2nd Gen Non-Engine/Transmission Rear Brake lock up

[jdrury]

Well, i have got a problem with my rear brakes locking up. I have searched and read through about 20 pages of brakes problems, but none like mine.



It is a 01 2500 six speed four wheel drive with rear drum brakes.



The problem is - about 85% of the time the brakes work awesome, no problems with brake pull or wear. But if I am driving about 40 -50mph and have to do a quick stop, i hit the brakes, start slowing down, the brakes seem to release , get stiff for split second and then the rear brakes lock up - they actually skid the rear tires. I have never felt the abs kick in , but i will let off the pedal, apply them again and most of the time the same thing happens, pedal seems to release get stiff for a split second then the rear wheels lock up again. .



By this point I am usually slowed down enough or stopped, and i have not hit anything yet, but it sure scares the crap out of me and any drivers close to me.



I have pulled the drums off and every thing looks good - no excessive wear on the shoes, no dust , no axle seals leaking onto the linings, no wheels cylinder leaks and i have never had a problem with any abs lights ( although the abs seems to work fine - just had a snow storm and they actuated several times ).



Sorry for the long story, but this is driving me crazy. - Thanks

 

[bromano676]

is there any noise from under the hood. Power steering pump whining.



I just had somehting similar, thought the pump was on its way out. From new, it always made a little bit of a whine when it got cold out. Figured that was the problem, but after 2 hours and 100 miles, it never stopped. I checked the fluid and it was low, filled it up, now I have to keep an eye on it, until I find the leak.



anyway, when the fluid was low, the brakes acted kind of the same way.



just a thought

 

[T Peterson]

Probably not your problem but make sure those rear brakes are adjusted manually, they'll get really grabby if not adjusted. hope this helps. Tom

 

[Texis]

My rear drums are driving me nuts. I never had a problem over 320K... added a set of aluminum wheels with 1/4" spacers in the rear and now the rear end bounces when applying the brakes? The drums were turned twice by 2 different shops, then I replaced the drums with new, still bouncing? I will say the old driums were warped and the bounce is down by about 80%, but it still bounces. This is certainly bizzard thing to happen when you add some new wheels!



The truck "acts" like they are grabbing and releasing, which causes the bouncing effect. It is tolerable, but still not right. Taking a 1,000 mile trip in a couple of days... . maybe she will lath herself smooth!



As stated, this started the instant the new wheels went on... any ideas?

 

[Joe Mc]

Is the link from the rear diff to the hydro brake line thing (can't remember what the heck it is called) that proportions the amount of pressure going to the rears connected? Possibly a bad sensor in the diff? Although I know I replaced mine a few years back cause the speedo (I think) was acting up or the brake light was on? Of course mine's a 99 so it could be different than the 01 w/rear drums.

 

[B.G. Smith]

My rear drums are driving me nuts. I never had a problem over 320K... added a set of aluminum wheels with 1/4" spacers in the rear and now the rear end bounces when applying the brakes? The drums were turned twice by 2 different shops, then I replaced the drums with new, still bouncing? I will say the old driums were warped and the bounce is down by about 80%, but it still bounces. This is certainly bizzard thing to happen when you add some new wheels!



The truck "acts" like they are grabbing and releasing, which causes the bouncing effect. It is tolerable, but still not right. Taking a 1,000 mile trip in a couple of days... . maybe she will lath herself smooth!



As stated, this started the instant the new wheels went on... any ideas?

Are the tires on the rear the same diameter as the front tires???? bg

 

[B.G. Smith]

Well, i have got a problem with my rear brakes locking up. I have searched and read through about 20 pages of brakes problems, but none like mine.



It is a 01 2500 six speed four wheel drive with rear drum brakes.



The problem is - about 85% of the time the brakes work awesome, no problems with brake pull or wear. But if I am driving about 40 -50mph and have to do a quick stop, i hit the brakes, start slowing down, the brakes seem to release , get stiff for split second and then the rear brakes lock up - they actually skid the rear tires. I have never felt the abs kick in , but i will let off the pedal, apply them again and most of the time the same thing happens, pedal seems to release get stiff for a split second then the rear wheels lock up again. .



By this point I am usually slowed down enough or stopped, and i have not hit anything yet, but it sure scares the crap out of me and any drivers close to me.



I have pulled the drums off and every thing looks good - no excessive wear on the shoes, no dust , no axle seals leaking onto the linings, no wheels cylinder leaks and i have never had a problem with any abs lights ( although the abs seems to work fine - just had a snow storm and they actuated several times ).



Sorry for the long story, but this is driving me crazy. - Thanks

Try disabling the ABS by pulling the fuse or disconnecting a connector and see if it still does this? bg

 

[bmoeller]

I have found, that if the rears aren't adjusted up, the ABS won't work. Also, if it is a bit damp, they can get grabby if there is even the slightest hint of oil on them. Takes almost nothing. Was the wheel seal even the slightest bit damp? Not wet, but damp.

Were the lug nuts tightened with an impact wrench, vs a torque wrench? Rotors might be warped.

 

[jdrury]

Try disabling the ABS by pulling the fuse or disconnecting a connector and see if it still does this? bg

No, not yet, but that seems like it would be a good idea to rule out a few things. I will try to do that this evening and get back to you - thanks

 

[Texis]

Yes the tires are the same size, but the rims are 8" vs the 6 1/2" OEM they replaced. This has caused the tires to run in a different profile and there is a flat spot or two. The flat spots have been there a long time. The tires have 52,000 miles on them, at least another 20,000 left in them, plenty of tread remains.



Experiencing no braking problem on the front end? I isolated the brake problem by applying the emergency brake which effects the rear only.

 

[B.G. Smith]

Yes the tires are the same size, but the rims are 8" vs the 6 1/2" OEM they replaced. This has caused the tires to run in a different profile and there is a flat spot or two. The flat spots have been there a long time. The tires have 52,000 miles on them, at least another 20,000 left in them, plenty of tread remains.



Experiencing no braking problem on the front end? I isolated the brake problem by applying the emergency brake which effects the rear only.

My thought was, if the tires are different diameter it would cause the ABS to malfunction. With the wider rims the profile of the tire might be different enough to add to the problem. bg

 

[RLHannink]

My rear brakes will occasionally get a little grabby. I've found that it's the adjustment. My solution is to jack up the rear by the diff, leaving the tires on, and adjust each brake using this method:



-back both brakes way out so it'll spin easily with no noise (using a flat screwdriver and a smaller one to hold the clicker thing away from the starwheel)



-tighten the adjuster as tight as i can with the screwdriver



-back the brake off until it'll turn by hand, so that the brake makes just a little noise while turning by hand



-do the other side the same way. when I get it very even, it's way less grabby, actually pretty smooth. My parking brake is a little weak at that point, but I can drive it around just fine. I've found that NAPA Gold shoes are the smoothest, but they wear fast. I have to do this about every 5-10k miles.

 

[SSell]

when were the brakes last serviced? I know from experience if you pay more attention to that 12pack & your buddies' BS stories than where the long-vs-short brake shoes go you end up with rear brakes that tend to lock up very easily (even with a functioning ABS). Be sure the linings arent swapped!

 

[Texis]

Original rear drum shoe's lasted 290,000. This set has been on for 30,000 and basically shows little to no wear. The drums are new (2 days old) and my truck doesn't have ABS. It appears to be getting better, drove it 80 miles today and it bounced very little. It occurs in the mid pedal position. Light pedal = normal, heavy pedal = normal, in the middle = mild bounce.



Like many other things about my favorite truck, live with it... sometimes it goes away, sometimes you get accustom to it, sometimes you turn the radio up. Either way she just keeps on heading down the road.

 

[MarkMiller]

Light pedal = normal, heavy pedal = normal, in the middle = mild bounce.

Sounds like a slightly warped drum. Never get reman drums or disks. Always warp fast or come to you pre-warped.

 

[KYOUNG]

I would say your new drums are not 100% clean, oil from manufacturing process is still coming out of the cast iron. they will get better in time or pull off and BrakeKleen again!

 

[DieselDoghouse]

and just to add to the list - erratic brakes or 'locking' can be the result of a defect eroded into the inner lining of the brake hose (between the frame or any brake-rate proportioning device (ours were called height sensing valves) and the hard lines on the rear axle. The defect can act like a flapper valve - allowing fluid to move in but not out when the brakes are released. Tough to identify without just replacing the flex line…

 

[darom]

DD,is this applicable to earlier 2nd gen trucks (brake hose defect)? Thx

 

[Texis]

Is it posible my truck has "rear only" ABS? I have heard of this set up on some trucks. How do I determine? If so, how would I disconnect it to determine if this is the problem?

 

[DieselDoghouse]

Apparently, this is potentially applicable to ANY vehicle with flexible rubber brake hoses - frame to wheel or frame to axle. It is often overlooked until it is the LAST item addressed to resolve an issue. For some reason it is more common on Dodge hoses (no, I'm not HOSING Dodge - they bought em from somebody!!) than other makes—but by no means unique. I would just say before replacing Expensive parts, consider the hoses!!