The Stovebolt Site Forums The Shop Area Driveline 41' 1 1/2 ton Brakes at the end of my wits

I have bleed the brakes, bleed the master cylinder, adjusted the shoes. Still the pedal goes to the floor. Where can I find replacement lines, or can a novice make my own?
If I can make my own could you direct me to a tutorial.

Thanks and Happy 4th!!

Andy

Hy TK421, did you bleed the hydrovac before bleeding the wheel cylinders? Did you bleed the lines longest to shortest, or use the procedure in the maintenance manual?

No hydro vac, Bleed longest to shortest

yes you can do replacement lines. However, brake lines should be double flared and some of the Chinese double flare tools are not worth 10 cent. A good repair shop will probably have a good double flare tool that would do them for you for a very minimal charge, maybe no charge!

..OR you can figure out the lengths you need and buy ready made lines from the local parts store. They have different lengths and I have did several systems and never even had to make a flare. Yes, you can do it.

....do you see a line leaking??

If you don't have a leak, replacing the brake lines won't solve the problem although I am definitely a fan of replacing old brake lines. I like using the copper nickel style lines. They are softer and easier to seal.

I have a cheap double flare set and I could never grasp the tubing well enough to do the flare. I have since obtained a better set and I can do flares no problem. The good set has a heavier clamping setup. As an experiment I put my cheap tool in a vice to help with the flare and it worked.

I would say that if you can get a good pedal with two quick pumps, it usually means a shoe adjustment problem. Also if you put the parking brake on, that usually shortens the stroke. It would be good to try as an experiment to see if you then get a pedal.

With no leaks and no pedal and properly adjusted shoes, I would think you have a master cylinder problem.

TK421, I had the same problem with my IH grain truck, blead the brakes till I was blue in the face,limped it over to my mechanics shop and he checked and found wrong cap on M.C. And he tried,same results. After much trying and reading and talking to other people they suggested trying reverse bleeding. I had never heard of this but he basically tied into rear right lower brake cylinder and pushed fluid instead of pulled fluid,long story short it worked. maybe that will work for you,at least it is worth a try. Pat

Bleeding brakes to remove air. Simple right? Not so fast every one. Start at the beginning. Yep the MC. Any pits? Dirt? or check valves? There are more to these critters than you think. next and even less obvious: Is there a "high" point in the system? Any place vertically above the MC? The obvious answer is yes! our beloved trucks have the MC down under the floor..that means the flex hoses are above the MC. Several other locations are up as well. So you must push fluid over and past these areas. That brings back the MC and volume. So to be helpful..maybe, Bleed the MC first(messy and unpleasant). All flex(rubber hose) must be in good shape. Then start at the longest line run..often the rear on the side away from the MC. But..sometimes the line runs over the cross member down the far side and..the driver side rear is in fact the longest run(gotta love that). Old school method involves a helper. Pump until some pressure is felt at the pedal. Hold and bleed. Repeat until the fluid that comes out is a "solid" stream(irony in language). Move to the other rear and do again. Move to the front(farthest) and do again. Finish at the last wheel.. Now, wait. Grab a drink..any one you like. Hit the pedal 1 time. To the floor? Adjust shoes(as a beginning gambit). Check the pedal travel at the MC. Does it move for the proper range? Does the fluid in the MC recover? The position of the piston and the holes in the MC must work together to move the fluid in the system. You should get a good solid stream from the last wheel as you bleed the system. Then the system should be at least air tight. Dual chambered MC? Front is separate from the rear, and the bigger reservoir is the front. Proper travel on the MC has cured many mystery brake issues. Enjoy!

If one has either residual valves in line or inside the master cylinder I don't think back bleeding will work.
Is you master new or old? Could you have a bad seal inside it which allows fluid to get around it. Although a pain, you could put metal plugs at the outlet ports. If the pedal goes to the floor then the m.c. Is bad.