That Ain't Gonna Work.

Dual master cylinder conversion leaves little room for brake arm...
I guess the old master cylinder frame boxing has to go?
20221124_170501 by Joe with a jeep, on Flickr

 

Ouch.

 

Could it work to bend the brake arm?

 

Hopefully I can get better pictures this weekend but here is the under side.
I'll definitely need to pull the old bracket off.
I'll have to double check the driveline position and refresh the mount situation. As it is the master cylinder is a motor mount. I'll be lucky to get 1/2" between them

20221124_170537 by Joe with a jeep, on Flickr

 

I pulled out all the ross steering, and driver side exhaust. I ground, drilled, and applied the BFH to the rivets holding on the clutch pivot. The bracket is loosely bolted in the rivet holes. The brake lines will definitely need 90 degree fittings if I ever want to work on the clutch or engine. I planned on drilling and taping the master cylinder for remote fill lines but those will need to be front and rear instead of on the side like focker's.
The top bolt holes will definitely be a pain. I'll have to drill a 1" hole through the floor and put covers or hole plugs on them after I drill the 3/8" holes into the frame.

I also need to add in the adjustable proportioning valve and mechanical stop light switch.

 

A swinging pedal conversion from an intermediate a possibility? Just asking.

 

Not really something I want to do. I have the stock heater workin great with a 15A motor, cable operated flow valve, and recirculating baffle.
My clutch is also set up really nicely, I have an 11.5" clutch but it has minimal pedal force at the bottom making stop and go trails a breeze.

 

Let me know if you need any measurements or photos. I have three Jeeps with the factory dual master cylinder.

 

I think I need the open distance between the frame and bellhousing. If I get a minute I'll be able to search for pictures from other threads but I don't recall anyone making a point to remove the old box section the single bore bolts to.

 

Hey Joe, When you add your proportioning valve and mechanical stop light switch , I mounted this further back on the frame . All in one & you can get an adjustable one, If you feel the need . Just try'n to help .

 

IIRC the factory dual master cylinder is actually tucked into the frame rail a little bit.

 

Here's a some pictures from my archives. I'll probably have time to take some measureents later today.

The dual master cylinder does tuck inside the frame a little bit. The side of the reservoir is basically touching the top frame. The cap sits above the rail and overhangs the frame a little bit:


Also note the brake pedal arm has some S bends in it to clear the V6 bellhousing and the master cylinder. As it goes through it's travel it only clears the two by a 1/4" or so. It's a tight space. You can sort of see the beds on the brake arm in this picture (brake arm is the rear one):

 

I got a wilwood adjustable proportioning valve last Christmas that will go in. I'm thinking of putting it on the inside of the frame just in front of my under seat fuel tank. I'll 3d print a handle extension to reach it with an access cover.
Dial down for topless snow plowing or full pressure for the hard top without plow.

Yeah I wasn't looking forward to bending the lever. I haven't decided on that one to cut and weld or heat and bend (i'ld be buying a small Mapp/O2 torch). I could also go crazy and make an arm from scratch.

I have a few ideas for mounting the switch. Eventually it will trigger the brake lights, center high mount stop light, and a trailer brake controller. The popup I borrow has brakes.

 

Fwiw this all started with a case of death wobble and removal of damaged steering components that contributed to it. Then I decided it's time to do this with the parts I've collected.

 

I cold bent the one on my '69 a little bit by clamping it in a vice and putting a pipe over it. They aren't that hard to bend.

Yay for scope creep!

 

Get acetyene/02, then you can use a cutting torch too. Every boy needs one.

 

Progress, before grinder was applied. I don't think I'll need to mess with the arm. The 4.3 block is gonna accommodate the right hand bend.

I fn hate youtube shorts, they don't link the same.
https://youtube.com/shorts/3hzUZ13QEI4?feature=share

 

Here is a picture of where the arm passes the block, I've basically removed the rib and corner of the block. Tomorrow the bump on the bottom hole of the bell housing will dissappear. I took the single master cylinder plate off the frame which bumped out about 1/4" away from the frame then I ground off another 1/4". Hopefully I can box it back in with 12ga and keep from compromising the frame there just behind the spring hanger. The block is getting ground smooth with the rib between the bank and bellhousing removed. I'll likely need to move the transmission over 1/4" for more clearance. I'll use 90 degree fittings for the master cylinder to avoid brake line damage with any future engine and transmission work.

20221126_191442 by Joe with a jeep, on Flickr
20221126_191629 by Joe with a jeep, on Flickr

 

@Fireball
Just to triple check... do the lines on your master cylinders go back to front or front to front?

Tech index reads they criss-cross,
http://www.earlycj5.com/xf_cj5/index.php?threads/128417/

 

I went out the shop to double check. On all three Jeeps (68, 69, 71) the rear reservoir drives the rear brakes and the front reservoir the front brakes.