Douglas Ferguson
Senior Member
Posts: 378
Loc: Virginia
Reg: 09-12-04
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08-29-12 06:58 PM - Post#2264574
Hey guys,
Placed a big order and it arrived today. New drums all around, shoes all around, brake hardware for each wheel, rubber lines (two for front, one for rear because mine split into steel in the rear), and master cylinder (still single pot until I can afford dual with booster upgrade). I have been reading a lot of good things about the Poly Armour brake lines. What size do you recommend? I have read that 1/4 all around for drums is the way to go but I wanted to verify with you guys first. There's a lot of knowledge here, might as well tap into it! Take care guys.
http://www.autozone.com/autozone/accessories/ Misce...
66 Chevy C-10 SWB Stepside (project)
78 Chevy C-10 (Sold in 2009) |
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Douglas Ferguson
Senior Member
Posts: 378
Loc: Virginia
Reg: 09-12-04
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08-30-12 08:32 AM - Post#2264744
In response to Douglas Ferguson
1/4 it is! I will take plenty of pics and document the drum/drum brake overhaul and post it up in case anyone is interested. 
66 Chevy C-10 SWB Stepside (project)
78 Chevy C-10 (Sold in 2009) |
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Douglas Ferguson
Senior Member
Posts: 378
Loc: Virginia
Reg: 09-12-04
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08-31-12 09:07 AM - Post#2265110
In response to Douglas Ferguson
Taking a second look at things, I am going 3/16th all around. The rear line along the frame now is 1/4th, going into the old rear rubber hose as such, coming out of the brass tee as 3/16th to the rear wheels. My new rear rubber hose is setup to receive 3/8th fitting, so if I run 3/16th all around it will be less fittings, less chance of leaks. I will only need fittings to come out of my master cylinder at 7/16 and come down to 3/8 for the line, then from 3/8 to 7/16 for my front hoses. Plus, these fittings are apparently more abundant.
Lots of research says different sized lines dont effect braking or pedal feel since pressure is pressure. Will post pics and a part list when I am done in case anyone wants to do the same. Looks like new lines (poly armour) will be about 25 with the fittings included, not bad at all.
66 Chevy C-10 SWB Stepside (project)
78 Chevy C-10 (Sold in 2009) |
|
 Vaughn
"11th Year" Gold Supporting Member
Posts: 13558
Loc: Colorado Springs, CO
Reg: 08-08-04
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08-31-12 03:01 PM - Post#2265211
In response to Douglas Ferguson
Size does affect pressure. The ideal gas law states that PV= NRT, or in other words pressure times volume equals NRT, where T is Temperature, N and R equal a constant for this type of equation. Yes, it even works in hydraulic applications. If the right side of the equation is all constant (assuming temperature will be the same in both instances) - then if volume increases the pressure HAS TO drop.
If you increase the volume, you will drop the pressure in the line - particularly since your bore size is fixed in the master cylinder. If you increase the line diameter size you will drop in overall pressure.
Take a look at more modern brake systems with disks on it. The brake lines are smaller in diameter, so as to keep the pressure drop to a minimum. I've tried using larger diameter brake lines - there was a significant loss in pressure to the brakes, which caused a much longer pedal stroke.
It should be obvious - using larger volume lines requires a larger volume of fluid coming out of the master cylinder. There is a limitation with drum brakes however, you can't just use the smaller lines that disk lines do. The slave cylinders require a certain amount of volume (more than disks) and a certain amount of pressure. Just use stock diameter size lines and you will be fine.
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Douglas Ferguson
Senior Member
Posts: 378
Loc: Virginia
Reg: 09-12-04
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08-31-12 04:59 PM - Post#2265240
In response to Vaughn
Vaughn, I was looking forward to your response in particular because I have seen such a constant amount of valuable information come from you over the years, so much so that I would probably pay for it. Thank you for the advice, unfortunately I have the lines purchased and bent, all 3/16th. My main issue besides having a 12 pack of bud light in me, is routing the lines in a manner to keep them away from the headers. I will report back with pictures and any issues I may have with the 3/16th. Its cheap enough that I can replace if necessary, although it wouldnt be fun since I am already having a rough time wiggling under the truck since im 6'3" and 235lbs!
66 Chevy C-10 SWB Stepside (project)
78 Chevy C-10 (Sold in 2009) |
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Douglas Ferguson
Senior Member
Posts: 378
Loc: Virginia
Reg: 09-12-04
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09-01-12 01:00 PM - Post#2265446
In response to Douglas Ferguson
Somebody should have told me it was going to be this bad, a warning would have been nice! What should have taken me a couple hours took me a day and a half. Crawling under a vehicle to make bends is very time consuming. I will try to post pics in the next few days of the whole ordeal. Lines are ran and I am on the drum hardware now. Replacing everything with new shoes and drums. The drums are a pain also, here goes the weekend!
66 Chevy C-10 SWB Stepside (project)
78 Chevy C-10 (Sold in 2009) |
|
Vaughn
"11th Year" Gold Supporting Member
Posts: 13558
Loc: Colorado Springs, CO
Reg: 08-08-04
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09-01-12 02:53 PM - Post#2265486
In response to Douglas Ferguson
If/when you experience pressure problems, instead of replacing all the lines, you can substitute a larger bore master cylinder. You may only be able to find a larger bore master cylinder in the dual reservoir variety (look at 1 ton trucks in 67-69 that had drum/drum brakes) - which is perfectly fine. You would route the rear lines to the back reservoir, and the front lines to the front reservoir. Since it is a drum/drum truck, you wouldn't need a proportioning valve.
Yes, it will bolt in place of the single reservoir master cylinder. It is also safer, which is why vehicles after 1966 have a minimum of two reservoirs.
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Douglas Ferguson
Senior Member
Posts: 378
Loc: Virginia
Reg: 09-12-04
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09-01-12 05:24 PM - Post#2265514
In response to Vaughn
Thank you for the advice, I am going to a dual res when I go with a booster in the near future. Money and time isnt on my side much like everyone else.
66 Chevy C-10 SWB Stepside (project)
78 Chevy C-10 (Sold in 2009) |
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 hilandr451
8th Year Platinum Supporting Member and Moderator
Posts: 3623
Loc: Bakersfield, Ca.
Reg: 01-02-02
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09-02-12 09:02 AM - Post#2265694
In response to Douglas Ferguson
Vaughn, I was looking forward to your response in particular because I have seen such a constant amount of valuable information come from you over the years, so much so that I would probably pay for it. Thank you for the advice....
Yeah, we kinda like him too....  Thanks for the complement to Vaughn. A little gratitude goes a long way around here. These guys volunteer their knowledge and expertise every day just so they can help somebody they've never met with a project. That's priceless in my book!
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Douglas Ferguson
Senior Member
Posts: 378
Loc: Virginia
Reg: 09-12-04
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09-02-12 05:45 PM - Post#2265836
In response to hilandr451
Today was pretty exhausting, to say the least.
Heres the old brakes pulled, this was on two days ago. These were 1/4 to the front drums and 3/16 to the rear
This was the brass tee that was underneath the driver side directly net to a header, the line had corroded so much it just snapped when I took it out. With a single pot master cylinder this thing would have killed me on the highway. Along with the engine perches not being bolted down, all bolts finger loose on the steering gear box, three bolts in the transmission and loose, etc... but thats a story for another post!
So I decided to go with Poly Armour brake lines, pre cut and with an inverted flare with hardware attached. It was a little tricky at first figuring out what size fittings I needed and whatnot, but it wasnt too bad.
Closer look at the adapters, tees, and lines. I will post the prices and exactly what I got soon. I decided to go with all 3/16th, we will see how that works.
With the new master cylinder bolted up I had to put a 7/16 - 24 male to 3/8 -24 female inverted flare adapter for my line to feed into the master.
And heres the line up to the master before I put on the adapter. All bends were by hand, had absolutely no issues with kinking at all. Love the stuff.
Lines were ran down, will get pics soon. Here's the stock gear, ready for removal!
Wasnt too bad until I got to the bolt holding the wheel cylinder.... I wish I had more pics, but oh my god it was so hard to get this bolt out. It took me 3 hours of pushing, pulling, kicking, slamming, pounding, yanking, screaming, cussing, taking breaks, more cussing, and finally I rigged up something that I was able to stand on and it moved. Finally came out...
And heres the bolt, 40 years after it was installed!
And the old wheel cylinder.
And the new wheel cylinder! Take care to ensure the wheel cylinders depress after they are bolted, I had an issue where the cylinder was unable to because it was pressed on the backing plate...
And with new cylinder, hardware, and pads with brake grease on all friction points, and then some, lol.
With new drum as well!
New rubber and steel lines with adapter fittings...
Now to the other side!
Oh my god again. I couldnt get the drum off no matter what! I banged, hit, smacked, pried, hammered, backed the adjuster off with a screwdriver, etc... Absolutely nothing with two hours wasted. So I took the nut off the spindle and pulled the drum off with the hub as one. I then proceeded to hammer, smack with wood, pound, hit, kick, etc... Another hour wasted with nothing. Then I looked at it, and it hit me, that the damn drum was, for lack of a better word, rivited to the hub. So, I drilled out the rivets, pounded them out and the hub fell from the old drum instantly. Lesson learned!
So after that hickup, I got the driver side done as well. The front is done, now the back tomorrow. I pulled a wheel the other day from the rear and the wheel cylinder was newish, so I dont think ill have to do the rear, but I just might since im doing everything else and they are so cheap. I hope tomorrow goes better than the last few days, inm beat up, sore, and tired. But at the end I will be able to stop. Next up is steering, and maybe I will be able to drive this thing around town!
66 Chevy C-10 SWB Stepside (project)
78 Chevy C-10 (Sold in 2009) |
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hilandr451
8th Year Platinum Supporting Member and Moderator
Posts: 3623
Loc: Bakersfield, Ca.
Reg: 01-02-02
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09-08-12 10:27 AM - Post#2267657
In response to Douglas Ferguson
nice work on your '66! I had no idea they riveted the drums to the hubs! I have seen counter sunk slotted machine screws holding them on, but never rivets! Jeeze who would have thought? Pretty safe to say those are the original drums yeah?
one thing I wanted to say though, although the rusted through break line would have at the least left you in a ditch somewhere, you really need to think of safety when working on your project in your garage.
Always use jack stands, and take the time to come up with an exit strategy. A few seconds of planning could mean your life should anything go wrong.
Please don't take this the wrong way, it's just that we would like to keep you around, brother!
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Douglas Ferguson
Senior Member
Posts: 378
Loc: Virginia
Reg: 09-12-04
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09-08-12 04:30 PM - Post#2267772
In response to hilandr451
Thanks man! You are 100% correct, I need jack stands. I never got under my vehicle while it was jacked, but I did have my legs under while messing with the brake hardware... Thanks for the wake up call, I need them sometimes!
66 Chevy C-10 SWB Stepside (project)
78 Chevy C-10 (Sold in 2009) |
|
argonaut
Senior Member
Posts: 262
Loc: SoCal
Reg: 12-19-01
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12-18-12 12:36 AM - Post#2298924
In response to Vaughn
Size does affect pressure. The ideal gas law states that PV= NRT, or in other words pressure times volume equals NRT, where T is Temperature, N and R equal a constant for this type of equation. Yes, it even works in hydraulic applications. If the right side of the equation is all constant (assuming temperature will be the same in both instances) - then if volume increases the pressure HAS TO drop.
If you increase the volume, you will drop the pressure in the line - particularly since your bore size is fixed in the master cylinder. If you increase the line diameter size you will drop in overall pressure.
Take a look at more modern brake systems with disks on it. The brake lines are smaller in diameter, so as to keep the pressure drop to a minimum. I've tried using larger diameter brake lines - there was a significant loss in pressure to the brakes, which caused a much longer pedal stroke.
It should be obvious - using larger volume lines requires a larger volume of fluid coming out of the master cylinder. There is a limitation with drum brakes however, you can't just use the smaller lines that disk lines do. The slave cylinders require a certain amount of volume (more than disks) and a certain amount of pressure. Just use stock diameter size lines and you will be fine.
I hate to disagree with this, but the assertion simply isn't true. This is not a correct application of the ideal gas law, given that in a hydraulic system the fluid is assumed to be incompressible. The volume of the system is effectively constant.
The line size has nothing to do with the pressure required to create stopping force. Only the diameter of the slave cylinder, diameter of the master cylinder, and pedal ratio determine force applied at the caliper. The application of the resultant frictional force at some distance from the axis of wheel rotation creates a torque which stops the wheel.
Jason M.
64 c-10 short fleet . 67 firebird . 91 crx si . 98 zx-6r |
Edited by argonaut on 12-18-12 12:38 AM. Reason for edit: No reason given.
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argonaut
Senior Member
Posts: 262
Loc: SoCal
Reg: 12-19-01
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12-18-12 12:46 AM - Post#2298925
In response to argonaut
Also, do not use a master cylinder with a larger diameter bore if you are lacking in brake force.
Force = Pressure x Area
Since the brake system fluid is all at a uniform pressure then:
P1 (master cylinder) = P2 (slave cylinder)
It follows that:
F1 / A1 = F2 / A2
So if you want to increase F2, or the force at the slave cylinder, then you actually want to decrease A1, which is the area of the master cylinder. This means a smaller bore. But do note that going to a smaller bore master, while creating a grater force at the slave for a given pedal force, will also require a slightly longer stroke.
Jason M.
64 c-10 short fleet . 67 firebird . 91 crx si . 98 zx-6r |
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