The Black Hole

[gmanpaint]

Ok, appreciate the input.

I moved the rig over in the driveway. Brakes barely work. At idle, it holds but pedal is to the floor. Give it gas, and it pushes right thru the brakes.


I tried the rod 2 turns out, nothing. Tried 4 turns out, no change.

Pump up the pedal stiff as a board with engine off, hold pressure, start engine, pedal drops to the floor.

Been working on the rig since 8 am, non stop, no food, and it is now 6pm. I'm done for the day. Just got my old ass kicked again, by something that beats me everytime.

Going to try to take the day off of work tomorrow, and keep at it. Shops here are slammed, and always takes a couple weeks to get in, so that's out for the trip.

Thank you everyone for the help, means a lot to me.

 

[Rick]

Did you bench bleed the new master cylinder before installing it?

 

[gmanpaint]

Did you bench bleed the new master cylinder before installing it?

Yes. Was done properly.

We bled the system in proper order, a few times, and no bubbles in the last couple of tries.

So reading back about 10 years ago and the brake issue posts from back then, someone mentioned firewall flex can cause this issue. I don't understand how, but the firewall does flex some when pumping the pedal. Not sure if this is the demon I have been chasing or not. I wouldn't even know how to remedy that. lol

I am going to see if I can find a simple dial prop valve tomorrow, and swap this one out.

 

[CDW6212R]

There is a desired clearance for that rod, it may need to change length quite a bit from where they had it installed. It might be good to research that spec to see if it's close where you have it at.

 

[CDW6212R]

Watch the firewall flexing near the mounting points of the parts there. I hadn't heard of a booster deflecting too much, give it a look.

The accelerator pedal has a known firewall issue with the pedal bracket spot welds. Those two spot welds can and do crack, and then the bracket is deflecting away from the firewall, and you lose cable movement. I have repaired two of my Explorers, my 99 and my last 98. The repair is to drill two new holes nearby and spaced so a large washer headed OEM bolt will hold it together strongly. I used spare bolts, like the OEM 8mm fender bolts, and similar OEM nuts with large washers built into them.

 

[gmanpaint]

That's an easy fix!
I was thinking dash comes out, and weld. Lol Thanks!

20 hours and hundreds spent on these brakes, and 2 little bolts might help. Beyond comprehension. It looks pretty nice, but looks don't get too far out of the driveway. Smh

 

[410Fortune]

I sent you pm
My money is on bad master cyl
If a master cyl is depressed too far during the initial bleeding process it will tear a seal and you will get the pedal you describe.
No bleeding will fix it is very likely you need a new MC
NEW not reman
If you just bought one, take it back and try again...
Bench bleed only a little bit, don't kill yourself trying to smash a screwdriver in there.
Why? Because you know better then to press the pedal all the way to the floor now....not until the first few bleeds have been done......any air in the with the pedal seeing full travel and BLAMO torn seal
Ask me how I know
About 5 cans of brake fluid and 2-3 master cylinders later I finally had BII brakes again...we were mashing the pedal to the floor right away....turns out that is not a good idea. That was not the last time Ive seen this either
All of these Ford trucks have some amount of deflection in the firewall, the brake pedal is not known to have issues in the Gen II, not like the acc pedal, but when you are having pedal travel issues it is always a good idea to inspect the whole assembly, there should not be any play in the pedal, bushings, pushrod, etc
Adjusting the pushrod is not likely going to help you here....that only messes with the front to rear brake bias

Of course it is poss you have air pocket trapped in prop valve?
Old soft/ swelling brake lines
leaking between master cyl and booster
booster if it holds vacuum chances are its still good.....

google search brings up many examples of this
Here is the best explanation I have found, Miata forum:

" Certainly when one of the bleed nipples is open and you press the brake pedal to the floor, the piston in the master cylinder travels farther than normal. If the inside surface of the cylinder is "pocked" or has an irregular surface, it could tend to wear the edge of the seal as it moves over the roughness "

Good fix? PUT A BLOCK OF WOOD behind the pedal for the first round of bleeding so the pedal cannot travel to the floor

 

[410Fortune]

"A) If I simply remove the aftermarket prop valve, and just use a union to tie that line together, and run without any prop valve, I wonder if the rears will lock up easily? "

NO it will work fine! My BII has been setup this way for years.
5.0 booster, 95 explorer master cyl with no cruise and no prop valve. Straight brake lines to all 4 calipers, rear disc brakes
Works AWESOME
No abs, no Rabs no prop valve

 

[gmanpaint]

410, I Replied to your PM sir. Thank you very much!

Someone (TJ) brought up the booster to me elsewhere, and I think I am going to change it tomorrow as well. My brand new 4.0L booster was swapped for a used 5.0L booster with the engine swap, and I have had others tell me the 4.0 works just fine for the 5.0, and not necessary to swap it. They aren't expensive, just a PITA for me to replace squeezing under the dash, even with the seat removed.


I will try no prop valve before I buy another, thanks for that affirmation. I have also read from others, that they do not run one with the ABS delete, like I have done.

I am eliminating things again, and instead of thinking of it as throwing good money at bad, I am going by the mindset of hey, all new crap now. lol

I did ask my peddle helper NOT to depress all the way when we did that today, for those reasons. He is returning tomorrow night after work to help me bleed once again, and I will ask him about it, before I go swapping the New ( not reman) master again.

 

[410Fortune]

We have been going back and forth in PM's, here is the skinny:

No prop valve needed the correct proportioning is built into the master cyl

The booster is fine, if it hold vacuum and gives a woosh sound then its boosting.

He found a couple of drops of fluid between master and booster = probably a leaky seal in MC from being "bottomed out"

The pedal sinks to the floor with engine running because you are now boosted, your leg is strong enough to force the leak
With the engine not running it is hard pedal, but I bet if you pressed harder it will still sink to floor because its a leak in the new MC

Remove the proportioning valve dealio, it is not needed.

Put the pushrod back to stock length, so the rear brakes do not lock up early or drag

Bench bleed new master just a little, then finish the bench bleed in the truck, just do NOT press the pedal to the FLOOR until ALL air has left the MC (after one full bleed cycle on all 4 calipers) THEN you can press it, mash that sucker down.........

Just my advice after being through this a few times on these trucks....new master cylinder = pedal goes to floor = bench bleeding went south and new MC seal is torn.

Given this info:
4 new calipers
all new brakes rotors, pads, etc
All new soft lines
ABS delete
4.0 booster
Napa master cyl
booster holding vac
No other leaks in system
Found some fluid between MC and booster (chances are it did not spill into that are from filling the res because that area is sealed = no fluid can drop down in there....that fluid came from the master and is your leak = why the soft pedal

Thats my story and im sticking to it!!
My BII has been a good teacher, frustrating at times, but the school of hard knocks will learn ya well!

 

[gmanpaint]

Thanks 410.

I will return the master, and get a new booster. I have no idea if the old used 5.0 booster push rod was set to stock length and no idea what that length is. Hopefully they come preset.

My thinking on the masters with or without prop valves has been backwards all these years.

Every master I have bought, has been without prop valve, as I thought that meant the rig had a prop valve elsewhere.

I have been setting the aftermarket prop valve to 400 psi as anything higher seemed to cause the master to bypass, and thought that was why the pedal dropped on hard press.

A few years ago, I did a test and pinched both rear soft lines. The brakes worked and pedal was better. I had the prop valve set to 550 psi then. Turned it down to 400, and it worked better, but still had a soft pedal.

I really think that having that master without prop, and the inline prop, is one of the issues. That and been bench bleeding it until no air bubbles, plus putting the pedal to the floor on initial bleed. Never knew that was a bad thing until now.

Hopefully I can get my friend back over, to help bleed again.

 

[gmanpaint]

Just called napa. I got the last master they had in the state.

They can get another shipped, but will be 3 to 4 days at the soonest. Too late for me as the trip is in 4 days from now. They said they will refund me for it.

So now, I have to use one from o'Reilly or autozone, if I want to do this today. I really dislike both those stores for masters, but it is what it is at this point.

 

[CDW6212R]

The O'Reilly's used to have almost all the same parts choices as anyone, other than in house brand stuff. I'd start there and ask to know what all brand possibilities are, not just the lowest or highest price. It could be they have the same MC, since so many parts are made by the same companies.

 

[gmanpaint]

Ended up with the O'rielly New select lifetime (or 100k miles) brake master.

Bench bled it softly, and only used 3/4" to 1" strokes. Got the majority of the bubbles out, and stopped when there was just a few small ones left.

Eliminated the prop valve with a conversion coupling M10-1.0 to 3/16", to tie the lines together.

I set the push rod on the used 5.0 booster back to where it was, and put a smidge of bearing grease on the end, to eliminate the squeak they make sometimes.

Had to reshape the lines a bit, but took my time, and all went well, except that one time when the wrench hit the positive terminal, and a spark shot out the back of the booster at the firewall! Glad I didn't have the cruise, or low fluid level connectors hooked up yet. lol

Taking a break, as I wrenched my lower back pretty good, and hurts standing up or bending over right now, like a lot. Hell getting old!

I will give it a slow gravity bleed for a couple hours, with a tube in a bottle off all 4 bleeders. The fluid bottle feeder that stands on the master resi, sure is handy for this.

Hopefully, my helper can make it over tonight, and we can follow 410's bleed procedure. Crosses fingers, toes, arms, and the neighbor gals legs for good luck.

On another note....

The power steering fluid leak is getting worse. Helper & I looked at it as best we could to try to source the leak point. Best we can tell, it's leaking out the top of the rack, at the splined input shaft. There must be a seal there, and probably went bad (shrank) from this rig sitting so much.

Thinking of removing most of the fluid from the resi, and adding Lucas power steering fluid. It worked wonders on the 94 Ex seal, and swelled it right back up, stopping the leak.

 

[CDW6212R]

Good luck with the brakes, we all hope it works this time.

For the PS I like the additive Lubegard makes. There are many brands of course, use what you have or can get quickly.

 

[gmanpaint]

Help couldn't make it over tonight for the pedal bleed, and said he will try tomorrow.

So I tried the pedal after it gravity bled for a few hours. Engine off, pedal was stiff at the top of the stroke. Engine on, pedal falls right to the floor. Was really hoping that the gravity bleed would do it, but nope.

Plan is to buy a new booster tomorrow morning, and have it on standby in case the pedal bleed doesn't work. It's the last known used mechanical component left to change out. If I don't need it, I will simply return it. I'm almost out of time to get these brakes ready.

Son has in-laws flying from Chicago to AZ, to help with the 2 babies while he is gone. That was an ordeal as the daughter in law isn't happy about him being gone for so long, as he helps out a bunch with the grandchildren. He needs to know by tomorrow if the trip is on or not, so they can cancel the flight or not. No pressure here, none what's so ever!

 

[410Fortune]

Ill watch the babies

 

[gmanpaint]

Helper arrived first thing this morning. He had the day off, so we got an early start.

Bled the system the first time with the a short 2x4 behind the pedal, engine off. They pumped up no problem, but when we tried after bleeding, with engine running, the pedal fell 3/4 of the stroke with no resistance.

Bled it a 2nd time, no block, engine off, no bubbles came out in all 4 calipers. Same pedal deal.

Bled it a 3rd time, engine running, same deal, no change in pedal stroke.

They seem to work, but that 3/4 drop has me concerned.... like a lot. This is how it was before I decided to do all this work. So basically, no change at all after all this work.

I am going to go get that booster, and change it out. My back is screaming at me right now, and my brain is yelling at me about stuffing my self, all contorted under the dash. I will check for fluids behind the master when I do this, just to make sure it's not bad out of the box, or I blew the seal bleeding it. Ugh.

I'm really at a loss on this, & has put me in a funk.

 

[CDW6212R]

Keep that little MC pushrod in mind, its adjustment does have a big affect on the application of the boost and pedal. Try to go slow and patiently, keep thinking about every step without rushing or mistakes. I'm sure eventually it will work out.

 

[gmanpaint]

Couldn't take 2 days off work, but managed to take a half day.

Current situation