No need for friction modifier, I have no LSD. Brake fluid is fine. No leaks, no change in the level. Just no pressure on the pedal. Brakes still work, just not nearly as well as they used/need to.

 

Bleed the brakes?

 

I second this, try bleeding them and checking the amount of pad left on the shoes/brake pads.

 

Is the pedal hard? If so then master cylinder and bleed are fine.

If you have lost braking effectiveness but not braking I think you have lost the power booster. Check your vacuum line to it.

Good luck,
- Jeff

 

I will definitely check those vacuum lines. Its strange really, when the truck is off, I have a stiff pedal but the pressure doesnt seem to increase. But as soon as I start the truck, pedal goes to the floor and brakes still engage just veeeeeerrrrrryyyyy sloooooooowly. What are the chances my check valve went bad?

 

So the vacuum lines seem fine, no visible or audible leaks. I just drove it around the block and it will still lock up the tires, just at the floor instead of a little further out like before. Fluid level is still the same and I haven't messed with anything. Brake pads have plenty of meat left but I haven't checked my drums yet(can't get my damn wheels off in the back) Sad part is, when I was living in Greenville, I would have probably drove it like this but in the mountains thats a no no. I don't want to go off the road up here and end up 100 feet down in some ravine. Stumped!!!

 

I wouldn't want to drive that anywhere... The last thing i could think of is air in the lines... That is the extent of my brake knowledge besides adjustments but that doesn't apply for the front i don't think. And if there was air in the lines it would have a spongy feel rather than going to the floor unless there was nothing but air in there... Which is unlikely.

All i can say is best of luck at this point, sorry.

 

How would I develop air in the lines all of the sudden?

 

You got me on that one, i doubt it is air, but my knowledge is limited so that is the best i can think of. It might give someone with more experience a better idea of the issue.

 

I had a similar problem with my 87 f-150 4.9L.....turned out to be the ABS dump valve. If they get even a small piece of grit in them, they can stick and cause soft pedals.

 

Where can I find this valve? I'm gonna check to see if I even have ABS.

 

i have a brand new detroit tru trac for the 8.8 i think 31 spline not 100% sure and 4.56 gears just sitting around i bought for a project but never got around to it. needless to say if u need something im looking to part with these brand new parts lol

 

Got a front gear too?