billyblankss Posted July 28, 2020 Share Posted July 28, 2020 Sorry I know there have been posts on this before, and there's a good one in the write up. My 87 4wd 4.0 short bed - I can't seem to get the brakes where i would like them. I bled all four brakes and it seemed ok, maybe 75% stiffness i expected. I tried going through the factory bleeding procedure described in the posts here but it seemed to make it less "stiff". I have a view variables that may be contributing to the difficulty... 1. when i purchased the truck the original hardware for the rear proportioning valve was totally missing. It looks like it's still hooked up, although I can't definitively tell if it was "deleted" because I'm not sure what i would see... all hoses look "normal". I was able to move the valve arm up and down, and for the brake bleed procedure i opened the front caliper, raised the arm to like 11 oclock or 1 oclock depending on your perspective, and re-bled the rear... but the brake light never came on indicating it had "shuttled" open. 2. This may be the issue, but i had self bleeders installed in the rear. So while i can open the rear, it's not really "open", it's just open so when i push the brake it will pump the air out but not suck anything in. Is there a video anywhere of the shuttling / brake bleed procedure? Can't seem to find anything. Sorry for newb-ness but i guess i'm trying to hunt down where the source of my user error is. Link to comment Share on other sites More sharing options...
Pete M Posted July 28, 2020 Share Posted July 28, 2020 can you share a pic of what the rear prop valve and hoses look like? Link to comment Share on other sites More sharing options...
billyblankss Posted July 29, 2020 Author Share Posted July 29, 2020 Took some pictures. He's the view from the tailgate. I bought new hardware for the prop valve but haven't installed yet, zip tie is holding it at that angle Link to comment Share on other sites More sharing options...
billyblankss Posted July 29, 2020 Author Share Posted July 29, 2020 Also don't know if this is relevant but I'm not sure how much resistance the arm is supposed to have, I could move it up or down very easily. Link to comment Share on other sites More sharing options...
Pete M Posted July 29, 2020 Share Posted July 29, 2020 all mine have moved quite easily. everything appears to be where it should be. I see the PO added in an extension soft line. I would probably use a bungee to hold that up and keep it from snagging anything. If the brake light doesn't come on, then I imagine that means the shuttle didn't move. and speaking of snagging, it looks like your lower shock mount found a rock. Link to comment Share on other sites More sharing options...
billyblankss Posted July 29, 2020 Author Share Posted July 29, 2020 nah that soft line was me - part of the rocky road outfitters 6 inch lift. I'll have to check out the spring perch... it's part of their spring over axle setup. I'll try to bleed again - and i'll zip up that line so it doesn't catch on anything. Thanks! Link to comment Share on other sites More sharing options...
Comanche man Don Posted August 1, 2020 Share Posted August 1, 2020 I am having this same issue right now. I can’t get the brakes to bleed properly and have tried all the advice I’ve gotten here and on the net. This has been a battle for a very long time. I have even considered getting rid of the truck over it but I really don’t want to do that. If you figure it out let us all know . It’ll be greatly appreciated. Link to comment Share on other sites More sharing options...
Pete M Posted August 1, 2020 Share Posted August 1, 2020 the bleeding procedures are in the link in my sig. these the steps you guys have been doing, yes? Link to comment Share on other sites More sharing options...
billyblankss Posted August 2, 2020 Author Share Posted August 2, 2020 Yes. I bleed all four brakes. Then I go and open the front caliper bleeder, move the proportion valve arm open the rear valve and push the brake to the floor with the key on. And immediately shoot break fluid all over my shop. I've tried also cracking the front bleeder slightly, opening the rear bleeder and then dripping fluid everywhere. The only thing I haven't tried is opening the front bleeder, keeping the rear bleeder closed and then stepping on the brake. After going thru a whole extra bottle of fluid, which I don't care is cheap and flushes system but is a huge mess.... I gave up and just bled them one more time. Man I know I'm either doing something dumb or missing something dumb so I'm disappointed in myself but it is what it is. Link to comment Share on other sites More sharing options...
Pete M Posted August 2, 2020 Share Posted August 2, 2020 I think you're supposed to leave the rear closed when you open up a front to move the internal bypass. you need to fake that eh fronts have failed so that the system opens up the bypass line. be sure to have a hose/bottle hooked up to the front open bleeder so you catch the fluid. Quote Open a front caliper bleed fitting and depress the brake pedal to the floor. This will shuttle the by-pass differential valve and allow fluid to flow through the by-pass line. The brake warning light on the instrument panel will illuminate when the ignition key is in the ON position. This signals the shuttling of the valve. Re-Bleed the rear brake cylinders with the front caliper bleed fitting open. After re-bleeding the rear brake cylinders the entire system must be bled again. Bleed the brake calipers and cylinders in the following sequence: 1st -- Right rear 2nd -- Left rear 3rd -- Right front 4th -- Left front Link to comment Share on other sites More sharing options...
Pete M Posted August 2, 2020 Share Posted August 2, 2020 having said all that, it is possible (though unlikely) that your front combo valve was poorly machined and the emergency bypass doesn't connect. Eagle found one like that. Link to comment Share on other sites More sharing options...
Eagle Posted August 2, 2020 Share Posted August 2, 2020 4 hours ago, Pete M said: having said all that, it is possible (though unlikely) that your front combo valve was poorly machined and the emergency bypass doesn't connect. Eagle found one like that. I sure did -- the one in the photo, in fact. The vertical bypass passage wasn't drilled all the way up to open into the horizontal bore that the brake warning light shuttle valve slides in -- right where I put the red circle that's labeled "Emergency Bypass Circuit." I doctored the photo so it shows how the thing is supposed to work. Link to comment Share on other sites More sharing options...
silvertwinkiehobo Posted August 4, 2020 Share Posted August 4, 2020 Oh, that's nice.... Not. Link to comment Share on other sites More sharing options...
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