TOYOTA/LEXUS 1301121050 CYLINDER KIT
Product Specifications
| TOYOTA/LEXUS | 1301121050 |
| TOYOTA/LEXUS | 1301121120 |
| TOYOTA/LEXUS | 1301121041 |
| TOYOTA/LEXUS | 1301121040 |
The CYLINDER KIT is a complete repair kit containing all the sealing, dust protection, and hardware components required to overhaul a disc brake caliper in-situ without replacing the caliper body — restoring the caliper's hydraulic integrity and mechanical freedom of movement to as-new condition at a fraction of the cost of complete caliper replacement. A standard caliper repair kit comprises the piston seal — a square-section EPDM rubber ring seated in a machined groove in the cylinder bore that seals hydraulic pressure between the piston and bore and retracts the piston by a precise amount when pressure is released to provide the running clearance between pad and disc — the piston dust boot that excludes road contamination from the piston-to-bore interface, slide pin rubber boots that seal the slide pin bores from road salt and moisture, slide pins themselves where worn, and anti-squeal shims and hardware clips for the pad mounting. On rear calipers with integrated electric parking brake mechanisms, the kit additionally includes the thread seal for the EPB motor shaft and any seals for the parking brake spindle bore.
This unit — TOYOTA/LEXUS 1301121050 — is manufactured to OEM-equivalent specifications: piston seal cross-section diameter and compound hardness, dust boot inner and outer diameter and profile geometry, slide pin boot profile and material, slide pin diameter and surface finish tolerance, and all hardware dimensions are matched to the original caliper's specifications. Supplied as a complete kit with all components required for a full caliper overhaul. Available wholesale from 8.85 USD, MOQ
Caliper seal kits are the correct repair intervention when a caliper shows brake fluid weeping from the piston area or dust boot, a piston that does not retract correctly after pad compression, or a caliper that binds on its slide pins causing uneven pad wear — provided the caliper bore and piston surfaces are confirmed free of corrosion pitting and scoring that would prevent the new seals from maintaining hydraulic integrity. A cylinder bore with deep pitting or a piston with surface corrosion cannot be resealed reliably and requires complete caliper replacement; always inspect bore and piston condition before committing to a seal kit repair.
- Bleed the brake circuit and retract the piston fully before removing the caliper from the vehicle — open the bleed nipple slightly before pushing the piston back to allow the displaced fluid to exit rather than being forced back through the ABS modulator; fluid forced through the ABS modulator dislodges valve seat deposits that can block the modulator's solenoid valves, causing ABS and ESC fault codes that require specialist flushing to resolve.
- Inspect the caliper bore and piston surface thoroughly under good lighting before proceeding with the seal kit repair — insert the removed piston into the bore and rotate it while pushing to feel for rough spots; use a bore light to examine the bore wall for pitting, scoring, or deep corrosion marks; any pitting deeper than 0.1 mm or scoring visible to the naked eye means the caliper body cannot be reliably resealed and must be replaced — continuing with the seal kit on a pitted bore produces a repeat leak within a short period.
- Clean the bore, piston, and all seal grooves with dedicated brake system cleaner — never use petroleum-based solvents, brake cleaner containing petroleum distillates, or compressed air to dry a cleaned bore as these leave residues that degrade the new EPDM seals; use only isopropyl alcohol or dedicated brake component cleaner and allow to air dry completely before fitting new seals.
- Lubricate the new piston seal and bore wall with clean brake fluid of the correct specification before assembly — apply a thin film of brake fluid to the seal groove and seal outer surface only; never use petroleum-based grease, silicone grease, or copper grease near any brake hydraulic component; use the brake assembly lubricant supplied with the kit for slide pin bores and boot seating surfaces only.
- Install the new piston seal in its groove without twisting — the square-section seal must sit flat in its groove with no spiral twist; a twisted seal produces inconsistent rollback behaviour, causing either brake drag from insufficient piston retraction or excessive running clearance from over-retraction; press the seal into the groove uniformly around the full circumference and confirm it sits flush before inserting the piston.
- Install the new CYLINDER KIT (TOYOTA/LEXUS 1301121050), refit the caliper, bleed the brake circuit until no air bubbles are present at the bleed nipple, pump the brake pedal firmly to seat the piston against the new pads, confirm pedal height and firmness are correct, check for fluid leaks at the caliper and bleed nipple under firm pedal pressure, and road test with several progressive stops from moderate speed before returning the vehicle to service.
| Part | Reason for Combined Replacement |
|---|---|
| Brake Pads Axle set, OEM ref. varies | Caliper overhaul requires retracting the piston fully to access the bore — this is the definitive opportunity to inspect pad thickness and replace the pads if they are at or approaching minimum thickness. Fitting a newly overhauled caliper with worn pads means the piston will need to be retracted again within a short service interval, unnecessarily stressing the new seals. Always replace pads simultaneously with any caliper seal kit service. |
| Brake Fluid DOT 4 or DOT 5.1 per OEM specification | Caliper overhaul requires opening the brake hydraulic circuit and bleeding the caliper, making this the mandatory time to assess brake fluid condition. Moisture-saturated fluid with a high wet boiling point depression degrades the new EPDM piston seal by promoting corrosion at the piston-to-bore interface. Replacing the brake fluid simultaneously with the seal kit service maximises the service life of the new seals and restores the circuit's full high-temperature braking capacity. |
| Brake Disc OEM ref. varies by axle position | A caliper that has been dragging due to a seized piston or slide pins will have overheated the brake disc, causing heat stress cracking, surface hot spots, and thickness variation. A disc that has been subjected to extended drag overload should be measured for runout and minimum thickness and replaced if either measurement is out of specification — fitting new pads and a freshly overhauled caliper to an overheated disc produces immediate brake judder and uneven pad transfer. |