Serious problem. Wheel lock-up

[ACUDANUT]

My 70 Charger LF wheel locks up going forward, but not in reverse.
I have replaced the rubber hoses to the front disk brakes, replaced the master cylinder.  It can't be the brake caliper because if it was bad, it would seize in both directions and the same for the brake portioning valve.  It will unlock after about 50 feet and I can continue driving.  I am at a lost.
I NEED REAL HELP HERE.

[BLK 68 R/T]

70 is the free floating pads. I would say something is worn causing the pads to grab, maybe at a weird angle and then not release normally. Not grabbing in reverse could be because there is nothing worn in that direction since it not used any where as much as forward. I would take the caliper off and do a good thorough inspection of the mounting holes, attaching bolts and slider area for the pads. Also thoroughly inspect the spindle where the caliper mounts as well.

[Dmichels]

when did this problem first happen? 

[ACUDANUT]

 2 years ago.  I am thinking maybe the bearings ?

[matrout76]

might be the brake shoes are on incorrectly

[BLK 68 R/T]

2 years ago.  I am thinking maybe the bearings ?

I guess it could be the bearings, if when you drive forward the hub slides out or something like that. Does it lock up immediately in forward?

[ACUDANUT]

2 years ago.  I am thinking maybe the bearings ?

I guess it could be the bearings, if when you drive forward the hub slides out or something like that. Does it lock up immediately in forward?   YES

Yes.  The brakes shoes are on correctly.  This happened before and after I removed the caliper and shoes, to replace the rubber brake line. 

[MSRacing89]

2 years ago.  I am thinking maybe the bearings ?

I guess it could be the bearings, if when you drive forward the hub slides out or something like that. Does it lock up immediately in forward?   YES

Yes.  The brakes shoes are on correctly.  This happened before and after I removed the caliper and shoes, to replace the rubber brake line. 

I would bet you something came apart inside the proportioning block or a blockage in that line.  It's holding residual pressure in that one line, that is why is feels like it pulls and also won't release for 50ft.  Replace the block and the line to the caliper.

[BLK 68 R/T]

I would do the following

1. jack the car up
2. see if you can manually turn the wheel
3. if yes have someone hit the brakes and then release, can you still turn the wheel?
4. if no, pull the wheel and take the caliper off, then can you turn the wheel freely?
5. if yes then the problem has to be with the brake system or the caliper.

also one other thing to check, and maybe I missed it, when going forward is the car going in a straight line or when you are turning or both when the wheel locks up? reason I ask is maybe if you are turning the line is getting pinched somewhere not allowing the caliper to release?

[matrout76]

can you post of picture of the brake shoes without the drum on?

Also, it should be obvious if it is a bearing problem when you pull the hub off the spindle.  The bearings and grease would have to be in really bad shape to sieze.  I had this happen on my first CJ-7 not long after buying it.  The PO had a shop put new brakes on the front before i bought it.  Being a 19 y.o. with a Jeep...i did quite a bit of off-roading.  while on the highway one day, one front wheel would lock up and then release.  I limped back to my apartment and took it apart in the lot to find that the shop didn't install any wheel seals so the hubs filled with water during one of my adventures.   

[redgum78]

Thats really odd for a disk brake to do that. Like others have said...jack the wheel up and spin by hand. Then apply brakes and do it again. It should be obvious if it is a brake issue or something else.

Does it get hot if you take it for a short drive?

[redgum78]

Just read your post again. You say you replaced your master cylinder.

I am thinking you may have fitted a drum brake master cylinder instead of a disk brake one.  Drum brake master cylinders normally have a residual pressure valve in them that will cause disk brakes to lock on and drag.

[ACUDANUT]

Just read your post again. You say you replaced your master cylinder.

I am thinking you may have fitted a drum brake master cylinder instead of a disk brake one.  Drum brake master cylinders normally have a residual pressure valve in them that will cause disk brakes to lock on and drag.

No, this was a issue before I replaced the Master cylinder.  That changed nothing. 
To all others, I will be back to work to figure this out. Thanks
One more thing, the brake hoses are installed correctly.

[BLK 68 R/T]

Good luck 
Interested to hear what you find.

[ACUDANUT]

Good news.  My bearings were flat in some areas and almost flat in others. The grease looked/felt like glue.  In the 30 years I have owned it, I never looked at them. However, I have only driven it less than 500 miles in that time.

[BLK 68 R/T]

Well at least it's an easy fix (hopefully) make sure to inspect the spindle while you have the rotor off and make sure the bad bearings didn't damage it. Same for the rotor.

[redgum78]

  hmmmm 30 years, have to check the service schedule but I think that might be a little over?

Glad you have got it sorted!