--- product_id: 646464652 title: "Bicycle hydraulic brake caliper piston oil leakage repair parts maintenance upgrade kit for Shimano SLX M675 M7000 M7100 XT RS805 M785 M8000 M8100 XTRM9020 R9170 M9000 M9100 calipers, Black" brand: "exnavi" price: "VT31600" currency: VUV in_stock: false reviews_count: 5 category: "Exnavi" url: https://www.desertcart.vu/products/646464652-bicycle-hydraulic-brake-caliper-piston-oil-leakage-repair-parts-maintenance store_origin: VU region: Vanuatu --- # Turbine fan heat dissipation ±5μm precision machining Complete piston & seal kit Bicycle hydraulic brake caliper piston oil leakage repair parts maintenance upgrade kit for Shimano SLX M675 M7000 M7100 XT RS805 M785 M8000 M8100 XTRM9020 R9170 M9000 M9100 calipers, Black **Brand:** exnavi **Price:** VT31600 **Availability:** ❌ Out of Stock ## Summary > 🚴‍♂️ Upgrade your ride with precision and power—stop leaks before they stop you! ## Quick Answers - **What is this?** Bicycle hydraulic brake caliper piston oil leakage repair parts maintenance upgrade kit for Shimano SLX M675 M7000 M7100 XT RS805 M785 M8000 M8100 XTRM9020 R9170 M9000 M9100 calipers, Black by exnavi - **How much does it cost?** VT31600 with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.vu](https://www.desertcart.vu/products/646464652-bicycle-hydraulic-brake-caliper-piston-oil-leakage-repair-parts-maintenance) ## Best For - exnavi enthusiasts ## Why This Product - Trusted exnavi brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Heat? No Sweat!:** Innovative turbine fan design accelerates heat dissipation, keeping your brakes cool under pressure. - • **Lightweight & Durable:** Crafted from reinforced polyester resin, this kit weighs just 9g, combining strength with minimal added weight. - • **Precision Perfect Fit:** Ultra-tight ±5μm tolerance ensures flawless caliper piston alignment for peak braking performance. - • **All-in-One Rebuild Kit:** Includes pistons, square profile seals, and sealing rings—everything you need to restore your Shimano hydraulic brakes. - • **Mineral Oil Compatible Only:** Specifically engineered for Shimano mineral oil systems—avoid DOT fluids to maintain optimal seal integrity. ## Overview This Shimano-compatible hydraulic brake caliper piston repair kit features ultra-precise machining with ±5μm tolerance and a heat-dissipating turbine fan design. Made from reinforced polyester resin, it includes all necessary pistons and seals for a full caliper rebuild, optimized exclusively for mineral oil brake systems. Lightweight at 9g, it’s the professional’s choice for restoring flawless braking performance and preventing costly leaks. ## Description Caliper Parts. Material: Reinforced polyester resin, rubber Brake medium compatibility: Mineral Oil Brake compatibility: Service parts for shimano SLX XT XTR hydraulic disc brake calipers Weight weighed: 10.6g Color: Black Caliper Piston Kits Include: 2x caliper pistons OD0.862 x H0.3465inch(OD21.9 x H8.8mm); 2x square profile piston seals ID0.854 x 0.086inch; 2x sealing rings for brake caliper 0.236 x 0.059inch(6 x 1.5mm); 2x sealing rings for line connection 0.2559 x 0.0394inch(6.5 x 1mm). TIPS: ONLY APPLICABLE TO MINERAL OIL, NOT APPLICABLE TO DOT OIL OR OTHER BRAKE FLUIDS, CLEAN THE CERAMIC RESIDUE BEFORE INSTALLATION!！ Review: I was having issues with my M785 series Shimano XT front brake caliper leaking and contaminating my brake pads. Took a chance on these as they were cheap and could be delivered quick. Pulled the original pistons out and discovered the problem was the ceramic was broken and chipped. It's a whole process as you have to take apart the caliper and completely re-bleed the system. This kits comes with all the new o-rings you need to rebuild the caliper like new. Fast-forward over a year and now having the same issues with the back calipers: broken ceramic piston. Came here to purchased the same resin set. Best part is there is no ceramic to break. Not sure how well the resin pistons will hold up "long term" but I've been riding the front set for over a year now. Review: I needed to replace the pistons in my GRX disc caliper as one cracked after pushing my brakes past their limit on a very tough (read dumb) ride. The caliper disassembly and rebuild was straightforward with the pistons and piston seals. I did not use the kit’s smaller o-rings. After a couple of fluid bleeds, the brakes pumped up nicely and my original lever feel has been restored. I do not see any leaks or reason to believe they will start leaking. Although my measurements show the EXNAVI pistons as 0.01mm larger than the OEM version, be mindful that 0.01 is within the error of this type of measurement tool and technique. I run a machine shop and have done a ton of mechanical repairs in all sorts of machines over the years and had no qualms about dropping these replacement pistons in. Although I can’t specifically pinpoint the exact material these are made of, it does appear to be a ceramic. I would even say that the surface finish appears to be smoother than the OEM pistons - perhaps that’s a good thing? Overall, If I ever need to repair another caliper, I would have no hesitation to buy this kit again. ## Features - Is your Shimano SLX XT XTR hydraulic brake caliper leaking Is the ceramic piston broken Or to make a small friction between the discs This is what you need! - SERVICE CALIPER PISTON KIT,Product size OD0.862xH0.3465inch(OD21.9xH8.8mm) Lightweight 0.15 oz (4g) - Suitable for Shimano SLX M675 M7000 M7100 XT R8070 RS785 RS805 M785 M8000 M8100 XTRM9020 R9170 M9000 M9100 brake calipers - High-precision machining The outer diameter is coreless grinding, the outer diameter tolerance is plus or minus 5um, the roundness is 3um, and the roughness is Ra0.4um.The hurricane heat dissipation shape, the front turbine fan-shaped fan wind heat dissipation, to make the heat dissipation faster! - International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B08HD94YKC | | Country of Origin | USA | | Item Weight | 9 g | | Item part number | EX21988 | | Manufacturer | EXNAVI | ## Images ![Bicycle hydraulic brake caliper piston oil leakage repair parts maintenance upgrade kit for Shimano SLX M675 M7000 M7100 XT RS805 M785 M8000 M8100 XTRM9020 R9170 M9000 M9100 calipers, Black - Image 1](https://m.media-amazon.com/images/I/51RPLreuAjL.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ Review *by R***R on 26 January 2025* I was having issues with my M785 series Shimano XT front brake caliper leaking and contaminating my brake pads. Took a chance on these as they were cheap and could be delivered quick. Pulled the original pistons out and discovered the problem was the ceramic was broken and chipped. It's a whole process as you have to take apart the caliper and completely re-bleed the system. This kits comes with all the new o-rings you need to rebuild the caliper like new. Fast-forward over a year and now having the same issues with the back calipers: broken ceramic piston. Came here to purchased the same resin set. Best part is there is no ceramic to break. Not sure how well the resin pistons will hold up "long term" but I've been riding the front set for over a year now. ### ⭐⭐⭐⭐⭐ Review *by O***R on 9 May 2023* I needed to replace the pistons in my GRX disc caliper as one cracked after pushing my brakes past their limit on a very tough (read dumb) ride. The caliper disassembly and rebuild was straightforward with the pistons and piston seals. I did not use the kit’s smaller o-rings. After a couple of fluid bleeds, the brakes pumped up nicely and my original lever feel has been restored. I do not see any leaks or reason to believe they will start leaking. Although my measurements show the EXNAVI pistons as 0.01mm larger than the OEM version, be mindful that 0.01 is within the error of this type of measurement tool and technique. I run a machine shop and have done a ton of mechanical repairs in all sorts of machines over the years and had no qualms about dropping these replacement pistons in. Although I can’t specifically pinpoint the exact material these are made of, it does appear to be a ceramic. I would even say that the surface finish appears to be smoother than the OEM pistons - perhaps that’s a good thing? Overall, If I ever need to repair another caliper, I would have no hesitation to buy this kit again. ### ⭐⭐⭐⭐⭐ Review *by D***N on 11 April 2025* Look like a good replacement. Purchased on accednt. So sent back. ## Frequently Bought Together - OD21.9*H8.8 bicycle hydraulic brake caliper piston oil leakage repair kit upgrade replacement Shimano ceramic double piston suitable for M675 M785 M7000 M7100 M8000 M8100 M9000 M9020 M9100 brakes - SHIMANO BRBX Pads + spg Alloy Back Resin L05A w/Fin Black one Size - SHIMANO Mineral Oil --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.vu/products/646464652-bicycle-hydraulic-brake-caliper-piston-oil-leakage-repair-parts-maintenance](https://www.desertcart.vu/products/646464652-bicycle-hydraulic-brake-caliper-piston-oil-leakage-repair-parts-maintenance) --- *Product available on Desertcart Vanuatu* *Store origin: VU* *Last updated: 2026-05-13*