Just curious if anyone has had this problem before. I'm finishing my up '58 Chrysler's new brake system and can't get any pedal. All new calipers, wheel cylinders, hard lines and hoses, no leaks. New Strange master cylinder and SSBC distribution block. Before you state the obvious - air in the lines - I can assure you the lines are free of air. I've bled them to death and any of the 4 corners will flow clean, bubble free fluid for as long as you keep replenishing it. Even with air in the lines, the average car will have some pedal - this car has no pedal. I can look up at the cylinder from inside the car and see the piston going in over an inch when I push the brake pedal - there's just no pressure being built.
How did you bleed the brakes? Old fashion way - pedal push, or some other way? Did you bench bleed the MC? If you bled the brakes without using the MC, then I would look over the MC for any problems. Perhaps the push rod is too short.
First, can you fully bottom out the master before the pedal runs out of travel? Check with both systems open. If full stroke is not available, successful bleeding of that design master may not be possible. Second, If you are capable of a full stroke, and there are no external leaks, then you possibly have a displacement problem, caused by an internal bypass leak in the master, insufficient fluid volume for the calipers and wheel cylinders (doubtful), or....a bad bleed. Low drag GM calipers and rear drums brakes out of adjustment could also be part of the problem.
I've bled brakes for 30+ years and these brakes are bled....I first gravity bled them, then vacuum bled them, then pressure bled them. There's no air in there. The MC is getting a full stroke...but in normal operation it only strokes a tiny bit anyway. I should mention this system is identical to my other car which bled normally and works fine just 6 months ago. My theory is the MC has a problem and is not pushing any fluid...like maybe a seal is missing or ???? The PITA of brakes systems is the fluid is not like water - you have to be super fussy about where you let it go or you'll be repainting something.
Is the m/cyl piston retracting fully ? A "too-long" pushrod from the pedal may not let fluid return....... 4TTRUK
If your getting a full stroke. (no brake light switch restricting ect) and your bleeders are all facing up ( if the calipers are on the wrong side they will face down, bleeding achieved but not all the air removed) There is a possibility of a stuck proportioning valve. ( a couple of hard slams on the peddle normaly free a stuck valve) Then its gotta be the M/C.....
The bleeders are all up and there is no prop valve...it's just a distribution block. Anyway, I ordered a new MC that will be here tomorrow so I plan to change it out to see what happens. I don't like the 'change it out to see what happens' approach but that's the point I am at with this one.
before you change it, Pull the lines off at the master. Put a plug in each port (or if you can't find one take two small lengths of line with the fitting on them and either crimp them over, or solder/weld the end of the line). Then pump the pedal - it should be rock hard, or close to it. If it depresses to the floor,even slowly, then the internal seals are no good or there is a defect in the casting. If you can pump it up and it holds pressure, there is air in the master.
It's a good idea to plug the master but in practice I want to minimize the amount of time and playing around I do with the master cylinder while it is in the car. I have fresh white paint all around and I don't want to tempt fate. The last time I had a defective MC (and it was a manufacturing error), it sprinkled the brand new paint of my other car with fluid and before I could clean it up....I have a bunch of speck of paint missing on my inner fenderwell that is a major PITA to remove and respray.
It's a good idea to disassemble master and wheel cylinders before use, both new and (especially) rebuilt, to check for obvious defects, damage and foreign matter. Keep a spray bottle of isopropyl/denatured alcohol handy to clean brake hydraulic parts and fittings (to better check for leaks), and fluid spills, which will help minimize any paint damage.
A thought (though you probably already did this) is if the brakes are adjusted correctly. If the brakes are not adjusted correctly, then the brake pedal will sink to floor. Sure you can get all the air out of the system, but your pedal will go to floor as if you had no drums on the brakes. Again, just a thought.
I thought the exact same thing. Easy to check out, and eliminate from the list of potential issues ...
sounds like the first master cylinder i on my 62 ford.. the o rings on the piston actually rolled and caused a huge amount of fluid blow by... so they would blead because it wasnt under too much pressure when you cracked the bleeder.. but when you tightened it back up and wanted to test the pedal.. it went to the foor... when i tore it apart, now mind you this is a "new" mastercylinder.... i found it was bored .025 over and has terrible score marks down it.. i was lucky to have a stainless sleeve kit and pitson to match so i had my friend bore it out and put a liner in it. i jsut dont trust "new" or "reman" id rather fix old junk with a few more hours and machine work fixing and old master cylinder. just my opinion though.
Some calipers need to be mounted so that the bleed nipple is at the highest point. In many retrofit jobs, the caliper mount differs from OEM, leaving the bleed nipple at a low point, causing a trapped air bubble in the caliper.
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