Straight pedal, move the darned post and 6* to redemtion

[Lumpy Grits]

Trailers(registered as such)over 1500lb 'gross' weight require working brakes on at least 1 axle. There are some exemptions for farm equipment etc. that vary from state to state.
There's no 'working brake' requirements for towed motor vehicles. BTW-It's against Federal law to alter you vehicles OEM brake system.
I do know of some folks that have used those 'helper' brake deals. Runs about 50/50 on liking them.
LG

 

[Hedgehog]

Back to the original posts. So, now I'm breaking the law.......

 

[Lumpy Grits]

Back to the original posts. So, now I'm breaking the law.......

Na-You 'fixed' yours-
LG

 

[Hedgehog]

Yeah - it seems like most days I find myself in one fix or another

 

[Lumpy Grits]

Better than being in the 're-cycle bin'........
LG

 

[Hedgehog]

I hate to admit this, but now I'm reversing some of what I did to make the brakes work as they were.

Lengthening the pedal was definitely the thing to do, in one form or another I'll be keeping that.

As received in "the Whole Shebang" power brake upgrade kit thee booster was a long powerful double diaphragm booster. To somewhat tame the booster I took the great advice given here and moved the brake rode pivot pin on the pedal arm from it's 5:1 ratio to a 4:1 ratio. This proved to be pretty much on the money as far as improving brake feel. No more "face smashed in windshield" moments for me.

While learning to live with my new brakes I noticed that some times there was NO boost with a second pedal like you might find coming to a stop sign. First pedal had a nice stopping feel, second pedal was hard as a rock, lose of vacuum assist. The CJ had plenty of vacuum 18 @ idle, ~20 while driving, +22 on deceleration. The booster proved to be bad. So, with under hood space being a problem I replaced the long double diaphragm booster with a shorter single diaphragm booster. The brakes are still good, but the pedal is hard. So now I'm going to pull the pedal ... again ... and replace it with a pedal with the pin back in a stock position. This should/will restore the over all brake feel. Yes I know, round and round we go, but this was a good experience and it might serve to solve other peoples brake conversion problems.

 

[Posi]

I took the great advice given here and moved the brake rode pivot pin on the pedal arm from it's 5:1 ratio to a 4:1 ratio.

Moving the pushrod down 1", was there a need to move the booster to center the pushrod?

 

[Hedgehog]

There would if you had an arrangement like a stock manual braking system. That system pushed directly into the MC. A system that pushes directly into the MC could create a problem with the MC as well. A power brake system in a CJ has a lever arm arrangement between the booster and the firewall. The piston rod from the booster goes directly to a lever and that angle arrangement never changes. A second adjustable length rod goes from the lever to the pivot pin on the pedal. Perfect alignment isn't necessary. But, the push rod in my system has an offset eye for the pin to index. The off set eye can e arranged either up or down. I arranged mine to have the straightest push angle possible.

 

[jammer1]

The yj brake upgrade requires the yj with a dual diagram booster. Going to a single booster (same diameter as stock) would give you brakes about equivalent to the stock power setup. If you're less than 33" should be fine, if running 33 to 35" may not stop as easy as you would like. Over 35" may have a problem. I didn't catch what you had. Good write up. Thanks for the real life feel with the mods. Usually we don't get the feed back after running a little while. Thanks.

 

[Hedgehog]

The double diaphragm booster in my opinion is to powerful for the 31" tires I have. With the pedal modifications that were done made braking far more manageable. But 4 wheel skids on pavement was easily accomplished. Serious amounts of control were needed. I can see where after a couple hours of relatively fine pedal control having serious muscle cramps in the lower legs. The single diaphragm booster requires more pressure, but in some ways is easier to control. Moving the pin back will do the opposite of what moving it did. Changing the ratio from the 4:1 back to the factory 5:1 should require less pedal pressure.

 

[Hedgehog]

Okay - Done! Moved the pivot back to the original 5:1 position. At this point I can see no reason to touch the brakes again. Plenty of brake, decent feel, all 4 wheels seem to be braking evenly and at the right time.

 

[jammer1]

Glad you have it so it brakes good and also has a safe feel. Wasn't sure of the size tires you have, 31" is fairly close to stock so you are correct, I can picture you going through the windshield on a panic stop. With 33's I have that feeling but I had manual brakes on before the power setup and was standing on the brakes to do a hard stop. Seriously thinking of trying to move the pin on the brake petal to see if I could get it a little less touchy. Again a good write up with first hand experience on the whole process. Thanks.

 

[Lumpy Grits]

Good news HH.
LG

 

[Hedgehog]

jammer1 - Thank you. Too frequently my threads like this run on and on, but one (well, two) of my reasons for being here is to learn and to help others do something similar. Yep, the good, bad and the ugly. Projects rarely go as expected, that doesn't mean its a failed effort.