Underdash Master Cyl.?

[bbchopped]

Im trying to get back to work on my '45 dodge truck and I am needing to make a decision on my master cyl. and booster. I have 4 wheel disc brakes so I guess I have to run a booster. The problem is I built a custom frame, and everything has worked out perfect so far, but when I built it I didnt even think about using a frame mounted mc. So now, when I held on up to the frame to look at the placement, my frame is just narrow enough the pedal will be to close to the trans to put a gas pedal in. I dont want to mount one on the outside of the firewall, and really dont have an extra $425 or more, for a 90deg underdash boosted mc and pedal assembly. I wish I could find some way to build or adapt my own underdash setup, but I would need to see one in person or have really good photos to do it. Any ideas? Im ready to get this thing done before spring!

 

[Crossfire]

master

You got any pictures of your setup?

 

[Gastrick]

Under the dash of my brother's 55 Chevy. It's hard to get a good photograph in there. Donrod's son has one in his RPU that's set up nicely. I'm sure Don will chime in if he sees this.

 

[LOWANDRATY]

where to mount it

You could mount it back under the bed and run a frame mounted pedal, with a long rod to the booster.

 

[bbchopped]

Heres a few pics I ran out and took if it helps. Gastrick did he buy it as a unit or build the pedal assembly?

 

[bbchopped]

I have never thought of that but that might definately be an option. Do you know of any pics of any done like that?

 

[Gastrick]

I have 4 wheel disc brakes so I guess I have to run a booster.

This isn't necessarily true. I have a car with 4 wheel disk brakes.....with no booster. The car stops very nicely without effort. I mounted the m/c to the firewall and used a hanging pedal in that car as there was very little chassis room. Are you opposed to mounting the m/c to the firewall or are you trying to keep that area clean?

 

[Gastrick]

Gastrick did he buy it as a unit or build the pedal assembly?

It's a Kugel unit.

 

[TiredIronGRB]

This isn't necessarily true. I have a car with 4 wheel disk brakes.....with no booster. The car stops very nicely without effort.

True...the last two cars I built had four wheel disc brakes with no booster.

 

[bbchopped]

This is my first ground up build and I have had two different old street rodders tell me I had to run a booster with 4 wheel disc brakes. I just took there word for it. Do I still need residual valves without a booster. If so what size did you use? Also as far as the firewall mount I just dont want anything outside on the firewall for a clean look.

 

[Gastrick]

You need 2lb residule pressure valves for disk brakes, 10 lb. for drums if your calipers are mounted higher than your m/c. I am telling you with utmost certainty that you don't need power brakes just because you have 4 wheel disks.

 

[CB_Chief]

booster with disc brakes

If you have to have a booster with 4 wheel disc then GM should have been in trouble years ago. My '67 Corvette Roadster came factory without a booster and it had 4 wheel discs. And I can't begin to count the number of late 60s up to about 1970 'vettes that came through our body shop factory configured with non-power assisted 4 wheel discs. Quit listening to people who don't know what they are talking about.

 

[donsrods]

Bill is right, my Son Dan is using the same Kugel Komponents 90 degree pedal assembly as his Brother Rod, and it is a really slick unit. Not cheap at $425.00, but it is almost a bolt in. (some fabrication is needed because every car is different) I wanted the same unit for the rpu I am building and considered measuring Dans and making my own to save some money. But after looking at it I just went ahead and ordered one from Kugel.

Bill is also right about NOT needing a booster for 4 wheel discs. Hot rods are not Lexus' and we like a little pedal feel and stuff like that in our cars. You also will NOT need a residual valve because the unit under the dash is higher than the wheel cylinders or calipers so there is no chance of bleed back.

Here is the unit Dan put in his rpu.

When it is installed you don't even know it is there.

Don

 

[donsrods]

Someone asked on another forum how you fill the master cylinder as it is up under the dash. Dan added a 32 Ford cowl vent to his 30 rpu cowl top so all he has to do is reach down through it and check the fluid. But checking the fluid is something you rarely have to do, if ever.

Don

First he marked the area to be cut out and drilled holes in each corner.

Then he trimmed the new cowl vent from Brookville Roadsters to fit the opening.

And welded it in place.

And when all done it looks like this.

 

[Cutls67]

I am also interested in doing this set-up on my 47 Power Wagon also. I think I can fab mine up by looking at your pics. I have one question though on how you guys ran your line out to your distribution block. Is that under the dash or is it out side the firewall?

Thanks Stephan

 

[bbchopped]

My truck already has a cowl vent opening like that so I wont have any problems. I will look at the price of a underdash unit without the booster I bet it will be much cheaper. Maybe you can see the cowl vent in these older pics.

 

[Tim...Ok]

Thats a really cool truck BB,especially like those headers..very nice

 

[donsrods]

Yep, it is cheaper with only a manual master cylinder.....$ 305.00. As for the lines, we just ran them inside the dash and out the floor under the kick panel on the passenger side so they were hidden.

Don

Here is the assembly you get for $ 305.00 It also comes with a bracket to mount your brake light switch into.

 

[bbchopped]

Thanks! Those pics are when I mocked up everything. I have since broke it down to weld and paint everything. I will try to get a few more pics on here soon. I havent search alot, but www.ecihotrodbrakes.com has the manual setup for $275 which isnt bad at all IMO.

 

[pacrat]

may or may not help

I'm not sure if its what ya need but, some vans have a 90 degree setup from the factory, i know my old 76 chevy motor home does, might be worth looking at.