still have brake problems

[sootman73]

I still have brake problems. i would think that i should be able to lockup al four tires with all new lines(rubber and steel), a hydroboost conversion, newer rotors and pads, andproperly adjusted rear brakes.

I am thinking maybe the master cylinder or the power steering pump is at full capacity? my brakes seem to fade rather quickly after the first time i tough them and then it seems to lose brake power slightly and i have to push the peddle a little harder. i'm one that brakes early and doesn't like to hit the brakes hard.....

any other ideas?

 

[franklin2]

You may find the cheaper pads and shoes stop better than the lifetime units. The cheaper ones are sometimes softer and provide less life, but better stopping power.

 

[LCAM-01XA]

Do you feel the RABS kicking in at all? I agree that you should be able to lock up the rear wheels, the RABS will dump the pressure once that happens and will get them rolling again afterwards, but yes initially you should feel some sort of a lockup. Unless your RABS is wicked fast, that is, and at least mine ain't.

On the brake fade issue, I agree with Franklin, it sounds like it's related to the brake linings and not the pump or master cylinder.

 

[icanfixall]

What size is the master cylinder... The hydroboost uses a 1 5/16 inch bore. That will stop you on a dime and give you 9 cents change.....

 

[sootman73]

master cylinder is the regular f250 master. i guess i can put the 450 one on since the brake lines have been replaced. i just wanted to keep the seperate reservoirs....

 

[LCAM-01XA]

The hydroboost-specific master cylinder will make for a stiffer pedal, but it has less of mechanical advantage to it due to the larger bore (displaces more fluid volume per length of stroke) - if he cannot lock up the wheels with the smaller master cylinder, the big one ain't gonna help one bit.

 

[sootman73]

the only thing not brand new is the calipers and the wheel cylinders. oh and the rear shoes need replaced but i can lockup the rears on anything but pavement. i want to be able to lockup all four however..... should i find a spring from a lincoln for the powersteering pump? They hydroboost doesn't feel much different from a vaccumm booster. def no like everyone said it should be....

and it was not fun putting that system in and i didn't get any other repsonse.

 

[sootman73]

well i think i was making my front left brake into molten steel today on my way home. guess its time to replace calipers and pads... its the only thing in the front not new....

yea sparks were bouncing off the road surface all of a sudden and the caliper was on fire(i knew i kept that jug off water in there for a reason) and the rotor was red hot all the way around. looked like a monster truck pinion brake...

 

[LCAM-01XA]

ben, honestly my hydroboost don't feel much better than the vacuum booster either, in the brake assist department that is - my vacuum booster was just wicked strong, the hydro is stronger but not in a way that I'd notice in a daily driver. The pedal feel is where I really like the hydro, cause it takes the mushiness away and instead gives me a nice firm (not hard tho) pedal - I can only describe is as the feel of manual brakes with the power of real strong power brakes.

The Lincoln Mk7 spring and valve (should be the same as a Fox-body Mustang actually, as they share steering racks) does feel like it made the hydro a bit stronger, but not by much.

Locking up the front wheels on dry pavement is hell on the brakes tho, cause of the huge weight of the engine right on top of the wheels plus the weight transfer from the rear when you start the decel - I personally have experienced it only once when I was standing on the brake pedal and pulling myself on the steering wheel too (I can put down over 175 lbs of pedal force even tho I only weight 150 lbs), not anything you wanna be doing on day to day basis...

 

[sootman73]

hmmm i'm gonna replace my calipers tonight probably and see what happens. i dont have any problems with the rear brakes but i can tell the front brake aren't doing all they are supposed to be doing....

 

[MR.T]

In case you put new brake rotors on -- Double-check that the holes for the studs are chamfered enough for the radius on the non-threaded end of the wheel studs.

I was on the second one and noticed that the stud didn't bottom after pressing it in. Had to take the other side all apart again, press out all the studs and chamfer the holes properly. Very annoying.

 

[sootman73]

no i didn't replace rotors. they looked really good. they are only 6 months old. replaced calipers and everything is working much better. i think that the new slide pins that came with the set made a big difference!

 

[Wanderer-rrorc]

I fought the brakes on my f350 (92 4x) AND my E250 (85 2x)....

but I learned after the f350...after all new lines..all new rear hardware/cyl..I had a front caliper stick..so I swapped both sides...and that was where the problem was...dunno why..I have a pressure-bleader setup..should have gotten all the air out...

did the same with the van...shoulda locked them up..but didnt..so I swapped the front calipers out..and YUP...she's a STOPPER now!!

I almos suspect that the old units get a wear-groove in them and wont fully actuate..like a sticking caliper..just stuck mostly closed and wont slide all the way open..

and yes..I had already done the rubber lines before the calipers..so I KNOW it was the calipers causing the fault..