Author Topic: Front drum brake questions...rambling....variou thoughts.....  (Read 16761 times)

Offline shadango

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Front drum brake questions...rambling....variou thoughts.....
« on: August 17, 2009 - 11:38:36 AM »
I have some pulling in my front drum brakes (10") , especially when they heat up.....grabs left.

I went over the brakes breifly and they are dry and clean, scuffed the drum surfaces a bit....new front hoses....bled the system....new master cylinder....all new fluid....still pulls.

So I figure maybe its a hanging wheel cylinder when the system heats up....?  I was going to just swap ou tthe shoes and have the drums cut to see but heck while I have it all apart might as well replace the cylinders too....

Thing is, they are $30 each.....replace the front ones, add new shoes and drum resurfacing and it'll be about $120 or so.....

But I have been thinking of swapping to disk brakes in the front...i know aftermarket setups are pricey (though worth it I am sure)......

Thinking of going with a stock setup if I can find parts....that means spindles, calipers, rotors, etc....plus a new master cylinder, right?

BUT......my engine makes little (7-9 in HG) vacuum.....so i would need a full time vacuum pump for the car, right?  Those run a few hundred I think.... :pullinghair:

Or can you run non-power front disks?

All in all that ends up being a lot of cash at once.

So getting the drum brakes smoothed out may be the best bet for now....or is it?

Need some feedback and thoughts.....There is this one hill that I drive on sometimes and its a long downgrade with a light at the bottom...It taxes even my Durango's power 4-wheel disks sometimes and teh brakes on my motorcycle....The otehr day, in the Barracuda, I was using both feets on the pedal at the light and she still wanted to move just a bit....so I guess they were so hot they were fading.....Other that the pull, the brakes work fine in normal traffic.....




Offline Changin Gears

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #1 on: August 17, 2009 - 12:31:01 PM »
Non-power disc is the way to go.  That's all I run, nice firm pedal.  Only your grand-mother needs power, maybe not.


The goal never changes - Stop the 60' timer with your back tires

Offline Bluemonster71RT

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #2 on: August 17, 2009 - 12:41:14 PM »
I had 4 wheel manual drum and switched to 4 wheel disk and plan on keeping it manual unless it's still a pump pump skid situation.
But as far as front disks, depending on the kit you get you reuse your drum spindles.
1971 Challenger RT 383 4spd

Offline shadango

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #3 on: August 17, 2009 - 12:41:26 PM »
I wouls still need a different m/c though, right?  Right now I have the m/c with two equal sized sections...I think disk I would need the m/c with larger front?

Offline shadango

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #4 on: August 17, 2009 - 12:50:35 PM »
I had 4 wheel manual drum and switched to 4 wheel disk and plan on keeping it manual unless it's still a pump pump skid situation.
But as far as front disks, depending on the kit you get you reuse your drum spindles.

Looking through some old threads it looks like 73-up drum spindles are the better thing to have?  :clueless:

Could I switch over my 72 spindles to disk without breaking the bank?  My feeling is why sink $120 into drum brakes when I can put that towards disk.

I figure a reman disk brake m/c is cheap....can I get disks, calipers etc from a parts store and make this work?  Would I also need new hoses (just bought mine for the drums... :banghead:  )
« Last Edit: August 17, 2009 - 12:52:50 PM by shadango »

Offline 67vertman

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #5 on: August 17, 2009 - 01:26:32 PM »
I saw this set up, and it is pretty resonable.  I think the rotor are 10.50, I sent them two emails and they haven't responded on the size of the rotor.  I want 11.75 since I will have a big block in my car.

http://performanceonline.com/store/customer/product.php?productid=19537&cat=1294&page=1



Ron - Born and raised in Southern California

I got the 1970 Cuda, but still need the hot blonde to ride shotgun!

First car -1969 Road Runner 383 4sp

Current ride - 1970 Barracuda 440-6 4 sp Dana 60  (4:10)

Offline shadango

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #6 on: August 17, 2009 - 05:09:11 PM »
Kind of generic descriptions, eh?

Like, are they vented rotors? Single or dual piston calipers?  Size of rotors? How hard is it to get replacements pads, rotors, etc?

Seems like the spindles would be the biggest expense...if I can find a way to do the same thing using my stock spindles I would like to.....although I need to pull the spindles at some point anyways so I can replace the boots on the balljpints...they are shot....balljoints are fine though.  :banghead:

Offline cudazappa

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #7 on: August 17, 2009 - 05:41:55 PM »
cheapest way to go, get some 73+ B/R/FJM spindles with the 10.87 slider caliper adapters.  Rotors and calipers are dirt cheap.  Run a manual disc brake MC (larger reservoir is in the rear, btw) and you should be all set...
1971 Challenger - AutoX project
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Offline Bluemonster71RT

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #8 on: August 17, 2009 - 05:47:37 PM »
Both my kits are SSBC kits.  It says that the rotors and pads are stock replacments for the front and the rear are from a Pffford set up Thunderturd I think.  As far as the mater I have not investigated on if I need a bigger one since deciding to go rear disk. I bought the manual kit for the front and all I have to do is use the push rod that they gave me.     
1971 Challenger RT 383 4spd

Offline HP2

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #9 on: August 17, 2009 - 05:56:46 PM »
used disc spindles from the junkyard $40 pr
used caliper adapters from junkyard $40 pr
new rotors from rock auto $75 ea
rebuilt calipers $45 ea
new pads $25 pr
rebuilt master cylinder $35
adjustable push rod $35

Disc brakes for $415.

If the budget is even tighter, well, you can scrounge the yard for rotors that still have some meat on them or pick up calipers that still have moving pistons with decent pads in them. This isn't going to give you world class braking, but it will put a set of 10.87 rotors under the nose of your car without busting the bank.

Offline 72rtchallenger

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #10 on: August 17, 2009 - 08:18:16 PM »
73 a body spindles will work for your upgrade,,i found a used set for mine and they worked perfect

http://www.moparaction.com/Tech/archive/disc-main.html
72rtchallenger
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Offline shadango

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #11 on: August 18, 2009 - 07:00:55 AM »
cheapest way to go, get some 73+ B/R/FJM spindles with the 10.87 slider caliper adapters.  Rotors and calipers are dirt cheap.  Run a manual disc brake MC (larger reservoir is in the rear, btw) and you should be all set...

I would need splash shields and proprtioning valve too, right?

Can someone clue me in on what the "10.87" refers to?  I assume its a measurement..overall length maybe? :clueless:

Offline HP2

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #12 on: August 18, 2009 - 08:45:01 AM »
You can get by without splash shields pretty easily, but if you doing the salvage yard scrounge, you can also find them easy too. Proportioning valve is also a maybe, depending on the master cylinder split. I've converted cars that had pretty good balance without a change, some locked up the rears so quick that they needed a change. Again, if you've found a donor car, snag the prop valve along with it any other parts your taking and you'll have it if you need it.

10.87 refers to rotor diameter. Mopar has two sizes, 10.87 and 11.75. The smaller ones are abundantly available on a large number of cars built from the early 70 to the early 80s. The bigger ones appeared around the mid seventies on B bodies and carried into the 80s on four door, heavy duty, and police applications. Prior to 73, there were big and msall bearing rotors and their matching spindles. After 73, all the rotors will interchange on all the spindles, but the big rotors do require a bigger caliper bracket and 15" wheels to clear everything. Needless to say, larger rotors provide greater braking which is why so many new cars use 13" rotors inside their 16 and 17 inch wheels.

Offline cudazappa

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #13 on: August 18, 2009 - 09:16:15 AM »
There are 2 versions of the 10.87" rotor, the 70-72 B & E body, small inner bearing, and the 73-89 A,B,E,F,J,M rotor with the large inner bearing.  The 11.75" rotor was used on 76-81 B and R bodies, the use the same large inner bearing as the later 10.87" rotors.  Cop cars got 11" rear drums, there was no deviation in rotor size.  Pin type calipers were used on the 70-78.5 B and E bodies.  In Late 78 they switched over to slider calipers.  All 73+ A,F,J,M use slider calipers.
« Last Edit: September 02, 2009 - 06:22:02 PM by cudazappa »
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Offline shadango

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Re: Front drum brake questions...rambling....variou thoughts.....
« Reply #14 on: August 18, 2009 - 09:37:14 AM »
So it looks like the big bearing, short height spindles from a yard are the best way.....with the big brackets, rotors and calipers....

Seems like the link goes to smaller stuff...I figure if I am going to do all that, might as well go with the big rotors for better braking.

Ok, I think I am straight now...LOL

Of course, now the  14" spare tire/wheel I picked up cheap and modified to fit my drum car wont work when I switch...LOL

I have aftermarket 15" wheels right now...they should fit?

And 'slider' type calipers are preferred, right?
« Last Edit: August 18, 2009 - 09:45:49 AM by shadango »