Hello,
I have a question for everyone here. I recently bought the scarebird brakes disc brake conversion kit for my 70 f100, but after changing all the parts out I am having a problem with my brakes dragging. Any advice on how to correct this problem would be appreciated.

Thanks

 

The fronts & the rears also. Open the bleeder real fast and close it see if any air in your system.
orich

 

Dragging brakes is typically residual pressure.

Give is more info... what exactly does the Scarebird consist of and describe how it is set up/installed. What disc/drum prop valve did you use?

Thanks.

 

Mine dragged when they got warm it was the rod behind the master cylinder was to far out and caused them to drag. I have power brakes. I adjusted the rod so master cylinder would slide on with no pressure from the rod on the master cylinder took a few times to adjust the length.

 

Well that figures, that's like driving with your foot pushing on the pedal while driving.

What would make you think that you needed to compress the m/c piston some ?

Orich

 

Did you change the master cylinder? If you did, check the length of the new rod. I had the same problem and the cause was a rod too long. Forced partial pressure on the master cylinder.

 

On mine it was a new set up from a 1977 I put on with new m/c and booster. My rod was adjustable.

 

This is the time you guys should have listen to that little inner voice you hear saying oh am, I doing right.? Oh how hard can this be. But then don't listen and over torque things or assemble something wrong.

I know it's just easier to do things your way and think aw heck, I don't need a manual to do this is easy. But later you find out the hard way and have to redo the whole thing over..

Many guy don't think they need a torque wrench until they break a bolt or two..

This is the reason, I'm always posting it time to get a manual, only to save you time & money in the long run..
Plus you learn how it's done correctly and can tell the next guy how to do it right..

Ok So now, I'll go take my meds and a little nap!

Orich

Orich

 

If the disc brakes are added to the front and the same or incorrect master cylinder is used, you will have too much residual pressure. Drums brakes need 10lbs, whereas discs use only 2 lbs. You need the correct disc brake master cylinder.

 

Original, factory-installed, MCs would have had an RPV in the port that supplied pressure/fluid to a drum brake circuit(s).

Most parts store replacement MCs don't come with an RPV installed in the ports any more, even if the OEM application did have them.

Cup expanders in the wheel cylinders have pretty much made residual pressure valves, inside the MC, obsolete. Cup expanders keeps the lip of the cup seals tight against the bore of the wheel cylinder. This keeps air from being drawn in around the seals and into the wheel cylinder bore.

IF you have an old street rod with a MC mounted below the floor board, then you may need the inline RPVs to control fluid drain back to the MC. If your MC is mounted high on the firewall, gravity isn't going to make the fluid drain uphill.