Lincoln rear brakes arent stopping the wheels!!

[SmockDoiley]

So a few weeks ago, I did the swap to Lincoln front brakes on my 85 GT and everything worked fine. Well I just got done installing the rear Lincoln brakes along with my new rearend, and when I press on the brakes, I have to press as hard as I can to get the tires to stop and they dont stop all the way. I dont remember this being the case with any other car. To date, I have installed the SVO M/C, APV, front and back lincoln disc brakes, and everything is brand new. I bled everything and there doesnt seem to be any air or leaks anywhere, and the pedal feels pretty good. Also, I used the flipped brackets trick in case that helps with diagnosing. Anybody have a similar problem or some guesses before I head back to the hobby shop tomorrow to hopefully sort everything out. Thanks in advance, Scot Rod

 

[BlackFox5.0]

Are you sure you adjusted the prop valve correctly?

Turn it out all the way, and 4 turns in as you inital adjustment, and go from there.

How does your pedal feel? What front brakes are you using? It's possible that your MC could be too big if you have small front brakes.

 

[SmockDoiley]

I just posted all that stuff that you asked. Besides, like I said the fronts work fine, and it didnt seem to matter whether I adjusted it all the way out or all the way in. Could it have to do with the rod adjustment going into the MC? I adjusted it out a few turns like suggested to accomodate for the new beefier MC.

 

[Michael Yount]

If the fronts work fine, but the rears don't I'd suspect something to do with the proportioning valve.

 

[91BlckGT]

So a few weeks ago, I did the swap to Lincoln front brakes on my 85 GT and everything worked fine. Well I just got done installing the rear Lincoln brakes along with my new rearend, and when I press on the brakes, I have to press as hard as I can to get the tires to stop and they dont stop all the way. I dont remember this being the case with any other car. To date, I have installed the SVO M/C, APV, front and back lincoln disc brakes, and everything is brand new. I bled everything and there doesnt seem to be any air or leaks anywhere, and the pedal feels pretty good. Also, I used the flipped brackets trick in case that helps with diagnosing. Anybody have a similar problem or some guesses before I head back to the hobby shop tomorrow to hopefully sort everything out. Thanks in advance, Scot Rod

When you put the new APV valve in, did you remember to gut the stock P.V.? As in removing the spring, the little piston valve, and putting the M-2450A plug in it's place?

 

[Mustang5L5]

When you beld the rear brakes, did you remove the rear calipers and wedge a block of wood in them and bleed them with the screw up? The rears like to trap a little air inside them when you bleed them on the car.

Also, are these new or used calipers? Used Mark 7 calipers have a habit of freezing up when they sit. I went through 2 frozen boneyard calipers.

Final suggestion...you did gut the stock Prop valve right? I assume you did but just trying to cover every angle

 

[BlackFox5.0]

If he had air in the calipers he would have almost no pedal at al, it would go straight to to floor...

 

[SmockDoiley]

Like I said, everything is brand new, and I did gut the stock PV. I forgot about that, could there be something I left in there. I swapped the front nut, and pulled out the spring and that rod or plunger thing(whatever it is)