Which bleed kit fits Shimano R9300, Ultegra R8270, and SRAM Maven Bronze? A 2026 compatibility guide

The bleed kit that bled your XT brakes last winter may not fit the bike you bought this spring. Two parallel changes landed in the 2026 model year, one on the Shimano side and one on the SRAM side, and both quietly broke the assumption that a kit bought a few years ago will still fit. The Shimano change is a funnel-thread move from M5 to M7 on the new Dura-Ace R9300 and Ultegra R8270 levers. The SRAM change is a thicker bleed block on the Maven Bronze caliper, sized 5.0 mm rather than the 4.0 mm block the older Code generation used. Neither change is large in absolute terms; both are large enough to leave the kit on your bench refusing to seal at the lever or seat against the caliper.

This guide is the compatibility lookup we wish we had when the first R9300 lever rolled into the shop. We'll walk through what specifically changed on each system, which Bleedkit.com kits in our catalog already fit each one, and where Magura and Tektro fit on the spec map. The cheat sheet at the bottom is the table to bookmark.

Why the 2026 funnel and block changes matter

Two changes hit bleed-kit fitment almost simultaneously. The first is on Shimano's road levers: the redesigned STR funnel adapter on the 2026 Dura-Ace and Ultegra generations uses an M7 thread rather than the M5 that the XT-era kits ship with. The second is on SRAM's new Maven caliper family, where the Bleeding Edge port spec moved to a thicker brake-specific block. The 2026 cyclingarchives.com bleed guide summarized both changes in one paragraph:

The brake half of that group uses a redesigned STR funnel adapter with an M7 thread. If you upgraded to R9300 or the matching Ultegra R8270, the older M5 funnel from your XT bleed kit will not fit. The Maven Bronze brought heavy-duty four-piston braking to the trail and enduro market with a redesigned Bleeding Edge port that uses a slightly thicker brake-specific block (5.0 mm rather than the older Code's 4.0 mm). Park Tool released a refreshed BKM-1.3 kit in February 2026 with updated Bleeding Edge fittings.

Read together, the changes mean the same thing for a workshop mix: a single all-purpose kit from a few years ago is now in the awkward middle between current Shimano road and current SRAM Maven. The fix is system-specific kit selection, which is the way Bleedkit.com has always built kits. The Workshop Gold Mineral Oil Master Bleed Kit carries the dropbar adapter and the right blocks for the existing Shimano mineral-oil family; the SRAM side gets its own kit family because the fluid is different.

Shimano: R9300, R8270, and the M5 vs M7 funnel

Pre-2026 Shimano hydraulic brakes, from XTR and XT down through Saint, SLX, Deore, Alivio, and the drop-bar Dura-Ace, Ultegra, 105, GRX, and Tiagra generations through the R9200 / R8170 era, share a common bleed-funnel thread: M5, mounted to the lever's bleed port through a brass adapter on the road kits and direct on the flat-bar kits. Service documentation distinguishes the thread by port style: Back Port, Front Port, and Top Port designs all take M5; the new Middle Port style is what takes M7. The R9300 and R8270 lever bodies use the Middle Port pattern.

What this means in practice: any Bleedkit.com Shimano kit currently in our catalog is sized to the M5 standard. The Premium Shimano Bleed Kit covers all flat-bar Shimano hydraulic brakes; the Premium Road Shimano Bleed Kit adds the drop-bar adapter for the pre-2026 Dura-Ace, Ultegra, 105, GRX, and Tiagra generations. Both are correct kits for the bikes that were on the showroom floor through late 2025. Neither carries an M7 funnel for the R9300 / R8270 lever; that adapter is a separate accessory that Bleedkit.com has flagged as in development for the workshop kit family.

For a mechanic with a mixed Shimano fleet, the practical move is to keep an M5 kit on the bench for everything except R9300 and R8270, and to source an M7 adapter separately for the newest road builds until the next-generation workshop kit ships. The fluid itself is unchanged: Shimano mineral oil, the same yellow bottle as before. The thread change is the only spec move at the lever side.

SRAM: Maven Bronze and the 5.0 mm Bleeding Edge block

SRAM's Maven launched in early 2024 as a heavy-duty four-piston platform aimed at enduro and downhill, with Maven Bronze as the volume-tier offering in 2025–26. Two changes matter for bleed-kit fitment. First, Maven is SRAM's first high-end mountain brake to run mineral oil instead of DOT 5.1 — SRAM co-developed Maxima Mineral Brake Oil specifically for Maven's new seal compounds, and SRAM's launch literature is explicit that using anything other than Maxima Mineral Brake Oil voids the warranty. Second, the Bleeding Edge port spec moved to a thicker 5.0 mm bleed block where the prior Code generation used a 4.0 mm block; the Bleeding Edge fitting itself looks similar.

The mineral-oil call is a meaningful break with the prior Code generation. SRAM made the same fluid move on the budget-tier DB8 back in 2022; Maven brings it to the high-end mountain market for 2024–26. The rest of the SRAM hydraulic family — Code, Level, Guide, G2, and the Force / Red AXS road brakes — still runs DOT 5.1.

The Ultimate SRAM Bleed Kit covers SRAM's hydraulic brake family at the hardware level: the Edge assembly fits the Bleeding Edge port on Maven, Code, Avid Elixir, Juicy, and older Formula calipers alike, and the kit ships both block thicknesses (4.0 mm for older Code / Avid, 5.0 mm for Maven). The fluid call is on the mechanic: Maven and DB8 take mineral oil, everything else SRAM takes DOT 5.1. The shop habit that matters most when servicing both fluid types on the same SRAM kit is the syringe contamination boundary — a syringe that has touched DOT cannot then touch a Maven, since the residual DOT will attack the mineral-oil seal stack; the reverse also holds. Practical workshop routine: designate one Ultimate kit per fluid family, or replace the syringes between fluid jobs. The SRAM Workshop DOT Bleed Kit is the volume option for shops with a DOT-only SRAM rotation (Code, Level, Guide, G2, Force / Red AXS, plus Avid Elixir and Juicy legacy).

Magura, Tektro, and other mineral systems (briefly)

Magura's MT family runs on Royal Blood, Magura's own mineral-oil formulation. The lever uses a Luer-slip funnel rather than a threaded brass funnel, and the caliper port takes an M6 fitting rather than the M5 / M7 spread that Shimano uses. The Premium Gold Magura MT Bleed Kit is built specifically to the Magura interface; the Royal Blood fluid is included in the kit at 100 ml.

Tektro and TRP run on mineral oil as well, and share enough fitting geometry with Shimano flat-bar levers that one kit can cover both with the right adapter set. The Premium Gold TRP/Tektro Bleed Kit carries the brass M5-to-M6 adapter for Tektro / TRP and the flat-bar Shimano blocks together, so a workshop running a Tektro-equipped fleet alongside Shimano can stay on one kit family. The kit does not cover Shimano drop-bar brakes; those need the Premium Road or Workshop Master kits with the dropbar adapter.

Formula Cura is the outlier: the Cura uses a non-standard fitting that the Ultimate SRAM kit explicitly does not cover. Cura service requires the Formula-specific kit, which sits outside the Bleedkit.com current catalog.

Compatibility cheat sheet

Brake system	Fluid	Lever funnel	Caliper block	Recommended Bleedkit.com kit
Shimano XTR, XT, Saint, Zee, SLX, Deore, Alivio, Acera, Alfine, Metrea (flat bar)	Shimano mineral oil	M5 brass thread	Flat-bar 2 or 4-piston block	Premium Shimano or Premium Road Shimano for combined fleets
Shimano Dura-Ace R9200, Ultegra R8170, 105, GRX, Tiagra (pre-2026 drop bar)	Shimano mineral oil	M5 brass thread + dropbar adapter	Smaller dropbar block	Premium Road Shimano or Workshop Master Mineral Oil
Shimano Dura-Ace R9300, Ultegra R8270 (2026+ drop bar)	Shimano mineral oil	M7 brass thread	Smaller dropbar block	M7 adapter required; current Bleedkit.com kits do not include it. Workshop replacement in development.
SRAM Code (pre-Maven), Level, Guide, G2, Force / Red AXS, Avid Elixir / Juicy, older Formula	DOT 5.1	Edge assembly	4.0 mm block (Code)	SRAM Ultimate or SRAM Workshop DOT
SRAM Maven (Ultimate, Silver, Bronze, Base) and SRAM DB8	SRAM Maxima Mineral Brake Oil	Edge assembly	5.0 mm block (Maven)	SRAM Ultimate (Edge + 5.0 mm block; run with mineral oil syringe)
Magura MT (MT4, MT5, MT7, MT8 family)	Magura Royal Blood (mineral)	Luer-slip funnel	Magura MT block	Premium Gold Magura MT
Tektro, TRP hydraulic (flat bar)	Mineral oil	M5-to-M6 brass adapter	Flat-bar 2 or 4-piston block	Premium Gold TRP/Tektro
Formula Cura	Mineral oil	Cura-specific	Cura-specific	Not covered by current Bleedkit.com catalog

Built in Ljubljana, since 2011

Bleedkit.com is distributed by Unior USA's parent organization Euro Toolworks. The brand was founded in 2011 in Ljubljana, Slovenia, out of shop-bench frustration with one-size-fits-most bleed kits. Every kit in the catalog is built for a specific brake-system family rather than a lowest-common-denominator pattern, which is why a Shimano kit and a SRAM kit live as separate SKUs instead of one universal box.

Unior has been forging hand tools in Zreče since 1919, and is the official technical partner of multiple World Tour and downhill teams. The Bleedkit.com distribution arrangement extends that workshop-tool philosophy into the hydraulic-fluid side of the bench, where contamination chemistry rules and the right kit for the right system is the only setup that holds up over a season.

Pro tip from our mechanics

If you service a mixed fleet, the single move that saves the most rework is sorting the kit drawer by fluid first and by lever-thread second. One drawer for mineral oil (Shimano, Magura, Tektro, SRAM Maven, SRAM DB8), one drawer for DOT (SRAM Code / Level / Guide / G2 / Force / Red AXS, Avid Elixir / Juicy, older Formula), and a wipe-down with a clean rag between every job. The drawer split is the contamination boundary that matters; the thread split inside the mineral-oil drawer is what tells you which kit to reach for once you've identified the system on the bike in the stand.

For a single-kit workshop that's adding a 2026 R9300 or R8270 build to the rotation, the bridge kit until the M7 workshop kit ships is the existing Workshop Gold Mineral Oil Master Bleed Kit → plus a separate M7 adapter sourced for the new lever. The master kit already covers everything else in the mineral-oil family, so the only gap is the funnel adapter for the new road lever.

See all bleed kits at Unior USA → /collections/bleed-kits