Clutch Slave Cylinder 8-97039704-0 8970397040 For ISUZU TFR54 TFS54 4JA1 (1993–2011) — Ø20.6mm Bore, Cast Iron, 98mm Mounting, OEM Genuine & Aftermarket

ISUZU's official parts catalogue describes 8970397040 as a genuine ISUZU part ("CYLINDER SLAVE"), stating it is "exactly the same as the one mounted at the factory when the vehicle was new", with a reference price of €78.99 (ex-tax). The cylinder is manufactured from cast iron (Fonte / Litina), with a Ø20.6 mm piston bore, 98 mm mounting hole distance, and 1 × M10×1.0 connection thread. Reference weight is 0.97 kg (A.B.S.) / 0.83 kg (Blue Print), and it is confirmed as RHD (Right-Hand Drive) compatible by Australian ISUZU specialist Brettstruck.

• OEM Genuine Status Verified: 8970397040 is confirmed by parts-isuzu.com as a genuine ISUZU part ("exactly the same as factory"), with reference price €78.99 ex-tax.
• Bore Diameter Verified: Ø20.6 mm — confirmed by Oscaro (A.B.S. 71757: "Diametre du piston : 20,6 mm"), LPR 3127 ("Piston Diameter [mm]: 20,6"), and A.B.S. 71757 ("Průměr: 20,6").
• Mounting & Thread Verified: 98 mm mounting hole distance, 2 mounting holes, 1 × M10×1.0 thread — confirmed by A.B.S. 71757 ("Distance entre les boulons : 98 mm", "1x M10x1.0") and LPR 3127 ("Distance of mounting bores [mm]: 98").
• Material Verified: Cast Iron (Fonte / Litina) — confirmed by A.B.S. 71757 ("Materiau : Fonte") and LPR 3127 ("Material: Cast Iron").
• Weight Verified: 0.97 kg (A.B.S. 71757) / 0.83 kg (Blue Print ADZ93609) — consistent range depending on brand and packaging.
• Drive Configuration Verified: RHD (Right-Hand Drive) — confirmed by Brettstruck CO24020 ("Position | RHD").
• Vehicle & Engine Coverage Verified: TFR54 (Jan 88–Dec 96, 2.5L), TFS54 (Jan 97–Jan 11, 4JA1), TFR/TFS 4JA1 (Apr 98–Oct 01), TFR/TFS 4JB1, 4JG2, 6VD1, C22NE, 20SE, 4ZE1, OPEL Campo (Jan 90–Dec 95) — confirmed by Brettstruck CO24020 application data.
• Cross-Reference Density Verified: 8970397040, 8-97039-704-0, 8-97039704-0, 8943891930, 8944177051, 8944741230, 94474123, 97039704, 94389193, 8979445133, 160720004 (JMC) are consistently grouped across ISUZU, General Motors, Opel, Vauxhall, and JMC catalogs.
• Brand Cross-Reference Verified: Blue Print ADZ93609, A.B.S. 71757, LPR 3127, BREMBO E 59 014, TRW PJF148, JAPANPARTS CY-998, JAPKO 85998, KAVO PARTS CCS-8006, AISIN RG-012, Seiken SRG350 — all confirmed as aftermarket equivalents.

• Clutch pedal does not return after shifting, and the vehicle starts to move on its own: The clutch is not fully disengaged — a classic sign of a failing slave cylinder or air in the hydraulic circuit.
• Difficulty shifting gears / gear clash: Insufficient hydraulic pressure prevents full clutch release, forcing the driver to press the pedal almost to the floor to shift.
• Clutch pedal feels spongy or soft, with a low engagement point: Internal seal failure or air ingress prevents the slave cylinder from building full pressure.
• Visible clutch fluid leak at the slave cylinder body or pushrod end: External seal failure is a leading cause of slave cylinder replacement on high-mileage TFR54 trucks.
• Clutch drag / "dragging" clutch: If the slave cylinder cannot fully release the pressure plate, the clutch drags, causing hard shifting and accelerated clutch wear.
• Fluid level dropping in the clutch reservoir without an obvious external leak: Internal seal bypass can allow fluid to escape into the pushrod boot area or the bellhousing.

• RHD vs. LHD: Brettstruck explicitly lists this cylinder for RHD (Right-Hand Drive) applications. While the TFR/TFS platform is widely sold in both configurations, LHD vehicles may use a different hydraulic line routing or mounting angle. Confirm the vehicle's steering configuration before ordering.
• Bore diameter tolerance: 20.6 mm is the dominant specification. 20.5 mm (JAPANPARTS/JAPKO) is a measurement tolerance, not a functionally different part. Do not reject a 20.5 mm-marked unit solely on that basis — but verify against the original cylinder's bore if precision matching is required.
• JMC cross-brand coverage: The 160720004 JMC OEM reference confirms this cylinder also serves JMC 1020/1021/1023 pickups (493ZQ engine family). This makes it a cross-brand SKU for distributors serving both ISUZU and JMC light truck populations.
• Genuine vs. aftermarket: This cylinder is available as ISUZU Genuine (~€78.99 ex-tax) and as aftermarket equivalents from Blue Print, A.B.S., LPR, BREMBO, and others. Confirm the buyer's requirement for OEM authenticity versus cost-effective aftermarket supply.

1. Confirm the required part first: Verify the original slave cylinder's bore diameter (Ø20.6 mm), mounting hole distance (98 mm), and connection thread (M10×1.0). Confirm the vehicle's drive configuration (RHD/LHD).
2. Safety first: Park on level ground, engage the parking brake, and chock the wheels. Do not open the hydraulic circuit while under pressure.
3. Disconnect the hydraulic line: Place a drain pan underneath, disconnect the fluid line from the slave cylinder, and plug the line immediately to prevent contamination.
4. Remove the mounting bolts: Unbolt the slave cylinder from the transmission bellhousing. Note the orientation of the pushrod and any return spring.
5. Compare new and original: Verify that the replacement has the same 20.6 mm bore, pushrod length, and mounting flange orientation as the original unit.
6. Bench-bleed the slave cylinder (recommended): Fill the cylinder with clean clutch fluid and bleed it on the bench before installation to reduce in-vehicle bleeding time.
7. Install the new cylinder: Position the 8-97039704-0 cylinder on the transmission, insert the mounting bolts, and torque to the workshop manual specification.
8. Reconnect the hydraulic line: Connect the fluid line to the M10×1.0 outlet and tighten without over-torquing.
9. Bleed the clutch system: Fill the clutch master cylinder reservoir with the specified fluid and bleed until clear, bubble-free fluid flows from the bleeder screw. Air in the circuit is the leading cause of post-replacement clutch drag.
10. Test operation: With the engine running, depress the clutch pedal and verify smooth gear engagement in all gears. The pedal should return fully and the vehicle should not creep when a gear is selected with the clutch depressed.

• Inspect clutch fluid level at every engine oil change — a dropping level indicates a leak that requires immediate attention.
• Flush clutch fluid every 2 years or according to ISUZU schedule — degraded fluid accelerates seal wear in both the master and slave cylinders.
• Check for leaks at the slave cylinder body, bleeder screw, and hydraulic line fitting during routine inspection.
• Replace the slave cylinder at the first sign of a spongy pedal or external leak — do not "top up and monitor" a known-failing hydraulic component on a commercial pickup.

• Standard packing: Neutral box / color box / customer-branded packaging; wooden case or pallet available for bulk export orders. Pack quantity: 1 PCS.
• Package contents: 1 × Clutch Slave Cylinder. Pushrod, bleeder screw, mounting hardware, and clutch fluid are not included unless explicitly stated — confirm exact package contents at inquiry.
• Set options: Cylinder only (standard) / cylinder + pushrod kit (subject to availability) — specify at inquiry.
• Suitable for: ISUZU TFR54/TFS54 clutch repair shops, Opel Campo / JMC 1020 service providers, light commercial fleet maintenance departments, spare parts distributors, and export wholesalers serving Southeast Asia, the Middle East, Africa, and Latin America.
• Related parts available: Clutch master cylinder, clutch disc, pressure plate, release bearing, clutch fluid, and complete TFR54/TFS54 clutch hydraulic service kits.