240 Brake caliper with no punch marks

1988 245. I'm having trouble getting a good high pedal after a full break overhaul (rebuilt calipers, all new rubber hoses, 91 style brake distribution block and reservoir, master cylinder)... Unique, I know. my drivers side rebuilt caliper has no punch marks at all. Passenger side does. Anybody ever run into a caliper with no punch marks? I should have checked that the bottom line has continuity with the bottom bleeder, huh? I suppose I should check it for my peace of mind. I'm almost positive that's got to be the issue. Engine off the pedal feels really hard and high. Once the Engine is running and I have that brake booster assistance it sinks down about halfway, enough to deplete the booster and drop the idle.

You could check that the lower bleeders are connected by blowing air or pushing/sucking brake fluid from one to the other.



If the caliper was assembled wrong they won't be connected.

I took off the outboard pad, and pushed the bottom cylinder in while opening the bleeder. Fluid squirted out, so I can cross mismatched caliper halves off the list. I'm now suspecting the rear proportioning valves. I get fluid through them, but maybe they are crudded up enough to trap air, I don't know. I have the car jacked up all the way in the back on jack stands, and the front is all the way down on jack stands. I figure I'll go through the bleeding another time with the engine running and an assistant instead of the power bleeder while smacking those proportioning valves just to be sure it isn't just a stubborn bubble.

Would it be industrious of me to pull the rear proportioning valves and clean them out with brake cleaner and compressed air?

This was my bleeding procedure after everything was apart.

-bench bled master.
-installed brake junction tightening down all lines except the top two that run to the back.
-installed master.
-once fluid was pouring from those top two connections on the junction, I tightened them down. I did this to hopefully bleed the junction and not send a bunch of unnecessary air back to the proportioning valves.
-Installed motive power bleeder, pumped up to 20 lbs.
-bled the front two calipers top and bottom, bucking the prescribed brake bleeding order, just to make sure I got as much air out of that junction as I could before bleeding the rears.
-Then I went through the normal brake bleeding sequence twice, using a quart of fluid. DR, DF top, PF top, PR, PF bottom (inside and out), DF bottom (inside and out). Many bubbles were bled out, and when I stopped only clear fluid flowed from the bleeders.

91 non ABS style brake junction. Pull-a-part score!


91 non ABS master resevour with switch. Pull-a-part score! (will hook up switch soon.)


Bonus pretty B230FT that I'm getting ready to put into this wagon.
Before

After

intothelabyrinth said:

I took off the outboard pad, and pushed the bottom cylinder in while opening the bleeder. Fluid squirted out, so I can cross mismatched caliper halves off the list. I'm now suspecting the rear proportioning valves. I get fluid through them, but maybe they are crudded up enough to trap air, I don't know. I have the car jacked up all the way in the back on jack stands, and the front is all the way down on jack stands. I figure I'll go through the bleeding another time with the engine running

Click to expand...

Engine doesn't need to be running.

intothelabyrinth said:

and an assistant instead of the power bleeder while smacking those proportioning valves just to be sure it isn't just a stubborn bubble.

Click to expand...

Tapping with the handle of a screwdriver is sufficient.

intothelabyrinth said:

Would it be industrious of me to pull the rear proportioning valves and clean them out with brake cleaner and compressed air?

Click to expand...

No.