Solved Still NO brakes!

[IronCurtain]

95 Exploder 4 dr v6 Eddie Bauer..I'll try to keep this short...So driving one day and brakes almost go to floor all the sudden. Find a hole in the line above the rear axle. The brakes go almost to floor, but I can still stop. Most of the fluid leaked out but not all. Front brakes are obviously still working a bit. I drove it like that for a couple weeks, until one morning I'm driving to work and come off the highway, and I almost couldn't stop, it takes an extra short distance maybe 25 yards. Couple miles down the road I lose the brakes completely and have to coast to a stop. I refill the m/c reservoir, no additional leaks anywhere, but most drains out the hole in the rear.

I replaced the line from the m/c to the rear axle, the rear axle line, both rear brake hoses. Still NO brakes. Can't bleed any calipers because valves are all rusted off.

So I replace both front calipers and put in new pads. I bleed both front calipers, and get fluid out of both banjo bolts in the rear. Still NO brakes. Replaced m/c after bench bleeding it, bled both front calipers and kinda bled at the rear banjo bolts. Went thru 2 big bottles of brake fluid and alnost 2 hours bleeding. Still NO brakes.

What could be wrong? Why did the front brakes die all the sudden after they'd been stopping fine for weeks after the rear brake line went? Even if I can't bleed the rear brakes properly, if I bleed both front ones shouldn't I get SOME brake stiffness and stopping power? The pedal just goes to the floor every time I press it, with engine on or off, reservoir cap on or off. If I press the brake pedal a few times it never gets rock hard like it's suppose to. I'm at a loss. Going to have to replace the rear calipers and pads, so I can properly bleed all 4. Also I guess ill replace the power brake booster?

Could air in the abs system cause me to have NO brakes at all? Even when I have pedal to floor and put in drive, car goes forward.

Thanks in advance for simply reading this, and also for any replies!!

 

[shucker1]

Serious air in there somewhere.

Do you have ABS brakes?

If so you have air in the ABS unit which requires a special electronic tool to bled properly.

 

[RandomNerd2000]

Bleed the rear brakes, you need to bleed all four wheels. Air compresses, liquid does not.

 

[Mbrooks420]

Bleed all 4. Then bleed them again. And probably again.

95 has 4 wheel ABS, and if it’s like the later second gens air in the ABS unit is a big problem like stated above.

 

[IronCurtain]

If I bring it to a shop, I know they're going to tell me I need new rear calipers, because even if I just want them to bleed the system the bleeder valves on both rear calipers are basically rusted away.

So I'll replace them myself to save $$, then bring the vehicle to the shop to have them bleed the ABS and the rest of the system?

 

[Mbrooks420]

That sounds like solid plan. You’ll have to make sure the shop you’re taking it too has the capability to bleed the ABS module.

 

[donalds]

I just used forscan to bleed it either the on demand self test to open the valves and run the pump or the bilateral controls to bleed one valve at a time and run the pump
Some people just drive it on gravel to purge the abs pump then bleed a second time

 

[IronCurtain]

Buy shouldn't I get SOME sort of pressure at least in the front, after I've bled 2 huge bottles of brake fluid and 2 hours of bleeding? I mean I can turn the hubs with my hands while my partner floors the brake pedal.

 

[410Fortune]

Listen, after one bottle you should know something is wrong and more bleeding is not going to help
It only takes a few cycles of the pedal to push enough fluid out any of the 4 calipers.
I have seen this before, let me ask you the new master cylinder you installed was it new or reman?
While bench bleeding did the plunger get pressed too far?

My guess is when you lost the rear brakes you also lost the master cylinder because you pressed it so far it blew the seals. Then you replace the master cyl and bench bled the new one, did it bench bleed okay? I mean it got nice and stiff before you hooked it up to the brake pedal?
What I am getting at is even brand new master cylinders can go bad easily if the dang pedal is pressed too far during the initial bleeding process. Its a pita but it does happen with these units. So tell us how did you do the bench bleeding process? I am wondering if the new master cyl is also bad? Seals blown due to the plunger being pressed too far in......

air in the ABS pump sucks but its not going to cause you zero pedal, you would still have some action from the brakes somewhere.......

 

[IronCurtain]

Thank you for your response Fortune! Feel like I'm going crazy. I bench bled it like this:

1. Inatallled in vise
2. Capped both outlets and cruise control
3. Filled reservoir to tippy top
4. Used long screwdriver and pushed only about 1/2 inch to 1 inch a whole bunch of times until zero bubbles showed. I had to top it off a few times, so I know it was working.
5. Removed old m/c
6. Installed new m/c making sure not to let it dip sideways or anything.

During caliper bleeding procedure, when my partner pushed brake pedal (3/4 way down) fluid level in m/c drops, then when pedal is released fluid level goes back up. Not a whole lot, but definitely noticeable.

When I took old m/c off, for ***** and giggles I tried bench bleeding it with same procedure as above, but zero bubbles came out and I could hardly even compress it.

Could power brake booster be the issue?

View attachment 164747

 

[410Fortune]

well done that is a good way to bench bleed.
No the booster will not cause this because you should have hydraulic pressure even without being "boosted"

It seems like you have a trapped air bubble or blockage in the brake lines OR the new master cyl is already bad (been there done that)
Maybe try opening all 4 caliper bleeders and let it gravity bleed for a few? Does fluid flow if you open the bleeders fully?

When you put the new master cylinder on you said the pedal still went to the floor? This can ruin the seals in the new master cyl
Did you replace the rear calipers also or are the bleeders still rusted closed?

You should have some front brakes by now
air can be trapped in the ABS pump for sure
Bleeding backwards (meaning pulling fluid from each caliper) maybe a good idea...if you have a vacuum pump? self bleeder?

 

[IronCurtain]

Thanks again for response! I have to put new rear calipers in, then I'll just open all of them and let them bleed for a bit, but I'll buy a vacuum pump first and try to get the air out that way. I'll need to find a write up on it but should be fairly easy. On lunch break now, but back to work. Sucks cuz I'm having to get a ride from the boss to get to work. Sucks!!

 

[IronCurtain]

Also I know if i open the rear banjo bolts, fluid will come out on its own. Not sure about the front caliper bleeder valves.

 

[CDW6212R]

The power bleeders by Motive are better than the vacuum systems. I bought one from Amazon again last year, around $65 I think it was. Those are a one man tool, you attach it to the MC top, and pump it up. Then opening a bleed screw lets pressurized fluid out.

It sounds like there is a minimal amount of air at each rear caliper where the line break and banjo bolts have been loosened. That shouldn't be enough to end up with no pedal. As said, the little air trapped in the ABS also wouldn't stop some brake pressure from happening. It sounds like the MC you have on it isn't working properly.

Change the rear caliper, you must be able to bleed the brakes. Then try bleeding the system again. But expect to be R&Ring the MC again too.

 

[IronCurtain]

So what should be the first thing I do, right after I install new rear calipers, and another m/c? Do I pump the brake pedal 1/2 way? 3/4 way? What should I NOT do?

 

[IronCurtain]

Also: I have the old m/c off, is there a way to tell if it's bad? I plugged both outlets and cruise control port, filled the reservoir to the top, and tried to push in with a screwdriver but it hardly budges and no bubble or anything come out. Could it still be bad?

I'm also going to try to vacuum pump the front calipers before I install new ones in the rear, see if it does anything.

 

[Mbrooks420]

You need to replace and bleed the rears. Even if you get some pedal you NEED the rears to work or you are asking for an accident the first time you emergency brake. Rear brakes are critical for braking stability.

 

[IronCurtain]

Yes of course I'm going to replace rear calipers and pads. But not having those right now, I don't think, isn't causing the problem of my brake pedal going all the way to the floor and not even slowing me down a tiny amount. I literally have ZERO brakes.

 

[Mbrooks420]

You almost surely have a bad master cylinder. You also likely have huge air bubbles in them from crackingbthe banjos.

I’d do it all in one shot. The more you mess with it the more likely you are to have to take it to a shop to bleed the ABS unit.

 

[massacre]

If the fluid in the res goes down then comes back up, my vote is air somewhere.
Once you replace the rear calipers you will know better