SSBC disc brakes won't stop

71Demon said
Tried this but no change in the fronts. There was some pressure in the rear lines when I opened it up. Still just slowly stops. Thinking not enough pressure to the calipers. IDK for sure though.

Well then we better check that the compensating port is open.
Let me start by saying, if you were able to bleed the front brakes, and you have not changed anything to do with the M/C, or it's pushrod or the brake pedal, since then; then I think your C-port is just fine.You can skip over everything, and go down straight to HERE
But if you have messed with any of those, then here we go.
Have a helper in the car. You pop the cap off the M/C.Make sure the P-valve is open,and the clamp is loose on the back flexhose, and at least one bleeder loose, if the rear has not yet been bled.If you don't have Dot5silicon fluid, and you DO have paint you wanna keep, then you need to drape everything within about a two foot radius, with something that will prevent direct contact of the brake fluid to th paint, cuz the next step is unpredictable.With drum brakes, I also protect the underside of the hood.
While you eyeball the fluid in the reservoir, and shine a little Maglite down into the fluid, have your helper very gently press down on the pedal and stroke it about 1/4 of the way to the floor or about 1 to 1.5 inches;and hold it there. You should have observed a slight roiling of the fluid.This is a good thing.
-Now the tricky part. Have your helper very slowly let the pedal up. You should see a little fountain above the liquid line.If the helper lets up too fast, the fountain can become a gusher, so SLOW is the operative.Repeat several times as may be necessary, increasing the stroke a little bit each time, until you are sure you have seen it.Then end the test by securing the cap.
---Now the interpretation:
NO roiling at all, and NO fountain; the C-port is not working.
Roiling but NO fountain at all.Your flexlines ain't flexing and your pistons ain't moving.
Roiling and a TINY fountain; probably the pistons ain't moving and the flexhoses are flexing normally;but could be the reverse if you have teflon-lined hoses.
Roiling and SMALL fountain; this is normal.
Roiling and a gusher; there is compressed air forcing the fluid back.
-If the pedal cannot be depressed with the rear bleeder open, and with fluid or air dripping there, then the front is either mechanically or hydraulically locked.
-To find out which, you will have to crack a front bleeder. If fluid spurts out, you probably have a hydraulic problem, but not for sure. If no fluid spurts out, you will have to check the other side. If no fluid spurts out this side either, then you will have to crack the fitting at the M/C. A spurt here means at least one of the flex hoses is plugged, or the distribution block is, if you still have one.After the spurts, you should again have pedal travel, until it all locks up again.
But if there are no spurts anywhere,then the piston inside the M/C is locked up. If it is stuck at the end of it's travel,and not returning to it's parked position,the pedal will be very low. But if it is stuck at the top of it's stroke, the pedal will be normal.If it is stuck partway, the pedal will be a little low, and If you have a booster,you will be able to lift it back up with a toe, and then it will fall down again.Try not to lift it more than a few millimeters.With no booster, the pushrod is mechanically anchored at both ends,so you won't be able to lift the pedal very far.
Ok so now we have to figure out why it's locked. To do that, you will have to install the bench bleeder hoses in both outlets, looping the hoses back into the reservoirs, and into the fluid. Then get your helper to again slowly push the pedal to the floor, while you observe the fluid action.Then very slowly return the pedal to the top.If the pedal now moves back and forth, then the pistons were not mechanically stuck.Stroke it several times until no more air comes out of the hoses.While doing that, shine your Maglite down directly into the compensating port. If the port is large enough you may see the piston moving back and forth in the hole. Well what you might see the edge of it. It is aluminum and will flash at you as it goes by.It may also still roil the fluid, but you will have no fountain.No matter cuz if the fluid goes round and round,and round, then the port is working. But if the fluid just goes back and forth in the hoses, then the port is not working.The way to see that is to pinch the little hoses when the pedal hits the floor. Then when the pedal returns the pistons will collapse the hoses trying to draw the fluid back.
HEREAssuming by now you are confident that the M/C is working properly, leave the bench bleeder on for the rear system(which is the port nearest the rad), and re-connect the front system(which is the port nearest the firewall).You can bleed the fitting right at the port, and get most or even all of the air out. But the the next step will send any air back into the reservoir. Or if you jumped to HERE, just leave the rear system open, with fluid able to be collected in a little jar. Follow that firewall-side line to make sure it goes to BOTH of the front brakes.
So now give the pedal a few stabs.The pedal should get hard,about half way down.The open rear system should not affect anything except the pedal will travel a little further and will not return to the top.That is normal.
Now, the big question is does the outgoing fluid get to the calipers, and do the calipers respond by putting a bite on the rotors.And when you release the pedal, does the caliper release.So check it.