Removing and installing ABS control unit J104/ABS hydraulic unit N55, vehicles with 4-cyl. petrol engine — VW
Removing and installing ABS control unit J104/ABS hydraulic unit N55, vehicles with 4-cyl. petrol engine on VW: 34 steps.
Workshop procedure for VW — the exact step sequence and torque figures, straight from real workshop data.
🧭 Before you start
Fits: platform codes A32, A33
- Opens: brake fluid
Don't miss
- Ensure no brake fluid gets onto contacts.
- First, mark the two brake lines (A) and (B) coming from brake master cylinder.
- Mark and unscrew brake lines (1) to (4).
- Before installing holder of ABS hydraulic unit N55 on bracket, spray rubber dampers with silicone lubricantD 007 000 A2.
📋 Procedure
- Use to read code of ABS control unit J104 and note it.
- If vehicle has a coded radio, note radio code or, if necessary, request it.
- Remove engine cover 10Engine cover; Removing and installing engine cover.
- Disconnect battery Electrical system27Battery; Disconnecting and reconnecting battery.
- Remove charge air pipe 21Charge air system; Assembly overview - charge air system.
- Seal turbocharger openings with engine bung setVAS 6122.
- Unscrew nut (3), if present.
- Unclip heat shield (1) from plenum chamber bulkhead (arrow).
- Remove heat shield (1).
- Release connector from ABS control unit J104 in (direction of arrow) and pull it off.
- Apply brake pedal depressorV.A.G 1869/2.
- Pull caps off bleeder valves on left side.
- Connect bleed bottle bleed hose (1) to bleed valve of front left brake caliper.
- Open bleed valve.
- Connect bleed hose of bleed bottle (1) to bleed valve of rear left brake caliper.
- Open bleed valve.
- Depress brake pedal at least 60 mm using brake pedal depressorV.A.G 1869/2.
- Close front left and rear left bleeder valves.
- Place sufficiently lint-free cloths under ABS control unit J104 and ABS hydraulic unit N55. [Note: Ensure no brake fluid gets onto contacts.]
- First, mark the two brake lines (A) and (B) coming from brake master cylinder.
- Detach brake lines (A) and (B) from ABS hydraulic unit N55.
- Seal brake lines and threaded holes immediately using sealing plugs1H0 698 311 A or sealing plugs5Q0 698 311.
- Mark and unscrew brake lines (1) to (4).
- Seal brake lines and threaded holes immediately using sealing plugs1H0 698 311 A or sealing plugs5Q0 698 311.
- Turn hexagon fitting bolt out of retainer (arrow).
- Pull ABS hydraulic unit N55 together with ABS control unit J104 and side bracket out of rubber dampers of bracket in (direction of arrow).
- Turn ABS hydraulic unit N55 with ABS control unit J104 upside down.
- Unbolt bracket from ABS hydraulic unit N55 in engine compartment and remove it.
- Remove ABS hydraulic unit N55 together with ABS control unit J104. [Note: Remove sealing plugs from new hydraulic unit only when the corresponding brake line is to be fitted.If sealing plugs are removed too early from the hydraulic unit, brake fluid can escape, and it can then no longer be guaranteed that the unit can be sufficiently filled and bled.When installing the hydraulic unit, ensure that rubber dampers are not pressed out of bracket.]
- Before installing holder of ABS hydraulic unit N55 on bracket, spray rubber dampers with silicone lubricantD 007 000 A2.
- Using assembly toolV.A.G 1410/8, carefully fit brake lines.
- Connect battery Electrical system27Battery; Disconnecting and connecting battery.
- Remove brake pedal depressorV.A.G 1869/2.
- Bleed brake system .
Other VW procedures
- Removing engine · 41 torque figures
- Removing and installing camshaft · 47 torque figures
- Adjusting valve timing · 83 torque figures
- Removing and installing camshafts · 39 torque figures
- Removing and installing coolant pump · 53 torque figures
- Adjusting headlight installation position, as of model year 2010
- Removing and installing brake disc, brake caliper FS III
- Removing and installing brake carrier for disc brakes
- Removing and installing splash plate for brakes, twist-beam rear axle
- Removing and installing brake caliper piston; Rear brakes, Bosch ZOH BIR 38
Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.