"Black Dahlia"
- Thread starter tfeverfred
- Start date
fletcherson
Well-Known Member
I learned to do them early on, as one of my first jobs was a "mechanic" at a cab company. Brakes, tires, batteries, pumps, transmissions....dirty work, all day long. Many of the failures are due to adjusters not being correctly installed and not having the shoes adjusted tight enough initially. They also require adjustment on occasion, especially if you don't use reverse much as that's how they self adjust, or are supposed to.
tfeverfred
Well-Known Member
Fletcherson, could you please explain how going in reverse allows the brakes to self adjust? I've heard of it, but never understood it.
JeffK
Member
Here's a quick explanation, I learned this in Auto Shop in HS but that was about 37 years ago lol. I had to look up why out of curiosity.
Bendix/Wagner
The Bendix/Wagner self-energizing brake has a single anchor pin located above the wheel cylinder. The primary shoe is identified by its length and position on the shoe. The lining segment is shorter than the lining segment on the secondary shoe and is positioned toward the adjuster or heals of the shoe. When the brake is applied, the master cylinder applies hydraulic pressure to both wheel cylinder pistons.
The primary and secondary shoes engage the friction surface of the drum. The wrapping motion of the primary shoe transfers pressure through the adjusting screw and drives the secondary shoe against the anchor pin and friction surface of the drum.
The secondary wheel cylinder piston is held in its rest position as the secondary shoe is driven against the anchor pin.
The adjuster mechanism is attached to the secondary shoe. It is a mechanical device that is made up of the three components.
First, an adjusting screw that is a threaded device like a nut and bolt. The head of the bolt is a notched wheel with a cylindrical pin. A washer and slotted cap fits over the pin and engages web section of the secondary shoe. The nut is also a slotted cap that threads onto the bolt and engages the primary shoe.
Second, a lever moves on a pivot to engage and turn the notched wheel.
Third, a cable or linkage is attached to the lever and the anchor pin to move the lever at its pivot point. There are springs and retainers to hold the mechanism in place.
The adjustment takes place when the vehicle is in reverse and the brakes are applied or when the parking brake is engaged. The cable or link attached to the anchor pin pulls the lever mechanism based on the movement of the secondary shoe.
When the brakes are applied, the lever cannot move the adjuster screw because the brake pressure is being used to apply the shoes. The adjuster lever mechanism must store the adjustment and turn the notched wheel when the brake is released.
There are two types of Bendix/Wagner self-adjusters. Type 1 uses a cable attached to the anchor pin and hook that is attached to the adjusting lever. A guide holds the cable in place. A spring connects the lever to the primary shoe to contain the adjuster. Type 2 uses a cable attached to the anchor pin with a spring and guide that attaches to the lever.
Bendix/Wagner
The Bendix/Wagner self-energizing brake has a single anchor pin located above the wheel cylinder. The primary shoe is identified by its length and position on the shoe. The lining segment is shorter than the lining segment on the secondary shoe and is positioned toward the adjuster or heals of the shoe. When the brake is applied, the master cylinder applies hydraulic pressure to both wheel cylinder pistons.
The primary and secondary shoes engage the friction surface of the drum. The wrapping motion of the primary shoe transfers pressure through the adjusting screw and drives the secondary shoe against the anchor pin and friction surface of the drum.
The secondary wheel cylinder piston is held in its rest position as the secondary shoe is driven against the anchor pin.
The adjuster mechanism is attached to the secondary shoe. It is a mechanical device that is made up of the three components.
First, an adjusting screw that is a threaded device like a nut and bolt. The head of the bolt is a notched wheel with a cylindrical pin. A washer and slotted cap fits over the pin and engages web section of the secondary shoe. The nut is also a slotted cap that threads onto the bolt and engages the primary shoe.
Second, a lever moves on a pivot to engage and turn the notched wheel.
Third, a cable or linkage is attached to the lever and the anchor pin to move the lever at its pivot point. There are springs and retainers to hold the mechanism in place.
The adjustment takes place when the vehicle is in reverse and the brakes are applied or when the parking brake is engaged. The cable or link attached to the anchor pin pulls the lever mechanism based on the movement of the secondary shoe.
When the brakes are applied, the lever cannot move the adjuster screw because the brake pressure is being used to apply the shoes. The adjuster lever mechanism must store the adjustment and turn the notched wheel when the brake is released.
There are two types of Bendix/Wagner self-adjusters. Type 1 uses a cable attached to the anchor pin and hook that is attached to the adjusting lever. A guide holds the cable in place. A spring connects the lever to the primary shoe to contain the adjuster. Type 2 uses a cable attached to the anchor pin with a spring and guide that attaches to the lever.
fletcherson
Well-Known Member
The adjusters are activated by a lever (the lever that acts as a ratchet when you adjust the shoes) that spins the adjuster when the vehicle stops in reverse because of the way the shoes move. Some have a cable that activates the lever, some just secure it to one shoe. If the adjuster is installed in the wrong direction or the lever on the wrong shoe, it will loosen, not tighten and allow the shoes to back away from the drums rather than remain in contact. It's a crude, but ingenious solution, and works pretty good as long as the adjusters don't seize or the car doesn't reverse often enough to overcome the normal wear on the shoes.
fletcherson
Well-Known Member
Oops, I replied from the initial reply, sorry for the duplicate description, I didn't see it.
tfeverfred
Well-Known Member
Thanks, guys. Learned something today.
tfeverfred
Well-Known Member
Picked up a set of Speed Bleeders for the front discs and installed them. The set for the rear drums will be here Friday. Found them at O'Reilly's. Part #12702 for the disc's and #12705 for the drum brakes.
tfeverfred
Well-Known Member
Got the day off and got bored. So, I decided to mount the tabs for my fuel line. I'll be running 3/8" metal line, so I installed 4 tabs. Not much, but it's something. In hind thought, I may move up to larger size tabs, so I can run the + battery cable in the same route.
Gerry
Well-Known Member
As much as I want to hold back, running a battery cable and a fuel line close together/ in the same clip, is not a good idea. Any problems with the battery cable going to ground near a fuel line is a recipe for disaster. Check out some regs for racing and see what they say about this set up.
EX JUNK
Moderator
tfeverfred
Well-Known Member
Good advise. Can't believe I didn't think of that.
And..... why would you want to hold back on good advise, especially a safety issue?
old round fart
Well-Known Member
Use the same bolt with another clamp going the other way.
tfeverfred
Well-Known Member
Now, THAT is an excellent idea. Thanks!
One of the reasons I'm confronting things like this, is because of my first build. There were a LOT of things I didn't plan and the results were poor, quick solutions to problems. Going at a slower rate this time, is giving me a chance to fix those early mistakes and build a better car.
I'm not sure I've formally said it before, but.... if ANYONE sees something that needs to be addressed, by all means, let me know. I love T Buckets, but I'm NOT a master builder of them. I do appreciate constructive discussions.
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If you are wanting a 2nd opinion, then you are ugly too!!!
Look out, Rick. Your mug is on facebook, too!
tfeverfred
Well-Known Member
Well...... okay then... moving right along.
Good news and bad news. Good: My Speed bleeders came for the rear and are installed. Now, I can bleed the system and check for leaks. Bad: a deal on a cheap set of wheels and tires fell through. I could probably get a set, for a fee, from the salvage yard, but being on a budget, paying would be counter productive. I'll just continue to save for what I really want.
Good news and bad news. Good: My Speed bleeders came for the rear and are installed. Now, I can bleed the system and check for leaks. Bad: a deal on a cheap set of wheels and tires fell through.
I could probably get a set, for a fee, from the salvage yard, but being on a budget, paying would be counter productive. I'll just continue to save for what I really want.
JeffK
Member
Best thing about these cars is you can pile up the parts and go at your own pace. My last set of Radius Rods is coming from Ron and I will have the rolling chassis (parts) sitting in my spare bedroom (LOL) minus shocks, 1 taillight, Intake & Carb, Transmission and rubber. Now maybe I can focus on saving for the body LOL. You are correct, buy what you want and don't compromise just to "get it done" . For me, that will be satisfaction.Well...... okay then... moving right along.
Good news and bad news. Good: My Speed bleeders came for the rear and are installed. Now, I can bleed the system and check for leaks. Bad: a deal on a cheap set of wheels and tires fell through.
tfeverfred
Well-Known Member
A friend came through with a pair of temporary spares in the bolt pattern I needed. One has a slow leak at the rim, but free, is free. Couldn't say no. A quick coat of paint and on they went. This set up is 21" and the ones I'll end up using are 26". This will make it a lot easier to move around.
