VAG/PORSCHE 059109521E ADJUSTER
Product Specifications
Product quality
OEM Equivalent Grade
3000 sold
Wholesale price USD
$0.84
Wholesale price CNY
¥5.82
bolt MOQ (Minimal order)
400 pcs
local_shipping Production time
60 days
package_2 Shipping Weight:
0.02 kg
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Application (cross references) 4
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| VAG/PORSCHE | 059109521E |
| VAG/PORSCHE | 059109521B |
| VAG/PORSCHE | 059109521C |
| VAG/PORSCHE | 0640066 |
Overview & Operating Principle
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The ADJUSTER is the drum brake shoe adjuster — a threaded spreader mechanism positioned between the lower ends of the two brake shoes in a drum brake assembly that maintains the correct running clearance between the shoe lining surfaces and the brake drum inner diameter as the lining material wears progressively during service. The adjuster consists of a threaded rod with right-hand thread at one end and left-hand thread at the other, engaging two end caps whose outer faces bear against the lower shoe webs; a toothed star wheel or knurled adjuster body between the end caps provides the means for rotating the rod to extend or retract the overall adjuster length, changing the distance between the shoe lower ends and therefore the shoe-to-drum clearance. On manually adjusted systems a screwdriver or dedicated adjuster tool is inserted through the adjuster slot in the drum backing plate to rotate the star wheel until the drum slides over the shoes with light drag, confirming the correct clearance is achieved. On self-adjusting systems — now standard on all modern vehicles — the adjuster is connected to the handbrake lever or to a spring-loaded lever that rotates the star wheel automatically in response to the shoe-to-drum clearance becoming excessive: when the shoe lining wears sufficiently that the shoe travel during parking brake application exceeds a threshold, the self-adjuster lever advances the star wheel by one tooth, extending the adjuster length and reducing the shoe-to-drum clearance to the designed value without technician intervention.
This unit — VAG/PORSCHE 059109521E — is manufactured to OEM-equivalent specifications: adjuster body thread pitch and hand, end cap bearing face diameter and geometry for the shoe web contact, star wheel tooth count and pitch for the correct adjustment increment per tooth, overall minimum and maximum length range for the specific drum diameter and shoe thickness combination, and material — typically chromium-plated or zinc-plated steel — for corrosion resistance in the wet brake environment are matched to the original part. Supplied as a complete adjuster assembly. Available wholesale from 0.84 USD, MOQ 400 pcs, production lead time 60 days.
Drum brake adjusters fail through thread corrosion seizure from road salt and moisture that prevents the adjuster from extending under self-adjuster lever action, causing the shoe-to-drum clearance to grow progressively as the lining wears — the pedal travel increases noticeably as the clearance grows, and the parking brake effectiveness reduces; through star wheel tooth stripping from overtightening during manual adjustment that prevents any further adjustment; and through end cap bearing face wear that allows the adjuster to tilt in the shoe web pocket rather than transferring load evenly, eventually causing the adjuster body to crack under the asymmetric load.
Symptoms & Diagnostics
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Excessive brake pedal travel before braking effect is felt — the pedal travels significantly further than normal before the shoes contact the drum, combined with reduced braking effort at the first pedal application — the adjuster has seized in its current position and has not compensated for shoe lining wear; the excessive clearance between the worn shoes and the drum requires more pedal travel to take up before the shoes contact; confirm by observing whether the pedal travel reduces after several firm pedal applications — normal drum brakes partially self-adjust under use, but a seized adjuster produces no improvement regardless of the number of applications.
Parking brake lever that requires more strokes to fully apply or that fails the parking brake effectiveness test — the lever travel is excessive and the brake cannot hold the vehicle on a gradient that it previously held with one or two clicks — the shoe-to-drum clearance has grown from adjuster seizure; the parking brake cable takes up the clearance through additional lever travel, but the available cable travel is consumed by the excessive clearance before the shoe reaches the drum with adequate contact pressure; the parking brake fault is a consequence of the adjuster fault.
Adjuster star wheel that will not turn in either direction when accessed through the backing plate slot — requires excessive tool force that risks stripping the star wheel teeth — the adjuster thread is seized with corrosion; apply penetrating oil through the backing plate slot and allow extended soak time before attempting to turn again; an adjuster that cannot be freed by penetrating oil and light lever action requires removal and replacement — continuing to force a seized star wheel strips the teeth and leaves an adjuster that is permanently fixed at its current length.
Rattling noise from the drum brake area during light braking or when driving over rough surfaces — a metallic rattle that reduces when the brake is lightly applied and disappears under firm brake pressure — the adjuster has backed off from its correct extension length and the shoe-to-drum clearance has increased to the point where the shoes rattle in the drum on road vibration; the rattle reduces when the brake is applied because the shoes contact the drum and are held against the backing plate; confirm by removing the drum and inspecting the adjuster's extension length against the OEM specification.
New brake shoes fitted but the drum cannot be reinstalled over them — the new shoes are too wide for the drum even with the adjuster retracted to its minimum length — the adjuster was not wound back to its minimum extension before fitting the new shoes; retract the adjuster fully by rotating the star wheel in the contracting direction before attempting to fit the drum over new shoes; never force the drum over un-retracted shoes as this can crack the drum or damage the new shoe linings.
Adjuster end cap bearing face visibly worn — the flat bearing face that contacts the shoe web shows a worn groove or rocking wear — on inspection when the drum is removed — a worn bearing face allows the adjuster to tilt under the shoe spreading load, concentrating the load on one edge of the contact and progressively cracking the adjuster body at the loaded edge; replace the adjuster assembly when any end cap bearing face wear is visible.
Logistics & Customs
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International HS Code
8708.30
EAEU Customs Code (TN VED)
8708 30 910 0
Typical Net Weight
0.02 kg
Country of Manufacture
China
Standard MOQ
400 pcs
Production Lead Time
60 days
Always verify the exact 8-digit or 10-digit subheading with your customs broker for the destination country, as tariff schedules and duty rates vary by jurisdiction.
Installation Tips
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- Note the adjuster's orientation before removal — it is handed left and right and may have a directional thread — drum brake adjusters on many vehicles have right-hand thread on one end and left-hand thread on the other, or are asymmetrically designed for the leading and trailing shoe positions; a reversal of left-right handedness installs the star wheel on the wrong side for the self-adjuster lever to contact, preventing automatic adjustment from the first use; confirm the correct orientation from the vehicle service data or by comparing the new adjuster to the removed unit before installation.
- Replace adjusters in axle pairs simultaneously — both rear drum brake adjusters accumulate the same corrosion and wear from identical environmental exposure; if one adjuster has seized, the opposite is at the same corrosion stage and will seize within a short interval; replacing both during a single drum removal operation ensures symmetric pedal feel and parking brake effectiveness on both rear wheels and eliminates a repeat drum removal within a short mileage.
- Apply copper-based anti-seize compound to the adjuster thread and to the end cap bearing face contact zones before installation — the anti-seize prevents the corrosion-induced thread seizure that caused the original adjuster failure; apply sparingly to the thread — do not pack the thread excessively as surplus compound can be displaced into the shoe lining contact zone and contaminate the lining; apply a thin film to the bearing face contact surfaces where the end caps bear against the shoe webs.
- Set the adjuster to approximately the correct extension length before fitting the shoes — measure the drum internal diameter with a drum micrometer or vernier calliper and set the adjuster extension to approximately 1–1.5 mm less than the drum diameter across the shoe faces; this initial setting allows the drum to be installed without excessive force while providing sufficient shoe-to-drum proximity for the self-adjuster to achieve correct clearance during the first brake application cycle.
- After drum installation, pump the brake pedal 10–15 times and apply the parking brake firmly 5 times to cycle the self-adjuster — on self-adjusting systems the self-adjuster lever advances the star wheel only during brake application; the initial adjustment cycles seat the shoes against the drum and advance the adjuster to the correct clearance; confirm the pedal feel is firm after the adjustment cycles — a pedal that remains long after 15 applications indicates the self-adjuster is not functioning and requires investigation.
- Install the new ADJUSTER (VAG/PORSCHE 059109521E) on both sides of the axle simultaneously, perform the initial adjustment cycling procedure, confirm firm brake pedal feel, test parking brake effectiveness on a gradient, confirm no brake drag by spinning the drum by hand — the drum should rotate with light but perceptible resistance; zero resistance indicates the shoes are not correctly adjusted; heavy resistance indicates the shoes are binding and the adjuster requires backing off — before returning the vehicle to service.
Tools: drum brake adjuster tool or flat screwdriver for star wheel access through backing plate slot, drum micrometer or vernier calliper for diameter measurement, copper anti-seize compound, brake spring tool for shoe retraction springs.
Frequently Asked Questions
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How can a seized drum brake adjuster be identified without removing the drum?
Three in-situ tests indicate a seized adjuster before drum removal. First, excessive pedal travel that does not reduce after 5–10 firm pedal applications confirms the adjuster is not self-adjusting — a functional self-adjuster compensates for clearance after each application. Second, access the adjuster star wheel through the backing plate slot and attempt rotation with a flat screwdriver — a serviceable adjuster turns freely in both directions; a seized one requires disproportionate force or does not move at all. Third, measure parking brake lever travel — count the number of clicks to achieve firm parking brake application; more than 5–7 clicks on a system designed for 3–4 confirms excessive shoe clearance consistent with a seized adjuster. Drum removal confirms the diagnosis and allows the adjuster condition to be assessed directly. ok.parts supplies drum brake adjusters at wholesale MOQ from 0.84 USD per unit.
Is drum brake shoe replacement always required when the adjuster is replaced?
Brake shoe replacement is not always required simultaneously with adjuster replacement — the decision depends on remaining lining thickness. With the drum removed for adjuster access, measure the brake shoe lining thickness at the thinnest point; the OEM minimum lining thickness is typically 1.5–2.0 mm; shoes above this threshold are serviceable and can be reused with the new adjuster. However, a seized adjuster that has allowed the lining to wear unevenly — thicker at the top and thinner at the bottom, or vice versa — has a lining profile that will not mate correctly with the drum surface on initial bedding after adjuster replacement; inspect the lining wear pattern and replace the shoes if uneven wear exceeds 1 mm across the lining face. Always replace shoes as an axle pair — never replace only one shoe or only one wheel's shoes.
How does the OEM-equivalent aftermarket unit compare to the genuine OEM part?
OEM-equivalent units in this catalogue replicate the current OEM design geometry and material specification. Quality is verified against OEM cross-reference data. When ordering in bulk, confirm with our team that the specification matches the latest OEM revision for your application.
Is white-label or custom packaging available for wholesale orders?
Yes. ok.parts works directly with the manufacturing facility and can accommodate neutral white-label packaging or fully branded packaging with your company logo, part numbers, and barcode. Minimum order quantities and lead times for custom packaging may differ from standard stock. Contact the team via the inquiry form to discuss your specific requirements.
Frequently Replaced Together
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| Part | Reason for Combined Replacement |
|---|---|
| Brake Shoes Axle pair — OEM ref. varies by drum diameter | A seized adjuster that has not been compensating for lining wear has allowed the shoes to wear beyond the point where they would normally trigger a service — the adjuster failure masks the lining wear by maintaining the pedal feel through cable stretch rather than through correct shoe clearance. Measure the lining thickness when the adjuster is replaced; shoes that are at or below the minimum thickness require simultaneous replacement; shoes with uneven wear from incorrect shoe geometry from the adjuster failure also require replacement to restore correct contact pattern with the drum. |
| Brake Drum OEM ref. varies by axle and vehicle | A drum that has been in service with a seized adjuster may have developed an uneven wear groove inside its bore from the shoe that was pressing against it with a fixed geometry rather than the self-adjusting geometry. Measure the drum internal diameter at multiple points across its width and compare against the OEM maximum diameter — a drum worn beyond its maximum serviceable diameter is unsafe and must be replaced; a drum with a wear groove deeper than 0.3 mm requires replacement or machining to restore a flat contact surface for the new shoe lining. |
| Drum Brake Hardware Kit Return springs, hold-down springs, and pins | The drum brake return springs, hold-down springs, and retaining pins that are disturbed during adjuster replacement should be inspected and replaced where weakened from fatigue or corrosion. A return spring that has lost tension from heat cycling no longer returns the shoe promptly to its released position, maintaining residual shoe-to-drum contact that causes brake drag and accelerated lining wear. Including a complete hardware kit in every drum brake service ensures the complete mechanism operates with correct spring forces and that all corrosion-prone clips and pins are renewed at a single service operation. |