Break pull

[swamp rat]

On my K20 i installed a new lift kit, brand new springs front and back. Also, brand new calipers, disks, new ball joints, all new bearings. Rear got a disk conversion, all new hub bearings. Set my toe in to approximately 3/16 narrower in the front with 33" tires.

Initial test drive has the brakes pulling a little to the right when moving forward, in reverse it seems to stop pretty straight, looking for possible causes?

[hayhauler71]

brake hose?

[swamp rat]

Bump...

[motorcritter]

I would also suspect hoses, also, did the caliper slides get lubed (with a high-temp synthetic brake lube, of course)? Check the temperature of the rotors with a remote temp gun- if you've got a hose with internal collapse, the dragging brake will be hotter than the other side. If the hose is really bad internally, it can act like a blockage and prevent that side from operating freely, if its like a one way valve (the usual scenario), that side won't release and get really hot. Hoses get neglected quite often, and letting a caliper hang on a hose can cause a lot of misery, internal breakdown being just one of them. Good rule if thumb- if the hoses have cracking on the outside, it would be prudent to replace them.

[swamp rat]

Originally Posted by motorcritter

I would also suspect hoses, also, did the caliper slides get lubed (with a high-temp synthetic brake lube, of course)? Check the temperature of the rotors with a remote temp gun- if you've got a hose with internal collapse, the dragging brake will be hotter than the other side. If the hose is really bad internally, it can act like a blockage and prevent that side from operating freely, if its like a one way valve (the usual scenario), that side won't release and get really hot. Hoses get neglected quite often, and letting a caliper hang on a hose can cause a lot of misery, internal breakdown being just one of them. Good rule if thumb- if the hoses have cracking on the outside, it would be prudent to replace them.

Yep i uses silicone grease on the sliders, they release fine from what i can tell.

I should have added, i also have brand new brake lines from ORD.


Could it just be air in the line??

[Keith Seymore]

Originally Posted by swamp rat

On my K20 i installed a new lift kit, brand new springs front and back. Also, brand new calipers, disks, new ball joints, all new bearings. Rear got a disk conversion, all new hub bearings. Set my toe in to approximately 3/16 narrower in the front with 33" tires.

Initial test drive has the brakes pulling a little to the right when moving forward, in reverse it seems to stop pretty straight, looking for possible causes?

A couple thoughts:

a) Since it's pulling to the right you'll need to focus your attention on the left side. Since there is a finite amount of brake torque that can be generated the left side is deficient in some way (it's not that the right side is being an "over acheiver").

b) Since everything is "new" - perhaps the pads and rotors are not seated yet. I would give it some time and see if it evens out after getting burnished and settling in to place. OE manufacturers have a "burnish" procedure to make sure everything is seated and broken in before taking brake test data.

c) I would disregard your "pulls when moving forward, reverse is ok" data point. Brake pulls are proportional to the amount of brake pressure applied and magnified by speed and distance. Since reverse is typically a low speed manuever you don't develop enough brake pressure/brake torque differential to highlight any potential problems.

K

[TBONE1964]

Just another thought. Make sure the brake hoses are not twisted or looped. If one side is and the other is not, that will cause a brake pull. Check for air in the system again. Even though it may have bleed good initially, there is a chance some air in the system made it to the caliper.

I agree also with give it some time for everything to seat in. If all else fails, try swapping the brake pads from left to right and see if the pull changes direction.

[swamp rat]

Originally Posted by TBONE1964

Just another thought. Make sure the brake hoses are not twisted or looped. If one side is and the other is not, that will cause a brake pull. Check for air in the system again. Even though it may have bleed good initially, there is a chance some air in the system made it to the caliper.

I agree also with give it some time for everything to seat in. If all else fails, try swapping the brake pads from left to right and see if the pull changes direction.

I kept the hoses as straight as possible. I did my best to keep the pads clean of any grease ect, when i re bleed if i still have the problem i'll look into swapping the pads to not if the pulling changes. Thanks TBone.

[swamp rat]

Originally Posted by Keith Seymore

A couple thoughts:

a) Since it's pulling to the right you'll need to focus your attention on the left side. Since there is a finite amount of brake torque that can be generated the left side is deficient in some way (it's not that the right side is being an "over acheiver").

b) Since everything is "new" - perhaps the pads and rotors are not seated yet. I would give it some time and see if it evens out after getting burnished and settling in to place. OE manufacturers have a "burnish" procedure to make sure everything is seated and broken in before taking brake test data.

c) I would disregard your "pulls when moving forward, reverse is ok" data point. Brake pulls are proportional to the amount of brake pressure applied and magnified by speed and distance. Since reverse is typically a low speed manuever you don't develop enough brake pressure/brake torque differential to highlight any potential problems.

K

I do agree with you that the left side is deficient right now. I will have to drive it more to seat in the shoes.

Every time i post something i realize i could have included more information, i'm still waiting on shocks for the truck so only went around the neighborhood block, never went over 35mph reverse test was about 10 mph.

Thanks for your help!

[WIDESIDE72]

Needs new hoses. The lift doesnt have them in a bind, does it?

[swamp rat]

Originally Posted by WIDESIDE72

Needs new hoses. The lift doesnt have them in a bind, does it?

As posted above, brand new hoses, not bound up, was real carful if that.