Frankenstein Street Queen (a.k.a. SpeedBump)

Got the braided prop lines installed. Bled. Test fail. Bled again. Test fail again. Bled a third time and still no brakes. On a hunch took the master back off and remeasured my piston rod. Was off by a good 3/8 inch. Fixed that with a longer screw and got brakes!!

So to confirm- the e350 did NOT change my brake situation. It is better and it did shorten my braking distance from 60mph but I still can not lock up brakes. The next culprit is these flex brake lines. Gunna run the nicop along axles and frame. Need to find some good methods to safely and securely mount the hard lines to the axle housing.

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What I'll do for brake line tabs is like they did back in the 90s on back, use a strip of metal about 1/2" wide, 2" long, tack one end to the axle and curl it round the brake line. With just a good tack, it won't go anywhere. Always make sure the line is on top of the axle tube as much as possible just to keep it from getting crushed.
 
If your pedal is firm, but the brakes arent locking up, I would bet that lines/hoses arent your issue. It is likely that you arent able to extert enough force to lockup the brakes (ie you cant generate enough pressure).

What calipers and rotors are you running again? What is the bore on your master? What was the bore on your old master?
 
Anyone got a 27 spline input gear for a Chevy new process case used on 4L transmissions?

Needing to do some r&d

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If your pedal is firm, but the brakes arent locking up, I would bet that lines/hoses arent your issue. It is likely that you arent able to extert enough force to lockup the brakes (ie you cant generate enough pressure).

What calipers and rotors are you running again? What is the bore on your master? What was the bore on your old master?


Then maybe its not "firm". Its not as "firm" as the corolla or our other vehicles (newer).

I am using 3/4 chevy rotors and calipers. I had a stock CJ master on there and "emergency braking" wasnt a possiblility, neither was lockup. Now with the e350 my braking distance is definitley smaller. I would feel better in emergency situation but i still can not lock up.

When the engine is off the firmness of the pedal feels like a stock newer vehicle, but slightly harder. with the engine on (booster), my initial reaction everytime i use the brakes is "man, this travels Too easy...".

At first I looked into the travel distance of the pedal. I thought maybe it just wasnt enough? So i lengthened it about 3/8 to 7/16 an inch - no change. however i did do that when i had an unknown piston rod length issue. regardless moving it that much put the pedal so high you have to lift your foot to use it, rather than pivoting your foot on your heel. took a dangerous moment or two to get used to that, but one stupid asheville driver almost had their rearend caved in because doing it that way (lift the foot all the way, like for clutch pedal) resulted in my foot getting caught under the pedal. barely stopped in time for that one. lol.

Anywho, hoping to leave the pedal where its at for safety reasons. I can now confirm that the piston rod from the booster is about 1/8 inch from the seat of the piston. For max throw. My brakes and master have been bled (to the best of my ability without a vacuum bleeder). Seeing as how everyone and their mother does these 3/4 ton master and caliper swaps, i have a hard time believing they could be the issue? but im certainly not the expert.

My gut says its either these lines (non braided so they should have some amount of expanding flex?), or its the booster. I dont know enough about booster technology. The way I understand it, its just a vac diaphram to help give more force on the brake pedal to rod to m/c piston. However if that rod isnt going all the way through, but relies on one diaphragm with pedal and rod to push on another diaphragm with rod to piston, then perhaps there is something defective that is not allowing the rod to piston to travel the same distance as the rod from the pedal, resulting in proper throw with engine off, but defective throw with engine on. But that cant be it i think because to my knowledge the rod goes all the way through? and if that was true then when i had the big issue with the improper piston end rod length i would have wrecked many times over?

The only thing i know to do is lines (which everyone says to do anyways for longevity and safety reasons). @XJsavage had the simple idea for the old school tabs, but also curious about these barnes tabs that @YJJPWrangler pointed out.

Thanks @paradisePWoffrd for the help! Any thoughts after this diahrea of the keyboard? lol.
 
Need to take a pressure reading at the calipers and see what you are getting. That booster is pretty small, you could gain a good bit of pressure at the calipers with a larger booster. If you have good pressure at the calipers (900psi minimum as a general rule for discs) then you can look into some better friction materials. Start with a pressure test and go from there.
 
Need to take a pressure reading at the calipers and see what you are getting. That booster is pretty small, you could gain a good bit of pressure at the calipers with a larger booster. If you have good pressure at the calipers (900psi minimum as a general rule for discs) then you can look into some better friction materials. Start with a pressure test and go from there.

its an aftermarket dual diaphragm booster. 8" i believe and a stock is 9 or 10?

Correct me if im wrong, but the booster should have no bearing on the pressure generated. that should all be the m/c and how far the piston is moved? the sole purpose of the booster being a vac line on one side of the diaphragm to make it "easier" to push the brake pedal? So, regardless of booster if you can make your pedal go all the way to the firewall, then that means youre not having a power"assist" issue, right? the way i envision it, is if a booster was too small or under performing your leg would lack the strength to push the petal far enough to get to the clamping pressure needed?

a failed or under performing booster would equate to the feeling/results of manual brakes. right?
 
Booster will affect pressure as it will essentially help you push the pedal farther to produce more pressure. If you can push your pedal to the floor then something is not setup correctly. You may have a combination of issues. Air in the lines still, improper sized master, ballooning lines, etc. It sounds like you still have air in the system or not enough fluid volume to fill the calipers. It doesn't take much air at all to make a shit pedal with the engine running (help of booster).

Yes, a failed booster will feel like the brakes when the vehicle isn't running or no vacuum line hooked up.
 
Booster will affect pressure as it will essentially help you push the pedal farther to produce more pressure. If you can push your pedal to the floor then something is not setup correctly. You may have a combination of issues. Air in the lines still, improper sized master, ballooning lines, etc. It sounds like you still have air in the system or not enough fluid volume to fill the calipers. It doesn't take much air at all to make a shit pedal with the engine running (help of booster).

Yes, a failed booster will feel like the brakes when the vehicle isn't running or no vacuum line hooked up.

awesome. thats how i thought of it in my head. thanks for the input man. next week ill toss a brake vacuum on the system and see what that does. i hope its something as simple as that. i plan on doing the hard lines anyways so maybe that will help in some way as well. We shall see!
 
From running the numbers, assuming the lines are fine, I would say that you likely either need a bigger booster or smaller bore master with residuals. You went from a 1" bore master to a 1.125" bore. That would have solved the problem if you werent filling the calipers, but had plenty of pressure. You are now generating less pressure than before, but moving more fluid.

What proportioning valve is that? does it have any residual or limits in it?

As said, the pedal should be hard with no vacuum. But soften as the booster sees vacuum. If it doesn't, the booster is bad. The booster only allows you to apply more push force on the master, so that that you create enough line pressure combined with enough volume. Have you tried to fast pump the pedal? Does it pump up any?

The stiffness of the pedal comes from the pressure feeding back into the system. Pressure is resistance to flow. If you do not have enough volume to fill the calipers, the pads will not move, and therefore create a "stop". Same as if the hoses/lines swell, they dont stop the fluid flow, but just give it a bigger path. So first, you have to fill the caliper, and then apply force to the pad, through the hydraulics, to clamp the rotor. A residual valve retains fluid in the caliper, which allows you to run a smaller master, which will net you higher pressures with less pedal effort. This is how must get by with manual brakes. With power systems you can run a larger master to move more fluid and the booster gives you extra pedal force it requires to move the master piston.
 
@paradisePWoffrd it would appear then that i am sending more the right volume, but that i am not building the right pressure (line expansion) - from the way youre describing everything then.
 
If you think your lines are an issue, I would fix them first. Then you likely should check vacuum at the booster and line pressure at the calipers. That should tell you where to go next.

The fact that switching from a YJ master to the E350 master didnt change much, tells me that something else could be going on. There is ~500psi difference between those 2 masters, given the same pedal effort.
 
If you think your lines are an issue, I would fix them first. Then you likely should check vacuum at the booster and line pressure at the calipers. That should tell you where to go next.

The fact that switching from a YJ master to the E350 master didnt change much, tells me that something else could be going on. There is ~500psi difference between those 2 masters, given the same pedal effort.


could there be an issue with the prop valve?
 
could there be an issue with the prop valve?

It depends on what it was designed to do. It could be a simple splitter, but could also have reducers or residual valves built in.
 
Made me a new shift and wiper lever. From a push rod and lifter from the 258 the YJ came with. Pretty cool I think.

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fixed a mismeaurement issue on the push rod for the brake mc piston. i can stop just fine and make the nose dive under braking. still cant lockup but it has been proposed this is more of an issue of the size tires, etc. Ill stow the brake line changeup for a little while and focus on a few other things. But i do have the nicop ready to go for it.
 
That's the same bulkhead I purchased. I didn't feel that there was enough sealing surface on the -10AN thread side, there is physically no male 37° flare at all to seal against, I cut them off and welded -AN fitting on there. Let us know how that works out.

The -10an flare fit perfect on the bulkhead. Ill let you know if there are any leaks! Ill be putting the clamps on this weekend and giving it a test run
 
Well the -10an bulkhead did end up leaking. What I did as a temp fix was use some gunk to seal the threads and the seat. I’ll have to figure some else better out in the soon future. Maybe this will stay leak free through the winter?

I had hoped to find a barbed bulkhead fittings but could t find them when I did all my searching. Now that I have these and fittings on the one side what I will do is look for -10an to -10an bulkhead fittings and just get two more an fittings for the engine side.

I don’t like using hose clamps because they look super nice. Realized tho at the last minute I didn’t factor the hose reduction for this bulkhead so had to make do with what I had on hand.

Well it’s all hooked up and holding fluid. I’ll do a test run tomorrow in the SNOW!

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Ya know, I just drilled a 1" hole in my firewall and wrapped the 5/8 hose with a small section of 3/4 hose.
Not that you have ever been know to overcomplicate things buddy...:D

We're all set for Monday to do the 8.8 axle. Holler at me this weekend and we'll set a time.
 
Ya know, I just drilled a 1" hole in my firewall and wrapped the 5/8 hose with a small section of 3/4 hose.
Not that you have ever been know to overcomplicate things buddy...:D

We're all set for Monday to do the 8.8 axle. Holler at me this weekend and we'll set a time.

10-4

Yeah no kidding. Funny thing. I had the hoses routed like that in the start straight through the firewall. If it leaks still I will def be doing that because who likes spending money lol
 
Finished the heater hoses for the mojave heater. Man that thing is a hot box. When the water pump got up to pressure the bulkhead fittings leaked as you predicted @mcutler lol

So just ran hoses straight through the firewall for now as @Jody Treadway suggested.

Then took it for some play in the snow

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