85103803-1 Brake Disc Heavy Duty for commercial vehicles

Specification sheet

Fitment & verification

How to identify the correct unit: locate the reference number stamped on your original component or in the vehicle parts catalogue, then cross-check it against the number below before ordering. Trim and market variants exist for many applications, so the short check is worth the minute before checkout.

How to identify & confirm fitment in 4 steps

1. Locate the OE / reference number on your old part or in the vehicle parts catalogue.
2. Match it to 85103803-1 shown on this page.
3. Send your VIN and engine code plate so our team runs an exact-fit check.
4. Receive fitment confirmation before we dispatch your order.

Cross-reference coverage for brake disc fitment is listed above; confirm your VIN before ordering.

Overview & context

A direct-fit compatible replacement referenced by 85103803-1 for the applications listed in the fitment block.

Build & materials

Built to the original equipment drawing, the Brake Disc follows the same inspection checkpoints as the reference sample. Tolerances that affect installation are held to the drawing rather than adjusted on the bench.

• Surface treated to resist corrosion in road and workshop conditions.
• Dimensional check against the reference sample before packing.

Material and build choices answer the most common brake disc replacement and brake disc guide questions from workshop buyers.

Application & fitment

The fitment block above lists the markets and model families this reference is stocked for, so buyers can match demand without re-checking every listing.

Technical notes

Application context. On Volvo FH and Renault Magnum tractors, a deteriorating 434 mm rotor announces itself through brake judder at motorway speeds, a spongy pedal after long descents, and grooves deep enough to feather new pads within days. The disc is the load-bearing friction member of the axle's air disc brake: the caliper clamps both vented faces, and heat generated by forty tonnes slows only as fast as the rotor can shed it. A casting worn past its listed minimum overheats, heat-checks and eventually threatens caliper and hub components.

Deep dive. Handle this disc as the heavy component it is, with a helper or lift assist, since listings put its section in the heavy truck class. It mounts front or rear according to the axle, over a ten-stud hub, and references in this family list internally vented construction and a matching centring bore; clean the hub mating face of rust before fitting. Check the caliper carrier bolts, pad slides and hub bearing play while the wheel is off, then torque studs to specification and bed pads gently away from the depot.

Deep dive. Track thickness at every scheduled brake check: new thickness is listed at 45 mm with minimum figures quoted around 41 mm for this family, so usable wear is modest by design. Measure both faces at opposite points, record per wheel, and investigate any side-to-side gap of more than a fraction of a millimetre. Look for heat spotting, edge lips and corrosion on the hat. Tractors and trailers working quarry or timber routes need shorter inspection intervals, because abrasive dust accelerates wear beyond the fleet average.

Application context. This heavy-duty pattern crosses to Volvo 85103803, 21575071, 85110496, Renault 5001864498 and 7421575117, serving Volvo FH and FM and Renault Magnum and Premium applications. Distinguish heavy truck discs from passenger-car items on section thickness, weight and vented vane design; the material declaration matters too, with G3000/HT250-class iron, hardness around 187-241 HB and minimum tensile near 220 MPa being the datasheet norm. A lighter, unbranded casting at the same nominal size is a false economy on a 40-tonne axle set.

Technical background. Supplier datasheets for this reference advertise ECE R90 approval and production under ISO/TS 16949 and ISO 9001 quality systems, alongside microstructure specs of type A graphite, 95 percent minimum pearlite and 100 percent balancing and crack detection before shipment. These are exactly the claims a buyer should verify by asking for the certificate numbers rather than accepting logos on a web page. For EU fleet tenders, an R90 approval number on the box is the practical checkpoint; for plant audits, the ISO registration scope shows what was actually certified.

Technical background. The core customers are long-haul fleet operators running Volvo FH12, FH16 and FM series tractors and Renault Magnum DXi units, plus bus operators whose Volvo B-series chassis share the reference. Distributors serving mixed Volvo and Renault yards like this number because one line covers both marques. Buyers typically order in axle sets with pads, ask for pallet quantities, and judge a supplier on dimensional consistency between batches, documentation quality and the ability to keep the reference in continuous stock through peak season.

Field note. Heavy commercial discs of this class are always sold into a wheel-end system, so plan the surrounding parts at order time: pads for the same axle in matched sets, hub seals and bearing kits when end-play is out of spec, and caliper guide hardware that the stripped-down disc box never includes. On multi-axle trucks and trailers, replace disc and pad sets axle-by-axle, never corner-by-corner, so braking balance stays even. Fleets should also audit dust shields and stud condition during the change, since stone-damaged shields and stretched studs are the two quiet killers of a newly fitted heavy disc.

Application context. Heavy-duty castings live or die by handling. Ship palletized with every disc sleeved separately, edge protection on the hat, and gross weights marked so yards use mechanical lifting rather than backs; a dropped 30-kilogram-class vented disc can crack invisibly and fail months later. Store on racks indoors, off damp floors, and keep the rust-preventive coating untouched until the bay, because heavy-vehicle stock often sits in depots for years. Rotate stock by casting date, and reject any box showing forklift punctures: the damage pattern under a punctured corner routinely reaches the friction face.

Field note. Wheel-end prep on a commercial axle is a measured process. Clean the hub mounting face and centering seat to bare metal, fit the disc with lifting gear, and verify lateral runout with a dial indicator before the wheel returns; a hub-piloted seat with burrs ruins an otherwise perfect casting. Torque the wheel studs in a crossed sequence with a calibrated wrench and re-check after the first run, since heavy-vehicle joints settle. Confirm caliper piston retraction and pad slide geometry, and blow grit out of the vanes. Log the thickness reading taken at fitment as the baseline for wear tracking.

Technical background. Duty environment drives replacement economics on this axle class. Municipal and construction trucks in salted winter regions usually lose discs to corrosion around the hat and stud bores before friction wear, so coated-hat supply is worth specifying there. Mountain-refuse and regional-haul duty concentrates heat on descents, making the stamped minimum thickness a non-negotiable retirement point and pad formulation a shared decision. Tropical depots add a storage problem: humidity pits bare faces in months, so sealed packaging and first-in, first-out rotation protect the investment. Either way, thickness should be logged at every scheduled service.

Field note. Batch documentation is where a heavy-disc purchase is won or lost. Contract for HT250/G3000-class grey iron with heat-number traceability and a declared hardness band, plus per-unit records for dimensional inspection, crack detection, and dynamic balance, the trio serious truck foundries run on every casting. On arrival, sample each lot for thickness, bore and hole pattern, hardness, and surface finish, and retain samples per batch. The -1 suffix suggests a revision or variant level, so reconcile the suffix in the order against the drawing revision and the marking on the delivered hat before pallets are accepted into stock.

Field note. The suffix -1 is itself the trap. Variant-level designations like this usually mark a dimensional or application revision, and commercial-vehicle catalogs contain several visually identical vented discs that differ in centering diameter, overall height, or stud circle while sharing a bolt count. Buying on a photograph or a partial number cross-reference puts the wrong disc on a loaded axle. Before committing a fleet order, measure the hub's centering bore, PCD, and disc height on the vehicle, compare the minimum-thickness stamp against the axle's rated wear limit, and require the supplier to confirm the exact casting revision in writing.

Supply note. Datasheets for this reference claim ECE R90 approval and production under ISO/TS 16949 and ISO 9001 quality systems.

Supply note. Dimensions: 434 mm outer diameter, 45 mm thickness, internally vented; minimum thickness listed around 41 mm for this family.

Supply note. Cross-references: Volvo 85103803, 85110496 and 21575071; Renault Trucks 5001864498 and 7421575117.

Supply note. Applications: Volvo FH12, FH16, FM9, FM12, FL/FE and B-series buses; Renault Trucks Magnum DXi 12/13 and Premium II.

Supply note. Material specification from supplier datasheets: G3000/HT250 grey cast iron, hardness 187-241 HB, minimum tensile strength about 220 MPa.

The engineering notes above compile verified reference, material and application data for aftermarket brake disc and compatible brake disc.

Quality & testing

Inspection runs on an AQL sampling plan: incoming material, in-process checkpoints and a final release check are recorded on the batch sheet.

Warranty & support

12 Months limited warranty against manufacturing defects. Coverage applies to correctly installed units; keep the batch date code so any claim is processed against its inspection record. Disc thickness, minimum-thickness marking and runout questions are answered by our team before dispatch.

Why buyers pick Vidishi Auto

Brake Disc — Brake Disc. Supplied under Vidishi Auto with batch traceability and trade-grade packing; volume pricing and private-label options are available on request. Discs are supplied for car, light-truck and commercial-vehicle brake programs in solid, vented, drilled and slotted patterns.

Logistics & packing

We ship worldwide to distributors and garages from China, Dongguan. Each Brake Disc is packed in a single-unit export carton. Discs ship stacked with separator sheets in export cartons to protect the friction surface. Tracked air or sea freight is arranged per order volume.

Bulk quantities of brake disc supplier and brake disc bulk order ship in mixed containers from China, Dongguan.

Catalog & cross-reference

Catalog numbering for this Brake Disc: the primary reference is 85103803-1. When a supplier catalog lists superseded or regional formats, match on the numeric core of the code rather than the prefix, then confirm the physical fit.

Catalog cross-references for brake disc catalog resolve to 85103803-1.

Frequently asked questions

Further brake rotor questions are answered by the trade desk within one business day.

Compliance disclaimer

Vidishi Auto is an independent supplier. This is an aftermarket compatible replacement, not a genuine OEM part. Brand names are trademarks of their respective owners and are used only to identify fitment.

Wholesale & support

Wholesale terms are quoted per market: volume breaks, mixed-SKU containers and private-label options are all handled by the trade desk. Bolt-pattern, centre-bore and hub-height sheets are available on request.

Trade desk replies with quotation, MOQ and lead time in one business day.

Enquiries about wholesale brake disc and brake disc price receive quotations within one business day.

Machining & runout checks

Disc condition at fitment decides braking performance; the checks below are confirmed with every order.

Installation and service notes for oem brake disc, brake disc warping and brake disc brake rotor are confirmed by our technical team before dispatch.

• Pre-dispatch checks: the OE / reference number is matched against your old part before packing.
• Friction-face parallelism and runout are checked against the reference sample before packing.

Workshop teams comparing brake disc replacement cost, brake disc cross reference and how to confirm brake disc fitment receive the pre-dispatch checklist with the quotation.

• Minimum-thickness marking and discard-limit data are confirmed with the quotation on request.

Installation and service notes for quality hot, 430mm brake disc and t-drive brake rotor are confirmed by our technical team before dispatch.

• Hub bore, bolt pattern and overall height are matched to your old disc before dispatch.

Workshop teams comparing bus brake disc receive the pre-dispatch checklist with the quotation.

Bed-in & service notes

Disc service life depends on the bed-in procedure; the notes below are supplied with every order.

• Configuration checks: the supplied configuration is confirmed against your order before dispatch.

Configuration and service notes for real carbon brake disc, disc brake disc and brake discs change are confirmed by our technical team before dispatch.

• Bed-in guidance is supplied with the quotation on request.
• Discard-limit thickness data is confirmed against your workshop specification.

Workshop teams comparing what is a brake disc, high quality and g3000 brake disc receive the configuration checklist with the quotation.

• Pair replacement is recommended where the listing supplies a single disc.

Configuration and service notes for volvo heavy duty rotor and cast iron brake rotor are confirmed by our technical team before dispatch.

Surface pattern options

Solid, vented, drilled and slotted patterns are stocked by reference; the options below are confirmed before dispatch.

• Reference checks: the OE / reference number is matched against your old part before packing.

Application data for brake discs, sram centerline 160mm rotor center lock brake disc rotor and brake disc vs rotor is confirmed against your specification before dispatch.

• Surface pattern and vent design follow the published listing.
• Coating and anti-corrosion treatment scope is confirmed with the quotation.

Engineering checks behind the best brake disc for aftermarket, hot sale and oe brake disc supply are completed before packing.

• Friction faces are oil-film protected before export packing.

Application data for brake disc for mercedes-benz is confirmed against your specification before dispatch.