Steve340
Well-Known Member
The pictures were not great but the drums seemed scored and have some weird marks.
73 Soft Pedal Learning Process
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Challenger RTA
Well-Known Member
The proportion valve does go bad
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Ricks72Chlgr440
Well-Known Member
I had an A body car with power brakes that I replaced the MC in. The pedal went almost to the floor before the brakes engaged. I pulled the master away from the booster and lengthened the pushrod. Worked great for a couple of days. As I was driving once after that and applied the brakes the brakes locked up tight. I shortened the rod a little and all was good. Think the master still had some air and the rod was just a bit too short. My experience anyway!
Challenger RTA
Well-Known Member
Post a picture of the brake parts that are installed.
If you go to post #4 in this thread, on page 1, I have provided photos already that may be helpful. Please let me know if you need additional photos. There are a couple of the metering valve and the Wilwood adjustable proportioning valve I had installed.
Right now the fluid level in the MC is good - I thought it might be leaking into the booster. But it has held steady for a few days since I topped it off. I have a booster pushrod gauge coming and once it gets here I will separate the MC and booster and make any needed adjustment with the guage, and check for leaks.
I remembered recently that I bought this MC a long time ago and provided it to the resto shop that did the brakes.
I last fired up the car and moved it a week and a half ago. At that time, I verified that I do have brakes - it is just that they do not grab until my foot is very close to the floor. For that reason I suspect the booster pushrod. But I won't know until I take a look at it.
Thanks on this! I ordered a booster pushrod gauge because I want to try and get it right the first time and not have to take it apart again. What I am seeing online is necessity to make sure there is a .010 gap, and I have feeler guages for that. Hopefully I can just move the MC forward without screwing up the lines. If the MC is leaking, well that is another story. And of course the fluid could damage the rubber parts in the booster.
Challenger RTA
Well-Known Member
A picture tells the story. This is more then likely your problem. Been there done that. If I had a dollar for every time that I bleed brakes. I wouldn't be here! Only had this problem one time.
Get the clip. Don't need it. Make sure it moves freely. Pull it up clip vice grip or other or just have someone hold it up when you bleed the brakes.
Get the clip. Don't need it. Make sure it moves freely. Pull it up clip vice grip or other or just have someone hold it up when you bleed the brakes.
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Challenger RTA, I see the valve stem is in the up position. Isn't this normal? From the FSM, pp 5-22 to 5-23, it looks like you only need to clamp the stem into the up position if doing pressure bleeding. For gravity and pedal bleeding, it does not look like this is necessary.
I did pedal bleeding. I believe the stem is still in the up position but I will check tomorrow. I took the photo above before bleeding the brakes last week.
It sounds like you are recommending I clamp the stem up regardless of how I bleed the brakes again - I just want to be sure I understand.
With the engine off, should I be able to move the stem? The manual says not to use a rigid clamp or any tool to depress it, but possibly that is only if it won't move?
Hopefully they are ok for now. I've reinstalled them with light drag and loosened the e-brake until I get this situation sorted.
The combination valve stem is still in the up position. I can wiggle it a bit, but that is it - it does not want to move downward and presumably we don't want it to. Challenger RTA, thanks for the pic of the tool used to prevent it from going down during bleeding.
I received a booster pushrod guage today so hopefully that will help me determine whether the pushrod is not adjusted outward enough.
The combination valve stem is still in the up position. I can wiggle it a bit, but that is it - it does not want to move downward and presumably we don't want it to. Challenger RTA, thanks for the pic of the tool used to prevent it from going down during bleeding.
I received a booster pushrod guage today so hopefully that will help me determine whether the pushrod is not adjusted outward enough.
pschlosser
Well-Known Member
fyi, "drum condition" is measured by inside diameter. as in, how much meat (metal) is still left inside the drum to grind against the brake shoes.
with the expectation of the "out of round" condition, where one feels the brakes pulsating braking from higher speeds when its more oblong than round, pits, surface rust, grooves, etc, are all acceptable on the brake drum, as long as the inner diameter is small enough the brake shoes can reach it.
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heminut
Well-Known Member
Those drums are pretty rough looking. I would invest in a new pair of drums myself!
OK - thanks. I will get the inside diameter checked asap. No point in having new shoes and worn out drums. I will have to check out prices on new ones - apparently basic parts have been getting hard to find. Hopefully not these.
heminut
Well-Known Member
Rockauto to the rescue again! Thanks!
Steve340
Well-Known Member
One thing is brake drums turned oversize is they are paired with oversize shoes. The lining is thicker to compenstate.
The other thing is it will pay to have the shoes radius done to match the drum to aid bed in. This can only be done by a reputable brake speciaist on a special machine.
The other thing is it will pay to have the shoes radius done to match the drum to aid bed in. This can only be done by a reputable brake speciaist on a special machine.
Katfish
Well-Known Member
I'll go against the grain and suggest not spending too much time on the rear drums.
99% of the time these cars suffer from rear brake lock-up before the fronts.
I fought this forever, smaller WC, smaller pads, etc.
The fronts provide 80% of the braking, you could cap off the rear hydraulics and probably wouldn't even notice much difference on a typical car driven on the street.
99% of the time these cars suffer from rear brake lock-up before the fronts.
I fought this forever, smaller WC, smaller pads, etc.
The fronts provide 80% of the braking, you could cap off the rear hydraulics and probably wouldn't even notice much difference on a typical car driven on the street.
heminut
Well-Known Member
Until you have to jamb on the brakes on a slick road and end up facing the direction you were coming from!
Katfish
Well-Known Member
Yep, that's exactly what happens when the rears lock up 1st.
Thx for agreeing
My whole point, is to concentrate on the brakes that do 80% of the work.
Thx for agreeing
My whole point, is to concentrate on the brakes that do 80% of the work.
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