Ok, I wanna start by saying that I have looked around at about all the threads I could find on setting up a complete braking system for a model A (Or anything for that matter) and it seems everyone is way past me and just trying to resolve "issues". I on the other hand am just about to start putting brakes on my A build and have some questions. I've heard from multiple people (Mostly on here) that you have to piece everything together to match, and just trying to make "this work with that" will almost guarantee failure. So, this is what I have... -Drums on rear (Ford Econoline rear) -Disks on front (new from Speedway) -It looks like a lot more clearance into the firewall with the pedal that swings from the top than the pedal that mounts to the frame rail, because of the shape of the pedal arm. -I'd rather not have the MC on the firewall, but I know there are kits to hide either pedal ***y MC -I've read a lot about different ratios and I'm lost, will the pedal ***y I get tell me what ratio it is or...? -How do I know what size bore to go with? -Am I safe getting about any MC/pedal kit that is for drum/disk? And using residual valves if necessary? Thanks for any help! I appreciate all the info I get...
Ok so you have the disc and drum set up. Do u have specs on the discs and calipers? They need to be matched to an appropriate master cylinder ie disc-drum type and correct bore size, also that it can contain and supply enough fluid for your system. As for pedal ratio, it depends on if u have a boosted system or not. Boosted needs less eg 5:1. Form a plan of the entire system before you get too far ahead. Get some advice from a local spe******t if you are unsure of anything. This is one area u don't want to take a guess on. Hope this helps.
As a general rule of thumb your pedal ratio should not exceed: 6:1 for manual brakes with a 1” bore master cylinder 4:1 for power brakes with a 1 1/8” bore master cylinder Here's a good link: MP Brakes
are you talking about floor(frame) mounts to make more room? also, basically bigger bore on master = less pedal travel, because it moves a higher volume of fluid in less travel of the piston. but it also gives it less overall pressure coming out.(someone else can explain that maybe im not a engineer) the smaller you go, it needs more travel to make it move the same amount of fluid. but it will make the pedal more powerful. using a disc setup in front you dont need to move as much fluid, so anything from 5/8" to 1" should be fine.
Jimbo "Do u have specs on the discs and calipers?" I don't have any specs but they are the chevy BP for 37-41 spindles from speedway. I will find the paperwork that came with them and post soon. Gator Thanks for the link! Makes that part cake!! Johnny Bondo "are you talking about floor(frame) mounts to make more room?" Yes, but I was wondering if the floor mount would ultimately be less room, or more of a pain, because of the way the arm bends back toward the firewall. I'm not sure, just guessing by what I've seen. I'm not too fond of cutting a slot in the firewall for the arm to travel through (which I've seen), but do you think I could get enough pedal without a lot of travel, to keep the arm from hitting the firewall? Thanks for the replies so far....
The "Floor" mounts are actually UNDER floor mounts that mount to the frame. The arm is mounted so that it is in front of the firewall and comes through a slot. This is the most common way to mount a brake pedal in a Hot Rod these days.
When it come to your valves, 10lb. residual valve in the rear line, adjustable proportion valve in the rear line + a brake pressure switch and a 2lb. valve for the front. If your master is on the firewall then you won't need the 10/2 valves but then you have a big ol' chunk of steel on the firewall. GOOD FUN
I like the master cy under the floor. the easy way is to order a kit. Built brake system before alot of trouble.
Thanks guys. There is a MC w/ pedal kit from speedway that I think I may get. I didn't wanna start by ordering all new stuff, but the braking system isn't something I want to "test" my luck out on. I knew about the 10/2 residual valves, but I didn't know about the proportioning valve until I read about it last night. Does anyone have pics of a under floor mounted MC from their build? And does the pedal travel through the firewall? Any other suggestions welcome, and again...Thanks!
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