clamp pliers, flat-head screwdriver, 8mm socket, coolant top-up bottle. Difficulty: Easy DIY. Safety warning: Only open the expansion tank cap when the engine is completely cold -- coolant system is under pressure when hot and will spray scalding fluid if opened.
Can I use this part as a replacement for OE 1K0121407?
Yes, this 3RG coolant expansion tank is a direct replacement for OE part number 1K0121407. It is manufactured to meet or exceed original equipment specifications, ensuring proper fitment and performance. All cross-reference data is verified through TecDoc.
Related categories
Common OE numbers for this part
Common original equipment numbers linked to stocked alternatives.
