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I've searched and searched called Wilwood blead and blead and blead. Setup is Wilwood dual MC with U.S. Brake MC's. All aeroquip fittings on SS braided line. ~19' of braided line makeup all the brake lines. I have the 7:1 ratio pedal and I cannot get braking power. On my first go around I blead and blead and blead and could not get much braking power and the pedal was very mushy, not hard at all. After talking to wilwood I got a couple plugs, pluged the MC's and could push the pedal all the way through. Wilwood said that means the MC's are junk, a pedal should only move a short distance and be very hard. So I ordered 2 rebuild kits for the MC's. Checked the bores of both MC's, both appeared to be fine no knicks or gouges ver smooth. I rebuilt the MC's and same problem. I can lockup the rears but the fronts do hardly anuthing. Brakes are new (remans) chevy one ton calipers, rear are chevy 1/2 ton. MC's are 3/4 7/8. I cannot get the pedal to harden up. Even are beading over a gallon of fluid through both MC's and making every adjust possible on the balance bar. Pumping does nothing pedal gets no better. I have blead them everyway I have heard to do it, by pumping pedal, with a mighty vac, taking calipers off hanging bleader toward the ground and cracking bleader screw and leave overnight to let all the air leak out. Maybe the US Brake MC's are just junk althogether and I should get new Wilwood's? I know for a fact there are no leaks in the system. Any help would be very much appreciated.
 

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are u usiing dot 5 fluid or dot 3. i was told to run the dot 5 silicon oil. dont know if it matters or not. mine are kinda mushy after several attemps to bled out. one mc to disc all the way around. last year i had to pinch off one of my rear hardlines and the system tightened up. i thaught there was some stuck air. i be watching your post for some advice as well. maybe we don have big enough mc, mines one one inch mc willwoodmcs and pedals
 

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are u usiing dot 5 fluid or dot 3. i was told to run the dot 5 silicon oil. dont know if it matters or not. mine are kinda mushy after several attemps to bled out. one mc to disc all the way around. last year i had to pinch off one of my rear hardlines and the system tightened up. i thaught there was some stuck air. i be watching your post for some advice as well. maybe we don have big enough mc, mines one one inch mc willwoodmcs and pedals
The silicone based brake fluids only exist for one reason. That is to protect the paint on old cars in the event it accidentaly gets spilled on it.

It's also not compatible with any other brake fluid and bad things happen if you need some on the trail and have to add some other kind.

Besides all that, it's non water miscible, has higher compressibility, and any water that enters the system will migrate to the lowest point and corrode that area, and or turn into a steam pocket when subjected to heat.
 

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I don't think you will ever get decent pedal with this much flex line.
Come stand on the pedal in my Amigo and tell me that... I have nothing but flex, and a rock-hard pedal on power brakes, even before I start the motor and enable manifold vacuum to assist.

7:1 on the pedal ratio is a good start... but how much fluid are you moving at the MC vs. at the calipers? Work the math out with your caliper piston diameters (times two) vs. the MC piston diameter, in terms of displace volume.

If you have a mushy pedal, IMHO, you have a bleed problem. If you have a firm pedal but bad brakes, that's leverage issues.

To bleed, FIRST bench bleed the MC into itself -- one of the benefits of that much flexible line is that you can use the actual flex lines to bench-bleed. Invest in some male plugs to plug off the end of your lines, and you can test pedal feel with no calipers attached, to make damn sure that you have bubbles out of the MC, which is IMHO the most common source of pedal-mush regardless of what kind of lines you run... though your user name seems to conflict your line choice. :flipoff2:

After talking to wilwood I got a couple plugs, pluged the MC's and could push the pedal all the way through. Wilwood said that means the MC's are junk, a pedal should only move a short distance and be very hard. So I ordered 2 rebuild kits for the MC's. Checked the bores of both MC's, both appeared to be fine no knicks or gouges ver smooth. I rebuilt the MC's and same problem.
Did you test again with the plugs? Pedal should be rock-solid with plugs.

....taking calipers off hanging bleader toward the ground and cracking bleader screw and leave overnight to let all the air leak out.
Bleeder DOWN would bleed out juice and leave air. Bleeder UP with an arch of line down below brake fluid in a can would prevent reflux of air... or you could do it easy with Speed Bleeders (I just did on my rig, and in less than 30 minutes, I'd flushed all old fluid from the system with new fluid <I swap colors semi-annually>).

Randii
 

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a buddy of mine with a light buggy is running the same willwood dual MC setup. he's got a 5.3 vortec and a 4l60e trans and using hardline throughout most of the rig, and still running drum brakes in the rear needless to say i think his brakes are dangerous cause of how spongy and unresponsive they are, they suck. now for him he doesnt even have room to do an e350 setup but if you (hardline04) have enough room for a e350 booster and MC then run it man! :eek: you will be shocked how awesome your brakes will be, i swear to it! the brakes on my buggy are better then the brakes on my old 02 acura rsx. this is my suggestion, now if you dont have enough room for that setup then :confused: idk i just know, what i got works and works awesome. if thats what you want yours to do then get what i got :smokin: sell your dual MC setup on ebay or something.
 

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OK, it's on the list Randii!

Let's see. trip to Cali:

- Disneyland
- Hollywood
- Wheel the Rubicon
- Press on Randii's Amigo brake pedal

:grinpimp:

Troubleshooting brakes - no quick answer. You gottta break it down, step by step, and be accurate in your problem description "no braking power" means didlly. Is the pedal soft, excessive travel, both, hard, just can't lock up, etc. You also have to invest in some equipment - plugs, pressure gauge, etc. if it's really stubborn. Isolate front to rear and side to side etc. to narrow down the problem.

I agree that MC bleeding is key. Often a bad (new/rebuilt MC) can be a problem, or maybe an imperfect home rebuild. Lot of times there's a small leak path somewhere too that lets just a bit of air in, frustrating even the most dilligent bleeders. It's a bit like an EFI motor - you can invest serious time and effort in troubleshhoting it or you can throw parts at it.
 

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Dumb question, but what size line are you running? I had a similar issue, was running 4an line and swapped to 3an and the problem went away.
 

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I've heard of pretty high failure rates with anything but NEW MC's. If you rebuilt it yourself though, that should be a little more reliable.

Step 1 is to ensure you have rock solid pedal with the MC ports plugged. If this isn't happening, the MCs are you problem. Let us know where you stand on that.

Paul
 

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Dumb question, but what size line are you running? I had a similar issue, was running 4an line and swapped to 3an and the problem went away.
Your line swap didn't fix the issue. You may have finally figured out how to bleed brakes or something during the swap, but the line size change wasn't what solved the problem.
 

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Come stand on the pedal in my Amigo and tell me that... I have nothing but flex, and a rock-hard pedal on power brakes, even before I start the motor and enable manifold vacuum to assist.
In the interest of not confusing anyone, the easiest time to get a rock hard pedal is when the motor is off and there's no vacuum assisting pedal applications.

The hardest time to get a solid pedal is when it's being boosted.
 

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Your line swap didn't fix the issue. You may have finally figured out how to bleed brakes or something during the swap, but the line size change wasn't what solved the problem.
True dat. Don;t think of brake hydraulics like steering or tranny where fluid is pumped and flows to do work. Think of it like really flexible solid linkage. Within reason - hose/line ID isn;t going to make any difference.

Or like I mentioned, you had a small leak you didn't know about, and inadvertantly fixed it with the swap.
 

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*chuckle* Lemmeknow when you get to Rubicon -- that's two hours a way and I don't need much temptation to make that trip... but as I recall you had some Croation brandy that sounded interesting... :homer:

I was knocking back some Nocino during my last point, and MrBlaine nailed me on the reversion... the pedal is hard before and after, but he's damn right that it is easier to have a stiff pedal without assist than with, since the vac-assist reduces effort.

So to review, I have s hard pedal and I drink too much. :p

Randii
 

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Discussion Starter #16
Thanks for all the help so far, I'll try to clear some things up. Pedal has excessive travel and is very soft. Brakes will not hold buggy on even a slight incline and have no chance when in low range (I have a CR of 94 (forumal used factored in torque converter with 1.75)). Line size is -4AN. MC's have been benched blead both times extensively. The remand pieces I was refering to are the calipers not the MCs. The MC's are new U.S. Brake 3/4" and 7/8". No, I have yet to replug the MCs after the rebuilds, that should have been the first thing I did :shaking:. I'll do that later this week and if I push through again I'll order Wilwood MCs and chunk the US Brake ones.
 

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well, my point was if you've rebuilt the MC's, they're essentially remans at this point.

Going back and looking over your op, i dont see you mention it....do you have a proportioning valve and residual pressure valves installed?
 

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How much does pumping the pedal up help? Your masters might not be big enough leading to a lot of travel, but the spongy feel would lead me to believe there is still air in the system. I know, it will make you go nutty trying to bleed it. You know there is still air in the system, but you can't get it out. It's a lot like doing a Ford clutch slave. The trick very often is to back-bleed the system with a pressure bleeder. At least if you did that you would KNOW once and for all that air isn't a factor.

Some people asked before, but I didn't see you answer. What fluid are you using?
 

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Just a thought...

The right hand calipers are on the right side, and the left hand calipers are on the left side? :homer:

I had a brake tech that put them on the opposite sides and drove him nuts for the entire day. But because he was "the man" and had many ASE certifications, I didn't want to look for the obvious. After he left, I went to take a look and thought :homer: :shaking:
20 minutes later, I had the truck finished:grinpimp:
 

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are u usiing dot 5 fluid or dot 3. i was told to run the dot 5 silicon oil. dont know if it matters or not. mine are kinda mushy after several attemps to bled out. one mc to disc all the way around. last year i had to pinch off one of my rear hardlines and the system tightened up. i thaught there was some stuck air. i be watching your post for some advice as well. maybe we don have big enough mc, mines one one inch mc willwoodmcs and pedals
You neet to read your instructions better, They say to NOT use DOT 5 silicone brake fluid.

If you have less then three people total at the time of bleeding the system you will not get them right.
 
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