I replaced the mst cyl. how do I bleed the ABS sys to get the air out? 97 ford F-150

You bleed it like you would a normal system but you must use the boost assist to do it, in order to do this start the truck pump the brakes three times and bleed that cylinder farthest away from the master cylinder do this twice or until you get clear fluid to run out. add fluid for every cylinder before moving on. Do this for each wheel and after doing all four wheels you should be ready to go. If it feels mushy you will have to bleed it a second time. But you must have the engine running to bleed the brakes unless you have a power bleeder. You may want to bleed the master cylinder first to do this add fluid to the cylinder then pump brakes three times crack the front line open and allow it to bleed air rout of the line do the same for the rear master cylinder once yo get solid fluid from the master cylinder you can dot the same for the ABS then do the wheel cylinders and wheel calipers. This needs to be done sometimes, be sure to never let the master cylinder run out of fluid and check it each time you bleed the wheel cylinders.

This requires an electronic special tool to open the ABS pop valves, there is no other way to bleed the module, u will need to have the dealer finish the bleeding or a brake shop with the tool.

If all you changed is the master and then benchbled it properly you should not have to bleed the abs, bleed the master st the lines and all should be well