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Ok guys. Im going to manual brakes. I currently have drums frt./rr and will continue to do so unless I see unfit. For now I wanna just go to maual.
Im using a dorman 1 in. bore stock replacement which from what I have rear inch should produce enough pressure to be happy on the street.
IM buying a CPP pushrod kit.
My big question is can I use my stock proportioning valve going from power to manual ? Or should I get an earlier distribution block and run a prop valve to the rear.
is there anything I need for the fire wall from going to power to manual or will it just bolt up ?
Last edited by coppercutlass; July 1st, 2018 at 04:57 PM.
My big question is can I use my stock proportioning valve going from power to manual ? Or should I get an earlier distribution block and run a prop valve to the rear.
Four wheel drum brakes do not use a proportioning valve. Your stock brakes should have a distribution block and nothing else. If not, someone has screwed with it.
Joe P thats what i wanted to know. Thank you guys for the info. As far as pushrod length goes. Whats the stock length? Do i jusy make sure the rod sits firm and thats it ? And of course the correct slot on the pedal
Joe P thats what i wanted to know. Thank you guys for the info. As far as pushrod length goes. Whats the stock length? Do i jusy make sure the rod sits firm and thats it ? And of course the correct slot on the pedal
The upper hole on the pedal is for manual brakes, lower for power. You have to really force the pushrod to get to the wrong hole - the angle will be off.
I would recommend going to a smaller bore if you can.
This will give you more brake pressure with less foot.
I run Wilwood disc all the way around with 3 piston calipers and a 7/8 bore.
It has a feel closer to vacuum assist than the old manual brakes.
I did run a prop valve for adjustment, no block.
I would recommend going to a smaller bore if you can.
Just keep in mind that hydraulic systems are like a lever. Making the bore smaller reduces force but increases pedal travel. If you do go with a smaller bore, be sure to keep the brakes properly adjusted. If the pedal has to travel too far, you may run out of stroke.
Im gonna go stock for now. Something tells me i will be ok considering i had a pretty big cam and weak power brakes. I drove it like that for ever. Im not stranger to foot force lol. If i dont like it then i will go willwood . I know mopar has a stock 15/16 master but dont know if it will work on a gm
Finally did it. I bout the correct derby hat and pushrod from inline tube. was wortht he extra money. I just want to make sure I Installed it correct. I adjusted the pushrod and so far the pedal feels good after bleeding. Wont be able to drive it for another month or so but I can really hear the brake engaging . Hopefully this works out good. I did buy the correct drum drum 1 in. bore master.
Im revisiting this thread. So im using the raybestos 1 inch bore master or dorman I forget which one. The brakes feel OK but it could be better. My question is to anyone how has possibly ran a 7/8 master from a monza. Will this master cylinder work on the A body ? Im still running drums all around. I know this sounds kind of dumb and a waste of time but I went to manual drums from power ( due to engine) and just set them up like stock with the 1 inch bore that's usually suggested. They work but not exactly what im used to. I wouldn't mind a little more travel on the pedal if that meant more stopping force. I want to try the 7/8 bore master. From raybestos its only 60 bucks . and if I don't still like the brakes I can go to a front disc set up and I can add the prop valve and residual valves and what not and keep the same master cylinder. The master cylinder in question is for drum/drum so in theory it should work. Or so I think.....
FWIW-
I've had Manual front disks/rear drums on my last two cars (66 442 & 68 Chevelle)... I tried a couple oem spec'd 1" bore MC's initially but found them spongy, and did not like the feel.
I tried a 1-1/8" bore master that was supposed to be for power brakes... and the feel and stroke is PERFECT.
Its firm like it should be, but not overly hard either. Definitely not spongy or touchy. Love the feel.
But thats for Disk/Drum with a prop valve. Not sure what drum/drum would feel like with that same setup.
I actually like a soft pedal 3/4 and then firm the last section of the ride. My last power drum set up wa that way and I liked it. My current 1 in ..bore is firm just a little too firm and i feel the pressure applied could be a tad higher for the amount of effort put into it. From what i read thr 7/8 bore should soften up the pedal and increase the pedal travel but gain more brake pressure. From what i understand atleast
A small bore will apply higher pressure, less volume of fluid moved.
Manual brakes may require more travel or volume of fluid moved pending adjustment.
Pedal softness is a total different thing.
Some how volume required and pressure need to balance.
Think of it like a bike pump small bore is for high pressure tires.
Large bore fills fast but lower pressure.
Im going to order it and swap it in the spring. Doing ine thing at a time here on the upgrade. I will eventually go wilwood dynalites on the front as they work woth my drum soindles but that won't ve for a while ..i just wanna make my current braking situation a little bit better. Thanks for the advice 69455.
So I did some searching and found out the raybestos MC39027 is a common alternative for wilwood's 7/8 bore master cylinder. I plan on buying it and trying it out. 45 bucks on amazon cant beat it lol. One thing that makes this master ideal for me is its for a drum / drum set up.
Now will the drum wheel cylinder bore size be different between power and manual drums ? I went from power drums to manual drums but didn't think about the wheel cylinders until right now.
I have one more question. I have the inline tube rod and derby hat set up. It seems like adjusting it is pretty straight forward but for those who have used a stock style set up for manual brakes the adjustment is pretty much removing the slack out and placing the clevis on the top hole for manual brakes on the pedal ?
July 1st, 2018, 04:52 PM
