Major braking problem

[rikkitikkitavi]

Ok so the m1009 started pulling left when braking hard, so I replaced both brake hoses, thinking one was weak and closing off. No change. Last night I did a brake job, no longer pulls right but after the 5th or 6th time on the brakes she pulled so hard right I went off the road and flipped onto the side! Flipped it over, got it home and changed calipers tonight, not as bad but still pulling hard right.....I am stumped.

SOS


Rikki

 

[CUCVFAN]

Wow! So, did you mean to say it pulled *right* to start with?

You have replaced the hoses and calipers at this point? Did the right side bleed freely, like the steel line was not plugged? Is the steel line pinched anywhere from the proportioning valve over to the wheel?

 

[ODdave]

Im still in astonishment that you "Gimp'd" it when you knew there was a problem....I will add something usefull when this passes.......

 

[rikkitikkitavi]

Wow! So, did you mean to say it pulled *right* to start with?

You have replaced the hoses and calipers at this point? Did the right side bleed freely, like the steel line was not plugged? Is the steel line pinched anywhere from the proportioning valve over to the wheel?

No it was pulling left to start, fluid ran freely from both sides, bled fine. Have changed both hoses, pads and calipers. Still pulls hard right but not consistently, Steering is also vague at times (seems to correspond to pulling right)

Hope that helps clarify! And thanks

Rikki

 

[rikkitikkitavi]

Wow! So, did you mean to say it pulled *right* to start with?

You have replaced the hoses and calipers at this point? Did the right side bleed freely, like the steel line was not plugged? Is the steel line pinched anywhere from the proportioning valve over to the wheel?

No visible pinch, flip over was on a way back, back road....got her home at 25mph on the back roads....no real damage, was only doing about 20 or so but the ditch at roadside is about 3 feet deep. Physics did the rest!

Rikki

 

[jaymcb]

all I can say to this is....wow...just....wow

 

[Buzz]

did you put the truck up on jack stands and have someone pump the brakes and release them, then try to spin each wheel and see if one drags more than the other. Also make sure your rotors turn free. Look for anything like wheel bearings ect. ect. anything that could cause a differance between the two sides. Also I will throw this out there, this was a late model gm truck with the hydro boost not a cucv, I seen someone put the wrong fluid in the master cylinder and comtaminate the system, it swelled everything rubber in the system and sometimes when this guy would drive his brakes would drag hard.

I dont know if this helps but sometimes things get overlooked, I know most times it is a line or caliper. You could try pushing the pistons back in the calipers and see if one side is harder to push back.
hope you find it
buzz

 

[Varyag]

We had a similar issue with an old cj2a at our ranch. Turns out that the lining inside one of the break lines separated and caused a bubble that would make a weird kind of valve and would block the break on that side and cause it to veer hard to the other when you braked. I had never even heard of that before then.

 

[rikkitikkitavi]

Im still in astonishment that you "Gimp'd" it when you knew there was a problem....I will add something usefull when this passes.......

Nothing to be astonished about, it was either nurse it home or walk 6 miles at oh-dark thirty, no cell service where I was, radio antennas are off the truck for mods. Its not hard to drive at that speed IF you know its going to pull if you brake...

UPDATE: Ok so I have been driving it about this AM and I have discovered that it pulls for a couple of seconds and then evens out and operates normally, the brakes aso work normally until they get warm.

THese parts have been replaced

Wheel Bearings ( both)
Brake Pads (Both)
Brake hoses (both)
Calipers (both)

the mystery continues....

Rikki

 

[doghead]

One place both the steering and the brakes are "connected" is the power steering pump. it supplies the hydo boost and the steering gear box.

I wonder how that could relate to your situation.

 

[Jersey4x4]

I had a bad steering box in my M1008 and it would jerk the wheel to the right after a turn. It pulled the wheel right out of my hands and I did notice before the steering problem when I quickly stepped on the brake peddle it would go down and give a quick jerk back up almost like a modern ABS system would do. I jacked up the front end and set the throttle at 1500 rpm and started playing with the steering wheel and id simulated the same scenario violently so I replaced the steering box with a new AGR super box and also the pump with the biggest AGR made and the hydroboost unit with a new one and has been fine ever since. I will guess the hydraulic valve in the steering box was bad and would allow it to steer buy it self and also cause pressure changes to the brake booster so I replaced it all to prevent any future issues of metal being in the system.

 

[militarytrux]

I had the same problem with my truck, turns out it was the hydro booster. it pulled so hard it took all I had to keep it straight. it scared the sh*t out of me when it happened no warning at all.

 

[ODdave]

Nothing to be astonished about, it was either nurse it home or walk 6 miles at oh-dark thirty, no cell service where I was, radio antennas are off the truck for mods. Its not hard to drive at that speed IF you know its going to pull if you brake...

UPDATE: Ok so I have been driving it about this AM and I have discovered that it pulls for a couple of seconds and then evens out and operates normally, the brakes aso work normally until they get warm.

THese parts have been replaced

Wheel Bearings ( both)
Brake Pads (Both)
Brake hoses (both)
Calipers (both)

the mystery continues....

Rikki

let me clarify. "Gimped" meaning flipped it.

 

[Barrman]

Check your steering components. Have somebody turn the wheel sharply 30° back and forth while you crawl around underneath and put your hand on each and every joint. Drag link ends, tie rod ends, rag joint, box to frame mount and then pick the front end up. Push/pull on the top of each front tire while somebody looks at both upper and lower ball joints for play. There should be none. Use a pry bar under the tire to see if the ball joints have any slop up and down.

If you feel any slop in the steering joints, replace the parts.

If all this checks out ok or you replaces stuff, get it aligned and the problem still happens.
Pull the power steering belt and take it for a drive. That will eliminate hydraulic influences on the steering.

While you may find your hydroboost is faulty, it has no direct relation ship to steering other than fluid flow. That means a bad booster is just a bit worse than your steering box. With brakes, a bad booster just means you have to push harder. It has nothing to do with side to side braking.

You did put on new parts, not other used ones?