Hard Line from ABS to HCU replacement?

[TitaniumSHO]

1990 MTX

One of the lines that runs from the top of the HCU(Hydraulic control unit, little black box on the inside of the fender) along the inside of the fender to the ABS has ruptured. I have searched extensively but I have been unable to find anything regarding my problem. I need to replace that line(or all of them, as preventative maintenance) and I am unsure how to go about doing this. The end of the line going into the ABS just screws in, but the end of the line going into the HCU doesn't appear to screw in. So I guess my question is: How do I disconnect the line from the HCU? Do I need to unbolt the HCU from the fender wall to do so? If anyone could give me semi detailed instructions on what I need to do I would REALLY appreciate it, thanks.

 

[rangerj]

The 4 tubes to the outlet ports and the 2 tubes to the inlet ports of the HCU are held in with typical tube nuts. The nuts are installed at 10 to 18 foot lbs. torque.

I think the tubing size will be 3/16 steel tubing (double wall steel brake tubing). You can get this in bulk by the foot at auto parts stores. The nuts are 3/8 by 24(thread pitch) tube nuts, but check the ABS nuts because they may be metric. I know some metric nuts are used but I cannot recall where.

You will need a tubing cutter available at any hardware store (Home Depot for example). You will also need a tubing bender to match the bends of the old lines. These are relatively cheap at places like Northern Hydrolics or other cheap tool places. You can also get one at Auto Zone or Sears. Given the age of the car I doubt you will find OEM pre-bent lines.

Lastly, be sure to check the end of the lines for the type of flare used. Both ends may be ISO type flares, or they could be "double flares", or one end may be ISO and the other end double flare. A brake line flaring kit is available at Auto Zone. You can "rent" it by paying for it and returning it when you are done. This may be true of the tubing bender also.

One more thing. You will have to bleed the ABS when you are done. Research the prior threads on how this is done. It is not the same as bleeding the rest of the system.
rangerj