Wagon pulling to the right when braking....

[thrashingcows]

I've been trying to figure out why my right side front disc brake is applying faster then the left...or maybe it's the other way around? I have done a 73 C-body disc brake swap. Running a power brake set-up with an aluminum master cylinder from a mid 80's dodge truck/van. Front brake lines T'd straight off the rear port. And the back brakes are on a SSBC manual proportioning valve.

The rotors are new off shore units...drilled and slotted. I installed them last year and this problem seemed to show up then. I don't recall the brakes doing this with the stock rotors and pads. That is the only thing I changed...new rotors, and some semi-metallic pads that came with the rotors.


I have pulled the calipers and front brake hoses. Replaced the front brake hoses with new Dorman hoses....no change. Pulled the calipers and cleaned all mounting surfaces and put never seize in these areas. Also new pins and lubed the rubber bushings so they slide like butter. Still no change. You can physically feel the difference in drag when the car is in the air, with the front wheels off. You can spin the rotor much easier on the LH side, compared to the RH side. The left side feels "right" with just a small amount of drag....the right side is too much in my opinion. With the calipers removed the rotors both spin freely to about the same degree. It's once you re-install the brake pads, and then bleed the brakes that the drag starts.

Thoughts...opinions?

 

[commando1]

The spindle nuts are not tightened equally. Easy thing to overlook.

 

[thrashingcows]

The spindle nuts are not tightened equally. Easy thing to overlook.

I have spun the rotors with the calipers off...they both spin with the same resistance. I have also pulled and pushed on them with teh calipers off...same basic about of movement.

 

[commando1]

Which way does it pull when braking.
The side it pulls to is grabbing earlier.
On that side, back off another turn on the nut and road test it.

 

[Fredo]

I'd be looking at the rotors. If they are off shore and made in lots of thousands it is possible they have a "SLIGHTLY" different thickness. One maybe fatter than the other, grab your micrometor and check them out.
Of course I'm only guessing and typing this while drunk off my azz....

 

[commando1]

A fatter rotor doesn't grab any different than a thinner rotor.

Posted via Topify using Android

 

[thrashingcows]

I have to agree...That is why they are a floating caliper, with a fair amount of travel on the caliper piston. This way they can adjust to a wide range of thicknesses on rotors and brake pads.

 

[Mr C]

Any progress? I'm stumped and will be interested to hear the repair.

 

[thrashingcows]

Any progress? I'm stumped and will be interested to hear the repair.

Nope haven't figured it out yet. I'm leaning towards a bad caliper. If that does not fix it then I might try new bearing and races. And finally I will have to check the spindle...maybe it's been tweaked from an old accident?

 

[66SportFury]

Is the pull when you apply the brakes? If so, bad caliper. Sounds like the piston is hanging up. If it's pulling all the time, it could be an alignment issue or a tire issue. I've seen cars pull bad from a belt twisting inside the tire. Also remember if it's pulling to the left, it would the opposite side that has the issue 9 out of 10 times unless the piston is stuck causing the brake pads to be applied without pushing the brake pedal down.

 

[70bigblockdodge]

my guess is caliper alignment the wheel with less drag is probably the culprit pads are releasing/dragging less because caliper is slightly twisted this would show up as uneven pad wear if you where driving enough to wear them out. The side that its pulling toward is probably working properly the other side is releasing too much, taking longer to start braking. I would measure caliper to rotor distance on out side pad, maybe with pad removed caliper back in place. If the tight side is noticeably tighter then that is your problem but I think you ruled that out i.e. not to tight. My two cents.

 

[thrashingcows]

We all basically know the feel of properly installed calipers and pads dragging on the rotor....the LH side feels exactly right. It's the RH side that is too tight. I have been think, and racking my brain for some time now....and I think the problem has existed even before I swapped out the rotors and pads.

I got to thinking about things and I remember there always being a bit of bearing grease escaping around the dog dish cap on the RH side. Which leads me to believe that the pads are dragging and causing too mush heat build up, which in return is heating up the bearings and grease. Which then leaks out past the bearing dust cap and out around the dog dish cap.

 

[70bigblockdodge]

Yeah I was just putting out another idea with the caliper alignment. if you do have a slightly sticky caliper sometimes its worthwhile to just rebuild it long as its not leaking or a total ball of rust, rock auto has kits I'm sure.

 

[73 T&C]

Does it pull equally cold or hot?

Had this one happen to me... But only after I used the brakes a bit.

Left rotor was sticking and not applying pressure equal to the right...

I ended up needing to change the left caliper.

This is solved my problem.

 

[livininharrow]

Nope haven't figured it out yet. I'm leaning towards a bad caliper. If that does not fix it then I might try new bearing and races. And finally I will have to check the spindle...maybe it's been tweaked from an old accident?

it may be that you do not have all of the air out of the one caliper. just a thought.