2nd Gen Non-Engine/Transmission Hippty Hoppity - backend when braking

[Joe Mc]

About 15k ago I had the drums trued up as there was a bit of hoppin in the rear as brakes were applied (not anti-lock hop just brake hop) would go away as soon as you let off the pedal. I took it to my friends shop and watched each cut. Truing them up only lasted a few k miles then I brought the drums back and asked to have them checked. Ridiculous they had to be cut again - looked as if they were put on the machine wrong the 1st time there, as the cut went half way around then missed the other half until enough material was removed to get a constant cut. My friend has been doing brake stuff for a long time and surely couldn't screw up a simple cut job - heck I watched and know how it's supposed to be done and it looked rite to me. They trued up again and were fine - yes only for another few k miles. This stinks they're doing it again is everything on these blasted trucks junk except our beloved Cummins engines:{? Sorry, had to lift a safety for a moment.



Anyway 2 questions

1-How much and whom makes the "best long lasting ready to bolt on w/o having to be trued up first drums", need them soon please include part numbers if possible. Is there such a thing? I just did the front calipers a few weekends ago and rear shoes about 15 k back might as well do the drums now and,

2-Up until 2 weeks ago I used to use the emergency brake "EVERY" time I would shut down. Figured this might be screwing things up so I stopped. Could this have warped the drums, constant pressure from emerg brake when hot thru cool down? I'm doubtful but at this point I'm really confused as to what the heck is going on?

Help. :{

 

[B.G. Smith]

Drums

I would say yes, the E-brake could be causing the problem if you set it real hard with the drums hot. bg

 

[Extreme1]

Re: Drums

Originally posted by B. G. Smith

I would say yes, the E-brake could be causing the problem if you set it real hard with the drums hot. bg

They would need to be glowing. I've read here that a warped drum will keep warping as more heat is applied.



Are the fronts working right?

 

[Joe Mc]

Re: Re: Drums

Originally posted by Extreme1

Are the fronts working right?

Extreme1



Yes, just replaced the calipers, pads, pins and did all the lube stuff, made sure no burs etc. rotors were excellent. They're fine no pull etc. I replaced them as the front started to tug right again definite r/caliper not releasing - they're liftime so what the heck, right.



The hopping has been getting progressively worse and happens when slowing down, starts around 40mph and goes away under 15mph - depending on pedal pressure. More pressure less noticale. Nothing felt in the steering wheel, feels like the whole bed is hopping. Tried it using just the emergency brake and same thing only not as bad - only uses one shoe for emergency brake.



Thanks

 

[rattlnrench]

Joe,

I have a '99 also that was doing this too. I also found my front pads needing replacement @ 20k miles. There is a proportioning valve for the rear brakes mounted to the frame on the drivers side above the rear axle that I adjusted. It's a fairly simple procedure & might be worth a try. The valve works by measureing the height of the rear axle housing to sense the load you are carrying. What I did was to remove the actuator arm & reposition it to apply more rear brakes @ all times. There is an orange shield over the shaft of the valve that positions the shaft for installation. I could see where the shield was riveted to the valve @ one time. The first time the rear axle moves it breaks the rivet. I moved the position 1/8 " forward & it made a difference. No more hopping for mine. The shaft on mine does have play in it & I intend to replace the valve when I have time but I adjusted it for a quick experiment to see what it would do. The nut was a 7/16" if I remember right. You might check the shaft on yours to see if there's play in it. Don't know if this will help but I figured I'd throw it out there before you replace a lot of parts with no results. A side note is my brakes feel better now too.

 

[Joe Mc]

rattlnrench - thanks. questions: I don't AWABS ony rear your is same? and do you think adj of the rod is worth a try even though I feel same hop (reduced as emerg uses only 1 shoe) using emergency brake at speed?



Since you have a 99 and have been there I'd like to try what you are suggesting but, in past (2X's) the drums were out and required a cut to true up? I just "think" at this point (due to past two cuts) that the drums are too thin. I'll have the diameter checked first. Did you have the new drums checked for true prior to installing them? If so, did they require a dress cut?



Thanks

 

[rattlnrench]

Joe,

I only have rear abs. I only replaced the front pads recently but did the adjustment before that. I own & operate an independent repair shop & on a handfull of times seen rotors that were not cut true(haven't seen drums yet). I had a set of rotors on a nissan one time that were chucked up wrong when they were cut & were so bad the brake pedal almost went to the floor when I backed it out of the shop for a test drive. They were ruined. You need to check the remaining diameter of your drums to see if they can be salvaged. You also might be able to check the runout on your drums by mounting them backwards on the hub. Be carefull that there is not a lip on the drum that could cause you to bend it when you tighten up the lugs.

 

[rattlnrench]

Part 2... .....



Another possibility is a hot spot in the drum which may not be taken out with machining if its really bad. They are hard to see also. You might want to have them cut, if they are salvageable, while mounted to the bearing hub. It's possible the hole in the center of the drum is not true, that the drum actually indexes on the studs & that would throw the cut off. I always mark drums to hubs when I do brake work before I disassemble them just in case. The brake lathe may not be true either. If they were cut right the first time there shouldn't be a need for a second(they said they weren't true). Don't want to run out of space. PM me if you have any more questions or want to talk on the phone.

 

[GMIKEP]

Hippty Hoppity???

Try this site for info on a TSB currently under evaluation by Chrysler/Dodge.



http://www.dodgeram.org/tech/tsb/2000/xx-xx-00.htm



Bu** Sh** come to mind, but who knows. Note 2500 4X4 models only.

Hope this helps.

 

[dseabaugh]

how will body mount shims fix this shacking on braking??? sounds nuts to me. would like to fix the problem on my truck though as it is getting more regular

 

[Joe Mc]

GMIKEP - thanks. I don't know where they git this stuff from, go figure - DC never ceases to amaze me. Shim this and shimn that . . . it'll fix everything. Bunch of idiots. "Oh golly gee my light bulb keeps blowing out maybe I should shim it too. :

 

[Joe Mc]

Took another look at the TSB with out a number. Question - what thickness should the shims be? I guess that's in the more information to follow area.



:{ :{ :{ :{

 

[98rammer]

hoppin? i don't get any hopping unless under hard braking. besides the intermittant brake pull, i'm pretty happy with these brakes. i guess i'll keep my eye out.