This is driving me crazy and I need some help. I have drum brakes converted to power drum brakes. Replaced 2 wheel cylinders, I am on the 3rd PB MC and have bled the system at least 6 times with good results. The booster worked off the power disc brake car it came from. The rod is the correct lenght and angle from the pedal to the booster. Of the 2 rods lenghts used from the booster to the MC, I have the longer one. It touches the indentation on the MC. The pedal goes to the floor and will stop the car on a roll and it shutters when rolling down the driveway. Now what guys???? I followed all the suggests from you guys awhile back.

I wonder if the shutter is from some oil on the shoes? The low pedal could be air ( its ver hard to get air to move down hill in fluid), bad adjustment of the star wheel, emergency cable holding up the shoes, Master,, Try to see if any ft or back gets any drag with just a touch of preasure on the pedal.

Make sure your shoes are adjusted all the way out against the drums. if you turn a wheel by hand when it's in the air, you should feel a slight drag. If you give the wheel a spin and it just keeps on spinnin'... the shoes aren't adjust out far enough.

Hard to say what the shudder is caused by... could be contaminated brake shoes, but first thing I would do is make sure the shoes are out against the drums.

Make sure your shoes are adjusted all the way out against the drums. if you turn a wheel by hand when it's in the air, you should feel a slight drag. If you give the wheel a spin and it just keeps on spinnin'... the shoes aren't adjust out far enough.

Hard to say what the shudder is caused by... could be contaminated brake shoes, but first thing I would do is make sure the shoes are out against the drums.

Yes, drum adjustment is critical to having a good pedal. You should tighten the adjuster until the wheel can't be turned to center the shoes, then loosen it enough to turn freely. Tightening the adjuster to lock the drum will seat and center the shoes, without doing this, the shoes may be off-center and drag a bit giving you the impression you need to back off the adjuster more than is proper.
Last resort, you can clamp off a brake hose to isolate the problem area, I use needle nose vise grip pliers, with aluminum padding on the jaws. I don't clamp too tight or hose damage will result, just enough to stop fluid flow. If you clamp off a hose and the pedal is greatly improved, then you have found what area needs work.
David

More of the story. I removed the complete drive train from one car to another. The brakes worked fine in the doner car. I have not touched the adjustment of the shoes because they worked fine in the car before I trasfered the sub frame and rear end to the doner car. The car has no E brake cable. The only thing I did different is transfer the working brake booster and proportioning valve to convert the brakes to power drum brakes. I have rechecked the adjustment on the almost new shoes and have cleaned them and the drums with laquer thinner. Now what???

Do you have the brake pedal pushrod hooked up to the lower hole on the brake pedal arm?.....Also, be advised, there is no proportioning valve for drum brake cars, just a distribution block.

Would the distribution block or proportioning valve be one in the same? I took it from the Disc brake car. The original distribution block when it was a non power brake car looked the same as the one off the disc brake car. I tried them both and no difference. This cannot be rocket science. I and the local mechanics are stumped as well. Everyones suggestion I have tried ann there is no difference. Well now the car is all restored and I am ready to sell but there is no brakes. The car looks great and is ready for a new home so I can get after my BB RS/SS car that has the drive train from the for sale car!!!!!!!!!!!

Yes it is in the right hole!

Have you tried a mini vac or preasure bleeder? It is very hard to get air to move down hill in fluid. The prop valve for disc is different than the style for drum.

Perhaps you have the wrong rod in the M/C? Maybe it's too long and it's depressing the M/C bore. Try the shorter rod.

If the brake pedal feels spongy and drops down then there still has to be air in the system!

Thanks guys. I will have the system bled again with a vac. I will try the shorter rod and look at the splitter, even though I have tried both and no difference. The story will continue and my son "RamAir Dave" doesn't know the answer. I could just go back to no power brakes!!!
Bruce

Would the distribution block or proportioning valve be one in the same? I took it from the Disc brake car. The original distribution block when it was a non power brake car looked the same as the one off the disc brake car. I tried them both and no difference.

I don't know for sure, but there could be a possibility that the disc brake valve isn't compatible on a drum system. Do you have the brass valve on the subframe from the disc system?

Dave,
That brass valve is on the disc brake car. My guess is it is the prop valve is not doing the job. I cannot find that there is any difference except for the "round" valve that is not not on this system, per the Camaro assembly manuel. Does anyone have a prop valve from a power drum brake car? Talk to you later, Dad

A friend of mine had the same problem with his 69 camaro.he eliminated the distribution block and only used the proportioning valve. Did you bench bleed the master cylider well enough?

I bench bleed both MC that I have used. The "round" prop valve is used on disc brakes according to the assembly manuel. The distribution splitter block directs the fluid to the front and rear brakes. All 4 of my 69's have that splitter as well as my Chevelle. Thanks for the info.

If your master cyl has deep hole, then use the long pushrod, if the hole is very shallow, use the short rod. Read this: http://www.pozziracing.com/brakes.htm#Booster
The master cyl piston MUST return fully or it won't be replenished, or vent properly.

Check out how your distribution block is plumbed into the system. The MC front goes to the front, rear to rear.
David

Thanks for all the help in trying to get my power drum brakes to work. I finally solved it by looking under the dash of 2 of my other 69's and found the pedal to be 5" from the floor. Well that was only 2" on the "no Brake" car. It had been converted at one time from a 4 spd to a automatic. The pedal used was incorrect! I installed the correct pedal and the brakes work perfect. Now I can sell the car and work on the next one. . . a BB RS/SS optioned out and nothing original!!!

Thanks for the update!
I'll attach this post to your old thread so it all is in one place.
David