Hey guys.
So I finished putting the IDI and ZF in my truck and it drove pretty well, but it didnt stop from what I thought was my rear wheel cylinders. So i decided not to mess with it and just do the disc conversion.

I finished everything and to be honest the truck stops a little faster but I still have to stand on the brake pedal to get it to stop. I replaced the front pads (didnt turn rotors, but I never have and have never had problems either). When I stand on the pedal it will go halfway, then will slowly sink to the floor, as iff the vacuum pump is trying to catch up. I gutted the residual valve off of the master cylinder. I adjusted the shaft on the brake booster to make it have no free play between the MC and booster. I even preloaded it about an 1/8 an inch and it stopped really fast by locking up the rear, even the RABS engaged, and had no pedal drop. But then after about a minute of driving the brakes started smoking (the rear ones, fronts werent so bad), so obviously the booster shaft was adjusted out too much, or the RABS was stuck on and applying. Now the rotors are blued on the rear, but whatever.

Long story short I have no clue why the truck wont stop. I have the same type of brake pads front and rear, they are second best semi metallics from advance auto. I was thinking about doing a hydroboost conversion but then I read this... Hydroboost conversion....done w/ pics - Diesel Forum - TheDieselStop.com and this.... Hydroboost install done!! I guess I'll try a Parachute!! - Diesel Forum - TheDieselStop.com

I was wondering if I used a 99-04 booster and master cylinder if it would work because they're actually meant for disc brakes (or the 97 superduty combo...originally I didn't think they had disc brakes).

I'm about to put an adjustable proportioning valve to the rear because I think the rear is getting too much pressure but I was wondering what some of you may think is up. I bled everything (even the RABS), the MC is new, no leaks in brake lines.

Thanks in advance

 

What condition are the front rotors in? How old are the front flex lines? Does your truck have single or dual piston front calipers?

I had similar problems with the brakes on my old F150, a steel brake line blew out which led to replacing all the brake lines and I figured I'd do the front flex lines too. WOW what a difference that made. Also had a problem on my car with weak brakes and turns out 1 piston in a dual piston caliper was seized. Bottom line is a small problem can make a big difference.

 

The front and rear flex lines look pretty old. The front calipers are dual piston, but they moved in freely when I pushed them back in to install the brake pads. They warm up too, I just haven't IR gunned them to see if they are equal or not. I assume if they are equal then I can rule out a sticky piston. (also to add to that, the truck does not pull hard in any direction, so again I would bank on equal pressure being properly functioning calipers) I can see the flex lines making a difference. I have heard of flex lines when deteriorating can have the inner layer fall apart so that they pretty much make a one way valve. When depressed it allows flow to the brakes, and then released the deteriorated rubber flows back and stops the flow back to the master cylinder. But have personally never seen this nor believe it would cause my rear pads to stick and my front brakes to not help in stopping.

Ive heard the RABS will sometimes retain air and sometimes they stick, so that would make the most sense. any tips for bypassing besides cutting and putting a compression fitting in? I want to be able to reverse it if it does end up helping, because i enjoy having ssome sort of ABS. I dont think they have female to female brake flare fittings ...