Have done complete brake job on 2001 b3000/Ranger. Have firm pedal when truck is off but soft when running. Thru reading etc. have come to think it's common need of ABS bleed. Have heard of different methods. One is using obd ii scanner with an make/model specific abs auto bleed function. Some are around $200. Other folks say drive it thru mud etc. to get abs kicking in. Anyone with this experience? TNX

 

Very very odd to get air in an ABS system.

Having air in just one brake line will cause the symptom you describe.

When you bled the brakes did you start at the passenger rear and then drivers rear and then passenger front and then drivers front?
So start from farthest away from master and move to closest

Do you have Rear ABS or 4 Wheel ABS?

Did you replace the Master?

 

My wife helps me and we've done 50+ cars this way and it works 100% every time. (many w/ABS)
The only car that ever gave me problems was a 95 corvette. It wouldn't bleed very well due to it having a bad ABS unit.

Here is what I do:
With ignition off "flush" all 4 corners like RonD says. Pump enough fluid through each corner until it flows as clear as whats in the bottle. (I used one big bottle to do this on my 98 ranger)
1. Starting at right/rear I open bleeder screw and let it drip into pan.
2. As the reservoir gets low I add fluid. Keep doing this until new looking fluid is flowing out.
3. Do this at all 4 corners. When done at each corner snug the screw tight enough so no air could flow back in.
4. Get helper in drivers seat. They push down on pedal until I say "OK". I open bleeder screw until nothing is flowing then I close.. then I say OK.
4. They lift pedal and push back down. Once down and holding I open screw until it stops and then repeat about 15 times. I do this until absolutely no air is coming out and the fluid looks 100% fresh.
6. NEVER let the reservoir get too low!!

****you'd be amazed how many "car guys" don't know how to properly bleed a brake or clutch****
Don't "bleed" the system. **Flush** it with 100% new fluid.

Brake fluid is hygroscopic and it has additives that need to to be 100% throughout the system.
Brake fluid at the master cylinder and at each corner doesn't circulate during operation. So what happens is 4 things.
1. The debris from seal wear and metal pitting continues to stay at the same place in each bore. As time goes on this debris suspended in the fluid accelerates wear of the bores, pistons, and seals..
2. The fluids additives break down.
3. Brake fluid is hygroscopic (absorbs moisture)
4. If hot enough it can boil inside the lines and degrade.

Here is a decent read --> https://blog.firestonecompleteautocare.com/brakes/everything-you-need-to-know-about-brake-fluid/

TIPS:
When engine is running, if the pedal goes nearly to the floor and you've 100% flushed the system... then I'd suspect the master cylinder has an internal bleed. (most likely the bore, piston, seal like I describe above)
When I "bleed" brakes almost all my friends can't believe I run that much fluid through it. What they don't understand is that brake fluid needs to be flushed. Not just remove the few air bubbles caused by changing pads.
Its not likely but I've seen hoses swell during brake. This can cause a softer feeling too.
If the fluid in the reservoir is dirty... don't let it flow through the system. remove it and fill w/new PRIOR to flushing system.

My 98 ranger doesn't have ABS but when I changed all 4 corners my brake pedal feels like a new car's. It's very firm and very typical new ford from the 90s feeling. (which I prefer)

 

Tnx.. 'preciate detailed steps,Mr. wydo! Have read also RonD reply to Rranger with sticky pedal .it's great that you take that time. I did not replace MC. I did the order you described. Although an assistant with me at another time did one closest,then the other front one, etc. Believe it is four wheel abs. I have had a couple of helpers but they could not be available for too long a time. So basically I'm looking for one man bleed advice. Tho that description can give me alot to work with need to do a version of it by myself. I have the Mityvac tool. Also a similar one from brakebleeder,com. Phoenix System they call it. Apparently can do different types of bleed including what they call RFI. Basically reverse bleed. Push fluid up from bleeder to release air out the MC. So I'm where I was decent pedal off;soft when running. Russell speed bleeders maybe as well. I really would like to get this myself.

 

Also see related topics below. This is a great forum. Tnx much for your time and input. I was a jet eng. mech. Air Force believe it or not. Deployed Desert Shield /Storm. But that was a long time ago. Never stayed in aviation and currently drive a pooper scoopa . Honey pots.lol! Good company great bunch of guys. At any rate been learning working on own vehicles more the last handful of years. Supposed to rain tomorrow or I would get to it. But might set up tarps anyway. I can read more threads etc. So it is odd for air to get in HCU of abs system. Does that happen tho?

 

Have someone push the brake pedal while you watch the rubber lines. You may have damaged a rubber line when doing the brake job. See if you notice any swelling when the brakes are applied. They age and can cause numerous problems. Reverse bleeding is far superior as far as getting air out of any sealed hydraulic system, but it's not often needed.