Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Control Module, Installing On Hydraulic Unit: Notes
Assembly is performed in reverse order. Note the following:
A new ABS Control Module -J104- can be installed on an old ABS Hydraulic Unit -N55- a maximum of two times. This assures the elastic seal will not leak.
A used ABS Control Module -J104- may not be installed a second time.
Excessive shaking (for example, dropping, impact) may destroy the control module. The control module must then no longer be used.
Special Tools And Workshop Equipment Required
- Surfaces must be cleaned before assembling.
-- Slide all seals -A- slightly over the valve body.
-- Place the ABS Control Module -J104- on the ABS Hydraulic Unit -N55- without tilting it.
Seals are then brought into their end position.
-- Install the ABS Hydraulic Unit -N55- and the ABS Control Module -J104- with the new screws provided, diagonally and in stages, to the tightening specification.
The hydraulic unit threads cannot be re-cut to secure the control module. In the threads are damaged (bolts are difficult to install by hand or the bolts cannot be tightened to the tightening specification). The hydraulic unit must be replaced.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.