New Brake Linkage - how to solve?

[Rigger]

Plodding along on my brakes project on my 1970 FJ40.

https://forum.ih8mud.com/40-55-series-tech/281587-riggers-disc-brake-conversion.html

The new booster/master is mounted to the firewall via the adapter bracket. This bracket spaces the booster off of the firewall, so there is now some space (about 3-1/2") to make up to connect the booster rod to the brake pedal. How have you done this?

I could get a 10M threaded rod and coupler

or

I could have one of those fork devices custom made in the correct length.

What do you suggest?

 

[cruiserbrett]

dont know that I would go threaded rod(depends on its quality) but a good hardened stud and a coupler would be fine. there is alot of leverage trying to compress that linkage and any weak point invites a bend. catastrophic results to follow. So make it strong.

 

[grant5127]

I didn't read your build thread but, looks like you have the wrong booster if your using the space to clear the reinforcement brace on the firewall..........

 

[Rigger]

dont know that I would go threaded rod(depends on its quality) but a good hardened stud and a coupler would be fine. there is alot of leverage trying to compress that linkage and any weak point invites a bend. catastrophic results to follow. So make it strong.

I agree; there is a fair amount of force on that push rod.

 

[Rigger]

I didn't read your build thread but, looks like you have the wrong booster if your using the space to clear the reinforcement brace on the firewall..........

I do not know how to select the booster, so I discussed my situation with Mark Algazy of Mark's Off Road. He selected the booster and master for me and sold them to me. Are you saying that the "right" booster would have a longer rod? How'd you set yours up?

 

[grant5127]

I dunno what you have there Rigger.....

I've only done this conversion 3 times but, the (supplied to me) booster, rod was long enough to reach the pedal after passing through the spacer and firewall..........
Thats the concept JTO and Warden used on the design.....

I've seen several '82 era minis that had the factory spacing between the booster and firewall so I grasp the idea.....

I have more info at my shop on this but will be Monday before I return, so if it will help I'll get the scoop on it.........

 

[fieldsken1]

you can extend the rod thats fine thats what i did. in fact i might have another piece made to fit

 

[grant5127]

Say Rigger.....

Your booster resemble the pics?

Long rod & Long ass studs protruding out the backside?.......(obvious needs snipped off a bit when used with the 40 spacer idea)............

 

[Rigger]

Thanks Grant; the rod on my booster is shorter than that one. I'll get into the garage Monday or Tuesday and measure it up.

This confirms what I thought earlier. I need an extender on that dude. I'll post up what I come up with over on my brakes thread.

Thanks for your help.

 

[Seth_O]

I used a grade 8 stud and a pair of couplers. Never had any problems with it, and it preserves the ability to fine-tune the length to get exactly the distance you need.

 

[Rigger]

Can anyone confirm the size of the stud? I'm pretty sure it is M10x1.5.

It looks like I will need one about 3" to 4" long (75mm to 100mm) and a long-barrel coupler.

I'll check at Fastenal on Monday.

Edit: The thread is M10x1.25.

 

[Rigger]

Here is another pic of my booster with the yoke. The rod needs to be about 3 to 4 inches longer.

 

[Rigger]

Here is my solution. Custom machined yoke. (I hope it fits!) I will test the fit this evening.

The pic shows the factory yoke and the longer custom yoke.

 

[cruiserbrett]

thats the way to do it right! Looks great!!!

 

[mtweller]

Nice, creative solution. Is that solid stock?

R

 

[Rigger]

Thanks, guys. I just hope I can get it to fit in there! Doing anything under the dash of a truck is difficult and painful!

The new yoke is made from solid bar stock; what they refer to as 1018 steel.

 

[Rigger]

Here is the new yoke, in place.

One problem is that it is not adjustable in place. If I need to shorten or lengthen it, I have to unbolt the booster from the firewall bracket, shift the whole thing forward until the yoke is clear of the brake pedal, and then turn it.

Not sure yet if this is going to be a problem.

 

[mcwinery]

Size thread

What is the thread size you tapped out for this? I am making one and could not find the correct thread size at ACE.

Here is my solution. Custom machined yoke. (I hope it fits!) I will test the fit this evening.

The pic shows the factory yoke and the longer custom yoke.