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1956 F100 Conversion to Dual Master Cylinder with Stock? Booster
My truck came with a brake booster. It looks stock, but I am still new to these trucks. When researching dual reservoir master cylinders for my drum/drum setup, a lot of posts mention upgrading to a booster or staying manual. I would like to maintain the current master cylinder location/access through the floorboard hole.
I was looking at the MidFifty bracket/master cylinder but it mentions being for manual setup, will I run into trouble trying to work this in with my current booster setup?
Any info on how the hard lines would connect/flow from the master cylinder, to booster, to brakes?
My truck came with a brake booster. It looks stock, but I am still new to these trucks. When researching dual reservoir master cylinders for my drum/drum setup, a lost of posts mention upgrading to a booster or staying manual. I would like to maintain the current location/access through the floorboard hole. Was looking at the MidFifty bracket/master cylinder but it mentions being for manual setup, will I run into trouble trying to work this in with my current booster setup? Any info on how I would run the hard lines?
Whatever you decide to do I'd be interested in that set up
I've never seen one of those before. A really cool piece.
Unfortunately, I don't think it can be made to work with a dual MC. The factory MC only has one output, with a "manifold" that splits it out into three lines. The dual MC has two separate outputs. This setup looks like one way in, and one way out.
Here is another item I found relating to what appears to be instructions for "field installation" of a brake booster kit that includes the same booster:
Just so I do not lose the link, I found that installation page here:
Unfortunately, I don't think it can be made to work with a dual MC. The factory MC only has one output, with a "manifold" that splits it out into three lines. The dual MC has two separate outputs. This setup looks like one way in, and one way out.
This got me thinking...
I agree the factory setup was the single output to a three-way split as you described. 1 line to the back to be split between the rear wheel cylinders, 1 line to the front right wheel cylinder and 1 line to the front left wheel cylinder.
Now I am going completely off memory about this right now, but I believe the way things are currently setup, the single out was going to a TWO-WAY split. 1 line to the back to be split between the rear wheel cylinders and 1 line to the brake booster input and then from the brake booster output the line was then split to the two front wheels cylinders.
I will confirm the current routing on my truck later, but if this is indeed the way it is currently setup, wouldn't it work much the same with the dual master cylinder (rear to rear, front to booster)? Wouldn't having the booster only on the front line(s) also act somewhat as a "proportioning valve" with more braking from the front wheels?
Another link I found during my research that was very insightful. I provided a link to the source page, but provided the information below as well in case the site ever disappeared.
Originally Posted by Dave78Chieftain.com (also further referenced to Stovebolt.com)
As pressure is applied to the brakes, fluid is passed into the Hydro-Vac (shown in YELLOW). It by-passes the hydraulic brake piston (# 20, thanks to the check ball), and pressure goes through the lines to the wheel cylinders. At the same time it also passes through a pathway in the unit and applies pressure to (# 10) the control valve hydraulic piston. As more pressure is applied to the brakes, the control valve piston pushes up on the metal rod on the rubber diaphragm (# 7). The metal portion of the diaphragm has an air pathway through the center which allows air flow circulation throughout the unit (through the tube (# 9) to the rear of the power cylinder piston). The atmospheric / vacuum valve (# 8 and # 13) is a two part valve located above the diaphragm. It blocks air coming into the Hydrovac due to the spring (# 14) under the intake tube. Brake pressure changes cause the vacuum valve to seat on the rubber diaphragm (shown in PINK), sealing the air passage through it and effectively blocking any air coming into the power cylinder (# 1) between the ports (# 6) located in the end plate of the unit and the connecting tube (# 9).
As pressure builds and the diaphragm is pushed even further forward, the atmospheric valve portion opens (shown in PURPLE) allowing air to enter the power cylinder (air path shown in GREEN) and letting the vacuum from the engine pull the power cylinder piston (# 2) forward which pushes the hydraulic brake piston (# 20) into the hydraulic cylinder (# 22). The check ball has pressure from the brake lines pushing back against it now (shown in ORANGE) and seats inside the piston allowing no brake fluid to pass by it back into the master cylinder. Therefore, the piston pushes more brake fluid forward in the lines and braking power increases.
The whole system uses brake pressure to overpower the springs and engage / disengage the control body valves. The reason this system works the way it does is that the vacuum created by the engine is able to travel throughout the Hydrovac unit (shown in RED). Therefore with vacuum in front of and behind the power piston, there is equal pressure on both sides. So until the valves close off that circulation and opens the air intake, the power cylinder piston won't move. Closing one valve stops that circulation throughout the unit. Opening the intake allows the cylinder to pull air from behind so the vacuum can pull the power cylinder piston forward.
Yes it does but I think these are the correct components to be mounted underneath
So would it have normally mounted behing the master cylinder? I doubt I will move it, but I do plan to go through and redo all the brake lines this winter (it is a mess from whoever did the hard lines!).
So would it have normally mounted behing the master cylinder? I doubt I will move it, but I do plan to go through and redo all the brake lines this winter (it is a mess from whoever did the hard lines!).
On the f100-f350 they were mounted outside the frame rail. I’ve only seen them on 56s. On f500 and larger they are mounted inside the frame rail behind the master cyl. Never seen one on a f100 53-55 so I can’t speak for them. I have had them on 53-55 f500 and larger and they are the same as the 56 larger trucks
07-30-2019, 07:13 PM
