Barely any Brakes

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plumkrazee70

plumkrazee70

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I have a 1970 Dart 340 with manual drums all around. 8 3/4 SBP.

I finally finished my 340 build and got the cam broke in. I bled all the brakes and the pedal is easy to push but has very very little braking force.

I can put the car in reverse and it will slowly roll back while at idlewith the brakes to the floor! The car will eventually stop, but it takes some serious pedal travel.

I was getting fluid to each drum, when I bled the brakes and I'm sure I got all the air out of the lines.

Each wheel cylinder, shoe, drums looked good. I'm leaning towards the MC needing to be replaced.

Just needed some advice. Thoughts?

Thanks.
 
I'll guess that you adjusted the adjusters correctly so that they are causing the shoes to lightly drag on the drums. If so, then yes, it is probably time for a rebuild or replacement of your master cylinder. Did you remove the master cylinder and empty it? If so, then did you bench bleed it before reinstalling?

You could have a friend push down on the brake pedal while you are looking into the master cylinders reservoir. If you see fluid trying to squirt up while the pedal is moving, then the seals are shot in it.
 
68gtxman said:
I'll guess that you adjusted the adjusters correctly so that they are causing the shoes to lightly drag on the drums. If so, then yes, it is probably time for a rebuild or replacement of your master cylinder. Did you remove the master cylinder and empty it? If so, then did you bench bleed it before reinstalling?

You could have a friend push down on the brake pedal while you are looking into the master cylinders reservoir. If you see fluid trying to squirt up while the pedal is moving, then the seals are shot in it.
Click to expand...

That's good sound advice! :burnout:
 
It's not clear to me if you have a pedal, and it sinks to the floor?

If so, either a leak somewhere, or bad master --is bypassing internally

Or never had a pedal, and even after bleeding it went to the floor right away?

If the last, could be air, could be shoe adjustment, or possibly a bad master

Adjust the shoes up TIGHT so you cannot turn the wheels. Now see if you get a higher, fairly hard pedal. (Pedal firmness on power brakes can be subjective, as the power booster adds a certain amount of "mushy" to the feel)
 
67Dart273 said:
It's not clear to me if you have a pedal, and it sinks to the floor?

If so, either a leak somewhere, or bad master --is bypassing internally

Or never had a pedal, and even after bleeding it went to the floor right away?

If the last, could be air, could be shoe adjustment, or possibly a bad master

Adjust the shoes up TIGHT so you cannot turn the wheels. Now see if you get a higher, fairly hard pedal. (Pedal firmness on power brakes can be subjective, as the power booster adds a certain amount of "mushy" to the feel)
Click to expand...

I'm sorry I left out a few key things. The car has manual brakes with drums. I have not driven the car since I got it , it was trailered home cause the originally motor had problems, built the 340, now moving on so I can at least drive it.


I did not yet adjust the shoes, have only bled the brakes. I've always had a pedal its just barely providing any braking. I should adjust the shows first and go from there.
 
I did not yet adjust the shoes, have only bled the brakes. [/QUOTE]

And your wondering why you have no brakes ? :smilebox: :D
 
On older cars and trucks you would be surprised how many lines are partially plugged.
 
Johnny Dart said:
I did not yet adjust the shoes, have only bled the brakes.
Click to expand...

And your wondering why you have no brakes ? :smilebox: :D[/QUOTE]
I feel like a fool. :violent1:

I will adjust and report back. I don't have much experience with drum brake applications.
 
plumkrazee70 said:
And your wondering why you have no brakes ? :smilebox: :D
Click to expand...
I feel like a fool. :violent1:

I will adjust and report back. I don't have much experience with drum brake applications.[/QUOTE]

Just funning with you...Get yourself a nice factory service manual.
Will really help in the long run.
 
The way I adjust shoes is to take them up tight, which I normally do, anyhow when bleeding to eliminate shoe adjustment in the "pedal feel." After bleeding, you should have a nice, high, hard pedal. Barely any movement from relaxed at top to "full foot pressure."

Next, slack off the adjusters a little at a time, trying to turn the wheels. As you get them to turn, slack off a little and stop when they "scrape" just a little going around. With experience you can tighten them off and then back off each "the same amount" of clicks. This is different between manual and self adjusters because the teeth are finer on the adjuster wheel.
 
Also when I bleed the brakes, start at the passenger rear, then the drivers rear.
Passenger front, drivers front.
I open the bleeder, have some one slowly push the petal to the floor, shut the bleeder.
I do not "pump" the brakes.
 
67Dart273 said:
The way I adjust shoes is to take them up tight, which I normally do, anyhow when bleeding to eliminate shoe adjustment in the "pedal feel." After bleeding, you should have a nice, high, hard pedal. Barely any movement from relaxed at top to "full foot pressure."

Next, slack off the adjusters a little at a time, trying to turn the wheels. As you get them to turn, slack off a little and stop when they "scrape" just a little going around. With experience you can tighten them off and then back off each "the same amount" of clicks. This is different between manual and self adjusters because the teeth are finer on the adjuster wheel.
Click to expand...

How do you back off the adjuster with drum on? The wheel only goes one way. What am I missing?
 
With the drum off, so you can "learn" what you are doing, you have to use a tool or extra screwdriver to lift the ratchet off the wheel. Usually, you can stick a small driver in there at the right place and push almost directly outward to release the ratchet. I actually haven't done this in several years, and different cars are a little different. A small flashlight helps.

In the photo, you have to push the adjuster lever "out toward you" looking at the photo

drum_06.jpg
 
1968FormulaS340 said:
Exactly. I have no sympathy for those that build power before they build something that can control that power.
Click to expand...

I didn't build the 340 for power. It is basically a stock rebuild. Its only a street car for cruising.

Thanks for the ignorant, un helpful post to this thread.



67Dart273 Thanks for the help, got the brakes adjusted last night and they stop much better.
 
I have to agree with 1970duster time for a up grade to disc brakes.The drum brakes were barely adequate back when new i wouldn't risk an accident because i lost my braking do to brake fade and or old out dated drum brakes.
 
plumkrazee70 said:
I didn't build the 340 for power. It is basically a stock rebuild. Its only a street car for cruising.

Thanks for the ignorant, un helpful post to this thread.
Click to expand...

Hey man, we're not trying to come off as A-Holes/D!cks. We're only trying to help you. A Front disc brake upgrade is (be it a SBP or BBP) will greatly decease braking distance vs drums. Again, I'm trying to come off as being mean, but I want you to think about this.

Let's say you're crusing along doing the speed limit (its a very nice day), when a little kid jumps out infront of you chasing the ball that went into the street. Its a full blown panic stop moment, one system will have a shorter stopping distance, the other a longer stopping distance.
Or to put it another way, one system will have your heart in your throat and instant rage at the parents for not watching their child. The other will have your car seriously damaged, the police arresting you, insurance company fighting you on getting the car fixed, two grieving parents who are suing the unholy **** out of you, a crap load of attorney fees, and probably a lot of bills from a therapist that you've been seeing to help you get over the kid you hit/killed with your car.
God help you if hit a kid or adult with any type of disability.

Again, we're not trying to be A-Holes here, we're only trying to help. In my case, my car (1970 Duster) came with front wheel drum brakes, 9" if I remember correctly, just like yours. The very first thing I did to that car was swap in a front disc brake system.
 
d5667 said:
On older cars and trucks you would be surprised how many lines are partially plugged.
Click to expand...


Sounds like the original poster adjusted the brakes and they are better.

But.....a co-worker has a 73 340 4 speed Dart Sport that was painted 20 yrs ago. ($8000 paint job on a rust free NC car back then) It's been sitting ever since. It kills me that a car so nice has just been sitting waiting to be reassembled, it's so close. I spend a day or evening every now and then helping him to get it back on the road. Last time over there we attempted to bleed the brakes. We ran into a problem and I finally figured out the front flex hoses were blocked. This was after we removed, disassembled, cleaned, and reassembled the distribution block. We reamed out the steel portion of the hoses that were blocked with rust and were able to get all 4 working. I tried to talk him into buying new hoses but he's anal about keeping the original stuff.

Haha, I tell him he still has to do the fuel system. Parked with a full tank 20 years ago. Yucchh!
 

We reamed out the steel portion of the hoses that were blocked with rust and were able to get all 4 working. I tried to talk him into buying new hoses but he's anal about keeping the original stuff.
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Yikes! Give me a call when your friend hits the road with rotted soft and hard brake lines; I want to be somewhere else off the road.

After ten years, soft lines are at their safe limit and need to be replaced even if they look good. If hard lines have rust in them they need to be replaced as brake fluid absorbs and holds moisture even if the car has not been driven causing soft sections to form undetectable from visual inspection.

If it were my car, and family riding it that car, all brake parts and lines would be replaced excepting drums and or rotors. Correct factory fresh master cylinders and soft lines are available to keep car original. One vender is Year One, I won’t post a hot link because their new site sucks at locating parts, have fun finding what they have.
 
I agree with the OP that the comments "need disk brakes" are getting repetitive and unhelpful. Does anyone really think that well functioning drum brakes cannot skid the tires easily or keep the car from rolling in reverse?

You said the shoes and drums looked good. Do they look brand new? It could be they are and just need some use to seat the shoes to the drums. Verify that for each set, the aft shoe has a longer lining than the fwd shoe (OK if they are the same, but should match left & right sides). Since you bled the brakes, it sounds like fluid is flowing thru all the tubes and hoses. If the pedal is not sinking as you hold it, and it well away from bottoming out (piston in MC bore), I think the MC is good. It is possible for the rubber hoses to degrade inside and clog the flow as you press the pedal hard. Rare, but some have experienced that. The "distribution block" in your car should be just that, with an imbalance warning switch. Make sure it is correct and that nobody swapped in a "combination valve" for disk-drum cars (has internal proportioning and metering valves). Worst-case, start disconnecting tubes and blowing thru with air to verify. You did "bench-bleed" the MC first I assume. If not, it is full of air bubbles and won't work right. Search youtube for many videos.
 
KosmicKuda said:
Sounds like the original poster adjusted the brakes and they are better.

But.....a co-worker has a 73 340 4 speed Dart Sport that was painted 20 yrs ago. ($8000 paint job on a rust free NC car back then) It's been sitting ever since. It kills me that a car so nice has just been sitting waiting to be reassembled, it's so close. I spend a day or evening every now and then helping him to get it back on the road. Last time over there we attempted to bleed the brakes. We ran into a problem and I finally figured out the front flex hoses were blocked. This was after we removed, disassembled, cleaned, and reassembled the distribution block. We reamed out the steel portion of the hoses that were blocked with rust and were able to get all 4 working. I tried to talk him into buying new hoses but he's anal about keeping the original stuff.

Haha, I tell him he still has to do the fuel system. Parked with a full tank 20 years ago. Yucchh!
Click to expand...
Good Grief man that paint job wont look so good wrapped around a tree!
 
Disks vs drums

Some on here are talking like it's completely unsafe to back out of the garage.

GEEZUS

My 69 383 RR had drums all the way around, and I never hit a thing with that car

My 64 426 had drums and I never hit anything with IT

My old 62 Landcruiser when it was 340 powered was about half dangerous, and I never managed to hit anything AT SPEED. Off road was another matter, but had nothing to do with good/ bad or drum/ disc brakes

Drums DO fade quicker. Depending on drum size, weather, and speed, they stop just as good as discs if they are on an equal maintenance basis, UNTIL they get heated and fade.

Drum brakes ARE critical for maintenance. If the drums are worn, or have been turned too far oversize, this effectively makes the shoes "a smaller circle" than the drum diameter, so the shoes only "hit" in part of the shoe lining, which quickly caues problems. Not only do you reduce the friction area, but the lining that IS doing the work quickly becomes glazed and less effective.

Drums MUST be turned or replaced when worn at all, or the shoes will not seat "flat" against the surface. They must be initially, and must be KEPT properly adjusted, hence the "self adjuster" was invented.
 
67Dart273 said:
Disks vs drums

Some on here are talking like it's completely unsafe to back out of the garage.

GEEZUS

My 69 383 RR had drums all the way around, and I never hit a thing with that car

My 64 426 had drums and I never hit anything with IT

My old 62 Landcruiser when it was 340 powered was about half dangerous, and I never managed to hit anything AT SPEED. Off road was another matter, but had nothing to do with good/ bad or drum/ disc brakes

Drums DO fade quicker. Depending on drum size, weather, and speed, they stop just as good as discs if they are on an equal maintenance basis, UNTIL they get heated and fade.

Drum brakes ARE critical for maintenance. If the drums are worn, or have been turned too far oversize, this effectively makes the shoes "a smaller circle" than the drum diameter, so the shoes only "hit" in part of the shoe lining, which quickly caues problems. Not only do you reduce the friction area, but the lining that IS doing the work quickly becomes glazed and less effective.

Drums MUST be turned or replaced when worn at all, or the shoes will not seat "flat" against the surface. They must be initially, and must be KEPT properly adjusted, hence the "self adjuster" was invented.
Click to expand...

Well said, thank-you 67Dart273...
 
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