I am absolutely disgusted so please bear with me, after 2 days of bleeding and chasing down leaks my brakes still are not working in my truck, I search on-line and I find contradiction after contradiction about what I should be experiencing.

All of the information of what I am dealing with can be found on this thread https://www.ford-trucks.com/forums/1...-52-f-7-a.html but since most of the components are late model I am thinking I may have better luck getting suitable answers on this section.

If need be I can make another post with all of the details but it would be a very long post......my truck is truly a Frankenstein of parts, what I am up against is no brakes. I have bled thru 4 bottles of brake fluid correcting leaks ect and still after all of that no brakes.

I dont know how much this matters but if I pinch off the rear rubber line just above the diff it seems like the pedal will get rock hard and I have front brakes but I dont see why that is making a difference since my front brake line and my rear brake line do not junction at all at any point.

I have a rear brake line on one reservoir and a front on the other.

I am wondering, I have read this..........Simply plug the master cylinder ports and press the brake pedal. If the master cylinder is bypassing, the pedal will go down. If the pedal stops hard, the master cylinder is OK............Ok well I can plug my master cylinder ( which is what I did when I bled it as per the instructions ) and the piston will make its complete movement all day long, it never stopped hard until it reached its end of what I am assuming is its piston movement.

I looked at this because I am wondering if the pressure needed to overcome the 4 wheel cylinders in the rear is greater than whatever bypass is in the master cylinder and so its just bypassing the fluid right back into the reservoir instead of pushing out the 4 wheel cylinders.

I have no help, I am out here alone so its tough to see what is happening when I push the brake pedal.

Please help, I am at the end of my rope

 

Go back and look at the bleeders on the rear wheels. Are they above the hard line going into the wheel cylinder or below? If the bleeders are below, you have the wrong cylinder on the wrong side and they will have to be swapped. You will never get the air out with the bleeder below the hard line.

Also, how is the adjustment on the rear brakes? You should have adjusted them by hand while turning the tire, till you could not turn it anymore. Then back them off till they turn, but still rub a little bit.

 

Franklin....Thank-you for all of your help!

This is my left set-up and this is my right


I have read what you said above, it is possible that the bleeder screw went into the wrong hole, I believe it can go in either but this is the way the bleeders were set-up when I got the truck.

Although the last guy could not get it to stop either......maybe this is part of the problem, it makes sense but it will require me to bend that hard line ( that connects top wheel cylinder to bottom wheel cylinder ) I will go out now and see how hard this would be to do and report back

 

I have adjusted the rear brakes, I think I have them where they need to be.


I read this also on-line as a side-not.........Test for air in the system. A quick test that determines whether or not air in the brake lines is the problem is to pump the brakes 15-20 times. Hold down the 20th pump firmly while an assistant removes the master cylinder cover. If the fluid is jetted upward, then air has entered the system. At this point, you should bleed the lines by following the proper procedure for your particular vehicle................This is what happens when I follow this procedure, it will shoot up out of the reservoir.

Also read this ...............Plug master cylinder outlet ports. When the brake lines have been properly bled but the brakes are still spongy or dropping, remove the master cylinder lines and block the outlet ports. The desired result should be a full pedal. However, if the brakes are still spongy or dropping, or if bubbles are present in the master cylinder reservoir, the master cylinder could be defective and require replacing.............This makes no sense to me, its a new Master but if I plug the ports it will go thru its full piston travel, there is no hard stop until it reaches its end.

 

You answered your own q. The test says full hard pedal. Which means it may move a tick but not full stroke. If it goes full stroke and there is no leak around the line ports the master cyl is bad. New parts can be defective too. I once went through 4 dizzys on a isuzu before getting one that worked from advance.

 

I am trying to post the new picture but photobucket is not cooperating, I was trying to show you how this makes more sense since there is a bend in that connector hose that was made just to clear that big nut, anyway I was able to re-bend the steel hard line and now the nipple is above the inlet line.

Like I mentioned I did read this on the web but it was not specifically toward my vehicle and did not want to bend lines that should not have been bent.

Well maybe its time to re-bleed, whats another pint of brake fluid I guess.

Ok here it is now with your corrections

 

But the bleeding instructions say to cap off both outlet ports with provided plastic caps, fill reservoirs with brake fluid and basically keep pumping until no air bubbles appear but instead a nice steady stream of liquid from the bypass which is what happens.

Maybe I am mistaken on what is says, maybe I am all wrong?

I am going to be mad if this is the case! This is getting ridiculous, are you saying that after I block off the ports, put it in the vice, fill the reservoir, and I should pump it till no more air bubbles and the piston does not move?????

This is not how this one is working, please clarify

 

You guys are the best! Without your help this truck would have gone to the scrappers a long time ago, my patience is thin

 

Pretty much. You bench bleed the master cyl til theres no bubles. When the cyl is primed/bench bled it may move 1/4" if that and stop. That stop means all air is gone and the fluid wont compress.

 

The slack you get with a properly bled system is usually the vaccum diaphram or the rubber lines flexing from the pressure expanding it.

 

I think I screwed up then, here are cordones instructions...........

1. Tighten bleeder plugs into ports (bleeder plugs may be in parts kit or master cylinder reservoir).
2. Support the master cylinder in a vise in a level position. Never clamp onto the body of the master cylinder.
   NOTE: Units with remote reservoirs should be bled on the vehicle. It is VERY IMPORTANT that the body of the master cylinder be kept level during the bleeding process.
3. Fill reservoirs halfway or until reservoir ports are covered. Always use new brake fluid from a sealed container as specified by the vehicle manufacturer.
4. Install reservoir lid so brake fluid does not spray from reservoir during bleeding process.
5. Using a blunt tool or dowel (brake pedal if mounted in vehicle), SLOWLY press in and release the master cylinder piston using short strokes of 3/4” to 1”. NEVER STROKE PISTON MORE THAN 1”. Repeat this step until resistance to piston movement is firm and less than 1/8”.
   IMPORTANT NOTE: On step-bore master cylinders, WAIT 20 SECONDS BETWEEN STROKES. This will allow air trapped in the quick take-up valve to rise into reservoir. MASTER CYLINDER BODY MUST BE LEVEL.
6. Install master cylinder on vehicle. DO NOT remove bleeder plugs until brake lines are ready to be installed. This prevents air from entering the unit and brake fluid leaking out.
7. Remove one bleeder plug at a time from the master cylinder and connect the proper brake line to that port. Repeat this step for remaining brake line ports. Be sure fluid level is maintained during installation of brake lines and that all fittings are clean before installation. Bleed brake system according to vehicle manufacturer’s procedures and specifications.
8. Verify proper pedal action before moving vehicle. Do not road test vehicle until correct pedal feel and travel are obtained.
   NOTE: If firm brake pedal action results using bleeder plugs, but becomes soft after installation in vehicle, the problem is not the replacement master cylinder.

Step 5 I screwed up, I bled it by pressing in all the way every time, it says here ony 3/4 to 1 inch, maybe I messed up the master......These instructions were not with my master but mine is a Napa .............I have another one already on its way and will be here sometime tomm afternoon because I told Napa this one was not working properly.

How do I tell if I have a step bore master cylinder?

 

Here is my set-up as of this afternoon

 

Let me get this straight: You can plug your master cylinder lines and STILL push your pedal all the way to the floor? I've never tried what you stated above, but logic tells me that you shouldn't be able to do this as you can't compress a fluid. The only way you would get any travel out of the piston when the pressure ports are blocked off is if there is an internal seal leak in the MC.

As far as bench bleeding a master cylinder, I've always used the master cylinder bleeding kits, a vice, and a screw driver. I've also "bench" bled them on the vehicle, but I still used the master cylinder bleeding kit.

I think that in your change over to a dual reservoir MC is a great decision, especially from a safety standpoint. Do you have a picture of how your new brake plumbing is ran to the MC? I'm thinking that you might have a problem if your rear brakes are plumbed to the small reservoir (the front) and your front brakes plumbed to the large reservoir (the back). I'm not sure if the front piston will move enough fluid for your four rather large wheel cylinders. I could be wrong, and I'm not privy to the private conversations you had with others during your other thread.

Anyway, these are some of my thoughts.

 

Well, you've been busy posting while I was writing mine!

 

The net says a step bore moves large amounts of fluid. I really dont know how to tell the difference.