Mojave_Moze

So after about 7 month of being garaged, I Finally finish the instal of a brand new total chaos suspension only to realize, for some reason, I have no braking power at all.
Here's the deal: during the instal of the suspension, I had to replace both front brake lines with steel braided lines, I also rebuilt the calipers without breaking them in half, all I did was remove the old boots and pistons, cleaned everything out and replaced the boots and seals. But now, when th brakes are pumped up, only one side of each caliper will get pressure and press on the rotor, as if no fluid is getting to one side, so we then unbolted and split the caliper and found no clogs or anything.
I'm not sure if the calipers are the issue really because I've also:
1.)replaced the master cylinder ( yes I bench bled it thoroughly)
2.)checked for leaks and vacuum leaks and checked for bad lines and fittings
3.)bled each corner of the truck MANY times, cycling about 2 quarts through every corner
However, once the truck is started, the pedal goes right to the floor without resistance and the truck will not stop without using the e-brake.
The only thing I can reasonably think of is that there is air trapped in a line somewhere. But just can't seem to push it out without a power bleeder which is really hard to come by....
Is there anything I could be over looking? This issue is driving me crazy cause I've been waiting to have my rig back for months and now that the new suspension is done, I can't go play with it
It starts, idles, steers, and runs great, but it just won't stop! Any help would be great!

wyoming9

iTrader: (1)

I would guess someplace you either have a connection loose that sucks in air and leaks very little fluid . Could be a bad bleeder valve allowing air back in

It would be nice to know what year you are working on??

Just how are you bleeding your brakes?? is your helper paying attention??

Did you get air out of the lines when you first started??

Was the master cylinder a new one ?? is it the correct one??

Do the pistons move free in the bores ?? What kind of shape were the bores in where they nice and clean. Were they leaking that you decided to rebuild them.


Some place you are getting air back in the system

xxxtreme22r

You bleeding the LSPV? or just the 4 corners, recently I had this problem and it was air trapped in the long arse line going from the front brake to the rear LSPV.

Mojave_Moze

Wyoming: it's a 1987 4runner, the boots on the pistons were shot before I replaced them, when I took the pistons out, they were pretty dirty with a lil rust, but I cleaned out the bores and the pistons, and replaced seals, I even went as far as using an air hose to blow all the old fluid out of the calipers.

I looked at the lspv, and didn't see a bleeder valve, does that mean taking a line off and bleeding it that way??

xxxtreme22r

LSPV doesn't have a standard bleeder screw like the brakes. SO I am almost now certain this is what your problem is.





You see that bolt head I broke on mine? Yeah, that's supposed to be the bleeder and the nipple for it is right by that, like in this photo, it might have a plastic dust cap on it. Its just to the right of that bolt head. If you break the top of that bolt off, your gonna have to crack that line in order to bleed most of it. That's what I had to do. But your gonna need a helper to pump the brake and hold the pedal down while you tighten it back up, otherwise you'll suck air back up in the line. You have to do this the same way on all 4 corners if your not using a 1 man bleeder setup with a hose in a bottle half full of fluid.

Mojave_Moze

Alright, I'll look into that, I definitely have an odd looking rubber nun next to that bolt on mine so it will be getting bled too. However, I have literally been using a vacuum pump to bleed the brakes myself all day, and after several hours on one corner, theres still air in the lines somehow, not sure if the vacuum pump is causing the air bubbles, but I have yet to see solid streams or fluid come out of ANY corner. If we can't get the lspv bled and all the air out, I'll be taking this thing to a brake shop and have it put on one of those super duper power bleeder. Hopefully we can get the lines bled though, not sure how much more my knuckles can take though from slipping off a brake fluid covered wrench....and it's cold outside ;_;

SCToy

What order are you going in?
Because toyotas are a little weird and if you look at the brake lines the Driver rear is actually further away than the passenger rear, so it gets bled first.
Sounds like you've bled it more than enough, but just throwing that out there.

xxxtreme22r

If there is air in that LSPV line the front brakes won't get pressure. Most brake shops don't do those LSPV's for some reason, I don't know if they know it gets bled or not. I'd bleed that first then the DR, PR, PF DF. I Hate bleeding brakes by the way. lol.

Mojave_Moze

Just tried bleeding the LSPV, and there was (and still is...I quite after 10 tries) a LOT of air in that line, but once I get solid fluid out of that, I'll move in to the order you suggested Xtreme, Thanks! I'll post if anything else comes up by the end of the night. If not, then there will be trail pics of this Total Chaos rig on my build thread very soon!

xxxtreme22r

Yeah that line is a big B to bleed, it's a long arse line.

Mojave_Moze

Whats a better method when using a hand-actuated Vacuum pump? Pump it up then crack the line? or crack the line and just keep pumping?? Cause it seems like all Im getting are mass amounts of air bubbles. I'm still getting fluid out but not a steady stream, and the bleed line im using is pretty small so once its solid it should fill the line right?

xxxtreme22r

I sucked mine out using a homemade engine powered vacuum bleeder after holding the pedal to the floor with a 4x4.
Just watch that master cyl fluid level. Then I put the line most of the way on and had an assistant push the pedal down while I tightened the connection back up.

Mojave_Moze

O.o that device sounds amazing, I want one!

xxxtreme22r

Canning jar with two holes cut out of the top, two vacuum lines attached to it.

Mojave_Moze

:O I feel silly for not thinking of something so simple yet so amazing....oh my cramping hands ;_;

Well, time to find a Jar (or maybe in my case, a bucket) and call a buddy!

xxxtreme22r

Idea taken from this: http://www.wristtwisters.com/forums/...der-14600.html

Worked with what I had, but I had to step the line size up. Since this one was on a motorcylcle forum.

This one instead of using a vacuum source uses an Air compressor and the venturi effect.

But if you do it this way or my way, you have to watch that master cyl level, it's real easy to drain it. And you don't want to completely fill the jar and suck up brake fluid into the engine. Ask me how I know. lol.

Mojave_Moze

OK, so we built a similar bleeder and after even more hours of bleeding, still nothing. SO we went back to conventional bleeding. Only to discover, we had SOLID fluid coming from:
LSPV
Drivers Rear
Passenger Rear

BUT, barely a trickle from the front corners still. So after a few beers and some more poking and proding, I finally decided to give the calipers a looksy. Turns out my previous caliper rebuild was complete crap, I had no idea I was supposed to Hone, and NOT grease the pistons...I know, I know, I feel really silly for making a huge noob error. But after a lot of cleaning, honing and correct rebuilding, we put the like-new calipers back on, bled the front and POOF! BRAKES!

THANK YOU to everyone for your tips and help, especially to you Xtreme! That custom power bleeder was a great help!

JonnyBoy

Hehe...NooB.

Just kiddin, go jump it!

wyoming9

iTrader: (1)

I thought I had nailed it when you mentioned the pistons were dirty and you didn`t use the hone word the only thing the bores should ever see is just a very light coating of brake fluid .

Glad you got it sorted out.

That is why I don`t mess with rebuilding calipers it is hydraulics and in working with that stuff being clean is a whole new level.

I also on my fleet of Toyota 4x4 Vehicles have never bleed the LSPV because my one attempt resulted in a new LSPV needing to be bought that was a very expensive brake job

xxxtreme22r

Yeah not to mention the corrosion issues that me and wyoming9 have to deal with it. It's almost never worth it to tear apart these calipers. I did on mine, but I still have some minor issues with mine. Summer will bring new ones for me.