I havent been too active one here but I'm always reading. I did make a few posts and get some help with the direction we were taking and hopefully now someone can help get us the rest ofthe way there. So we got the brakes all run, Boling bros brakes all the way around, 3/16 brake lines run and the boling bros battery box / master cylinder. 10lb residual valves front and rear pretty close to the master cylinder and a proportioning valve. We flipped the rear brakes upside down to clear the spring perch. Bled everything out , im not getting any more air when i bleed. I saw a thread somewhere on here about pushing fluid into the bleeder valve and cracking the brake line to let the air out when the wheel cylinder is mounted upside down. That appeared to be successful as well. Brakes are all adjusted out ( probably a couple clicks too far) the pedal feel is not totally consistent and the stopping is not exacly consistent. I have had them lock up and skid to a stop but its not every time. Also, the pedal isnt returning as high as I would think it should, I'm sure the bushings are worn in the pedal but i dont think that would be reason enough. I feel like it has to be air in the system still but im not sure how to proceed other than just keep bleeding. Heres a updated pic of how its come along.
When you say wheel cylinder is upside down, does that put the bleeder below the center of the cylinder? If so, why can't the cylinders be swapped side to side, so the bleeder valve is above the cylinder center? Just a thought.
I tried that early on and drilled out the baking plate not realizing i couldnt get it to the right spot on the backing plate and the pistons were at an angle. If that makes any sense.
One way to check for air is to pump the master cylinder up, push hard and watch the reservoir when you quickly release the pedal. With no air you should see the fluid returning via the compensating port/ports in the master. It will be a "swell" in the fluid that may rise slightly over the fluid level. If you have air in the system, the fluid will or almost will jump out of the master cylinder when you release the pedal. When you pump it up with a lot of foot pressure and quickly release the pedal, the compressed air bubble shoots the fluid back to the master cylinder with a lot of force.
Reread your post. If I was to crack a brake line fitting, to bleed, I'd crack the one at the upside down wheel cylinder. Again, just a thought.
Thats the line i was cracking open. I appreciate everyone's thoughts. Mine aren't getting the job done.
i just stepped in the garage to check this and when i step on the pedal its just shooting fluid out of the top of the mc with the lid off. Ill have to lower the level tomorrow to test it this way.
Take the backing plate/shoe assy off and bleed both rear brakes with the bleeder at the highest point..
Take a brake drum off and post a picture of one front and one back brake so we can see what you are working with. Also are you sure you don't have a master cylinder with residual valves in it already? Is it a single or dual master cylinder? A picture of that may also help.
Its a single mc. Its the boling bros mc / battery box . Not the best picture , i can upload a better whe i get home if its helpful. I dont have a pic with the front installed but here it is on the bench.
With the backing plates upside down, does that effect the way the shoes grab the drum when rotating? I just remember getting the primary and secondary shoes backwards once and have the brakes grab pretty bad.
I think you have the short shoe in the wrong place. Picture the backing plate with the wheel cylinder at the top. The front shoe should be the short shoe. Now turn the assembly upside down, the short shoe should be at the back to work correctly. Have you checked to see if that master cylinder already has a residual pressure valve built in. Most single bowl drum brake masters do from the factory.
You might have to remove the rear backing plates with all lines connected and and position the wheel cylinder so the bleeder is at the top. However, I don't know if that's possible. Maybe you could remove the wheel cylinder and set up something to bleed the air out, then cap it and reinstall. When I first put the car together in my avatar, I couldn't get a brake pedal. This was with a single circuit master cylinder mounted higher than the calipers. I finally made up a plug to fit in a brake line at the fitting. I started with the plug in the line coming from the master cylinder and got a firm pedal. I moved the plug to the next connection and bled to get a firm pedal. I kept moving my plug until I got firm pedal at each connection in the system. The bubble was somewhere in the the rear lines. I did notice a later picture which shows you have the primary and secondary shoes reversed.
Total guess, but can't the wheel cylinders be flipped over (turn 180 in the current position)? If so, the orientation of the cylinder will be the same as stock, bleeders uppermost etc. Chris
On the rear brakes, I just cut the shock mount off of the perch and the backing plate fits perfectly, right side up. I was putting tube shocks on and had no use for the original ball mount, anyway. Looking at your nice, clean installation I see a lot of stuff you neither need in the system you have, nor should have in the line. That type of setup never used such things and they shouldn't with a single bore master cylinder. They work very well without all that stuff and always did. You're causing yourself a problem. Lines straight from the MC to the wheel cylinders. Do yourself a favor and get rid of it. These brakes can often be a real pain in the ass to get all the air out without all that stuff. I don't know why people have to make it more complicated than it needs to be. Be sure the shoes are installed in the proper location. Primary shoe to the front. Secondary to the rear. Done right, you will be very happy.
We are good to go. We ordered this little oil transfer pump from amazon, cracked the brake line on the upside-down wheel cylinders and forced it through the bleeder. We did this before but without the pump and after thinking about it realized our first attempt was too little fluid for too short a time. I just wanted to post a follow up in case someone in the future runs into this issue and comes across this thread.
Not sure what the oil transfer pump cost, but when I was wrenching, we had a hand operated unit called a ''mytvac brake bleeder''. It was capable of vacuum, or pressure bleeding, depending where the supply hose was connected to the reservoir.
This thread is perfectly timed for me as my 'new' model A has had juice brakes fitted, but they're very poor and hard to bleed. I had a look yesterday and just like yours my back plates are also upside down/wrong sided, I'll be deleting the ball mount, fitting tube shocks, and flipping and swapping the back plates.
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