ABS Power Unit.

johnmowcop said:

Some advice please.

I just bought a 2.5 DSE. Really pleased with it, but:

The abs power unit does not always kick in and then the brakes vanish. ABS and red stop light come on on the dash.

I have fiddled around the power unit looking at connections etc and found that the end of the motor, the end away from the pump where the wires enter, is fairly free to partially turn. As soon as it is touched the motor kicks into life and the system is pressurised and the motor then cuts out. I press the brake and it kicks in again for a few seconds then cuts out. I keep doing this for half a dozen times or so and then the motor does not kick in. If I again touch the end of the motor it operates again.

For now I have put a cable tie around the 'end plate' of the motor and all seems well. This is obviously not a safe way to leave it, I have not really solved the problem.

I assume there are brushes behind the end plate and guess it must be worn brushes or a bad connection. I need to get at these, the manual says the abs power unit is a sealed item.

My question is: Has anyone taken the motor off the power unit. It looks to me that if the cap screws are removed at the pump end of the motor the motor should withdraw from the pump. Is this so? Can the motor be removed without disturbing the hydraulics of the brake system.

Your comments would be appreciated.

Click to expand...

johnmowcop said:

Some advice please.

I just bought a 2.5 DSE. Really pleased with it, but:

The abs power unit does not always kick in and then the brakes vanish. ABS and red stop light come on on the dash.

I have fiddled around the power unit looking at connections etc and found that the end of the motor, the end away from the pump where the wires enter, is fairly free to partially turn. As soon as it is touched the motor kicks into life and the system is pressurised and the motor then cuts out. I press the brake and it kicks in again for a few seconds then cuts out. I keep doing this for half a dozen times or so and then the motor does not kick in. If I again touch the end of the motor it operates again.

For now I have put a cable tie around the 'end plate' of the motor and all seems well. This is obviously not a safe way to leave it, I have not really solved the problem.

I assume there are brushes behind the end plate and guess it must be worn brushes or a bad connection. I need to get at these, the manual says the abs power unit is a sealed item.

My question is: Has anyone taken the motor off the power unit. It looks to me that if the cap screws are removed at the pump end of the motor the motor should withdraw from the pump. Is this so? Can the motor be removed without disturbing the hydraulics of the brake system.

Your comments would be appreciated.

Click to expand...

johnmowcop said:

Some advice please.

I just bought a 2.5 DSE. Really pleased with it, but:

The abs power unit does not always kick in and then the brakes vanish. ABS and red stop light come on on the dash.

I have fiddled around the power unit looking at connections etc and found that the end of the motor, the end away from the pump where the wires enter, is fairly free to partially turn. As soon as it is touched the motor kicks into life and the system is pressurised and the motor then cuts out. I press the brake and it kicks in again for a few seconds then cuts out. I keep doing this for half a dozen times or so and then the motor does not kick in. If I again touch the end of the motor it operates again.


For now I have put a cable tie around the 'end plate' of the motor and all seems well. This is obviously not a safe way to leave it, I have not really solved the problem.

I assume there are brushes behind the end plate and guess it must be worn brushes or a bad connection. I need to get at these, the manual says the abs power unit is a sealed item.

My question is: Has anyone taken the motor off the power unit. It looks to me that if the cap screws are removed at the pump end of the motor the motor should withdraw from the pump. Is this so? Can the motor be removed without disturbing the hydraulics of the brake system.

Your comments would be appreciated.

Click to expand...

johnmowcop said:

Hello TakDriver.

Thank's for your comments and help.

This morning I removed the pump from the brackets (I did not disconnect the hoses, just raised it up to look at the end of the motor) and removed the plastic end cover (yesterday I thought I was moving the end of the motor, but it was just the plastic end cover). It seems that the two wires that are attached to the motor are pulling down on their connections, the wires are routed and bent fairly tightly around the body of the motor. I cut back the plastic sleeve on the wires, not the insulation, which allowed a bit of slack to be given to the connections, this seems to have sorted the problem for now. But I will be aware of the potential for loosing brake assistance if the problem returns.

John

Click to expand...