Archived Brake Problem

[Joe Mc]

Sorry for the long post - this involves a two week battle with the rear brakes on my beloved CTD. And of course we're leaving Thursday for two weeks of family fun and 6k of road to and from the Grand Canyon. We're taking the truck - I mean the family car (wife's Miata is way to small for the three of us and all the camp gear etc. ) Won't drive no stinking Mini van (In-Laws auto)



You may have seen my post from two weeks ago on the 2nd gen non-engine forum titled "hippity hoppity rear when braking". If not - when braking between 40 & 10mph (or so) the back of the truck bounces, not real bad but enough to be annoying. Put the emergency on at the same speed and get the same results. Simple right diagnoses as out of round drums- NOT. Check this link out it pertains to the exact problem - You'll love the typical DC fix "shim this and shim that, shims will fix everything baby". Just like the 3. 5mm one that came off my r/front, was their fix for brake pull. The shim is proudly displayed hanging from a nail on my garage wall for the past 5k of smooth braking, of course up till the rear end started to test my affection for my beloved Cummins/PARTS MONSTER/MONEY PIT. sorry

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



Anyway, here's where I'm at now (a bit calmer than yesterday when I lost my first attempt to post a 911 due to too many smiles) I took off the original close to 100k drums, which were cut 2X's prior (due to same hop deal), measured them at just over the 332. 5mm. So for $86 X 2 I put new ones on (Wagners) same hop. I disconnected the RWABS connection same thing, disconnected the height sensing proportioning valve rod (wire tied the lever in a stable position for testing) same thing. I didn't set the brakes too tight either just tight enough so the drums could easily slide on with no interference from the shoes. I let the auto adjusters do their job. Incredibly the RWABS & auto adjusters work on mine.



Is the lever on the proportioning valve supposed to be free when you remove the rod (no tension either way?) I thought it would at least spring to a neutral position (might be the problem? not sure). Every time I stop now I smell brakes from the rear, shoes & drums getting used to each other?



Am I missing something that's so simple here because I'm looking to hard at it & in the wrong area? Only thing I haven't tried is flushing the brake system. I'm getting weak here and really need help on this one and soon.



I've seen other posts in the past describing similar situations and thought to myself thank god mine doesn't do that and sounds like out of round drums to me. I just can't accept another statement "all trucks 3/4 ton and up do that". Why did mine just start doing it then?



Guys I'm pleading with you here - the wifey is starting to get upset too. She's liable to tell me to trade it in - of course on something she would have to approve of LIKE A FRIGGIN FRD or CHEBY. I DON'T WANT TO DRIVE NO DARN WANABE A REAL TRUCK!

Help me, heellllppp meeeeee!:{

 

[illflem]

How are your shocks?

 

[B.G. Smith]

Brakes

Can you disconnect the rod on the proportioning valve completely and try the brakes with out it? bg

 

[BK]

I went to the tsb link you posted... I don't get it. It sounds like the feel good tsb for the front wheel shims for brake pull, which just doesnt make sense given all the other physical properties in play with the front end.



At 100K miles... . I would replace all the hardware in the rear drums. . all the springs and retainers. They do wear out from heat and loose their properties. The rear shoes could be trying to rotate inside the drum as they grab.



I would agree with checking the shocks.



I have a 99 QC 4x4 with an 8' box. I dont have this problem.



Maybe the rear leaf springs are tired and at the low speeds your getting some axle twist when the brakes are being applied.

I would have someone drive next to me while trying to induce the problem. If it's spring wrap, it should be noticable. (why not at the higher speeds?... more of the weight is being transfer to the front brakes during harder quicker stops. . during slower less aggresive stops from higher speeds, your not appling the brakes as hard - the rears arent grabing as much... , but @ 10 - 40mph - more around town speeds we tend to stop on a time, on/off style,,, all just some thoughts).



I havent played with the rear level sensing rod for the brakes on my ram. . but on my othet trucks that had it it swung free when not attached to the axle.



What color is your brake fluid?

But you do say they rear brakes seem to be working well... . so I doubt it's the fluid. The fronts usually show signs of the fluid being bad by showing brake fad or loss of pedal from too much water in the system.



Does your accumulator pass the test? start the truck, check the feel of the pedal. Turn off the truck, you should have 3 or soo depressions of the pedal before you loose the pedal.

If you search the board for this, there were some good threads that talked about this test. . incase I dont have it correct.



With all this mileage allready (100K on a 99) sounds like you do a lot of towing? Gives me more thoughts to the rear springs if it's not the rear brake shoe's hardware.



Oh, other thought. . binding in drive line. . checked your rear UJ's and carrier bearing lately?



Let us know what you find. .



Bob

 

[Joe Mc]

ilflem - The shocks are not original - Monroe's (spelling) I think Magnums, they were on it when purchased 25k ago for who knows how long. They show no signs of fluid leak and take the bumps well. Will have to consider once I do the follow and watch as BK suggests.



B. G. Smith - On the height senstitive proportioning valve - I totally removed the rod, placed it in the middle of its 180* throw and wire tied it so it would not move for the test. Same results.



BK - Yea the TSB is very simlar to the shim the front wheel cure for brake pull BS eh? Great idea w/the brake hardware thought - never thought the shoes might be trying to spin w/the drum and then releasing and stretching and so forth - This to me sounds to make most sence so far. The shocks are a good thought too. Also who knows what the previous owner did? I know he was a contractor as evidenced by the pea gravel in the bed when I first saw it before the dealer had chance to prep it. Since he was a contractor and the truck has an elec. trailer brake he may have towed a backhoe for 75k miles for all I know? As far as me I haven't towed a thing since I bought it (about 25k ago and 13 months) I run mostly empty and on occasion a few hundred # max in bed. U joints & carrier checked OK Saturday morning. Accumilator is fine. I'm thinking of flushing the brake fluid just for giggles who knows maybe there's an air bubble somewhere? I bled the front when the new calipers went on about 4-5 weeks ago . . . (huumm) funny the hopping started about a week or so afterwards.



I'm going for the brake fluid flush, then the hardware (should have changed it when I did the shoes last June - infamous axel seal leak) then the shocks. The big decision, of course, is what kind of shocks - will do a search to match my style of driving.



Thanks everyone I'm feeling better already.

 

[Hammer]

One thing I'll ask joe is have you replaced the rear shoes at all??,,Or do you know what shoes are on it right now??,,Reason I ask is this,some linings for the rear of our beloved Rams are weather sensitive,sounds stupid(did to me too)but I do believe it,,Now I know out here we have been having a rash of heavy rain storms and high humidity,some companies shoes are able to absorb this added moisture and cause this problem(NAPA's are the worst for this),,Does your truck have the uypgraded rear wheel cylinders(1 1/16 ")??,,This will help with some rear braking problems,,Make a call out west Monday morning to TDR brake guru Sam Peterson,its worth your while he should be able to put you on the proper path,,His number is(360)357-4958... . Hours are 8:30 am to 5:30 pm Pacfic time,,Let me know if you do not get it fixed will be on vacation from the 5th to the 15th and I could give you a hand if you need it... ... . Andy

 

[Joe Mc]

Hammer - replaced the rear shoes with Wagner's back in about June/July last year due to the infamous r/axel seal leak. That was about 20k ago. Not sure if it has the upgraded cyl's or not, I haven't installed them . . . yet.



Thanks for Sam's number I'll call him Monday. Have a good vacation Andy and I'll have a better one myself once I get this blasted brake problem taken care of.



I've been wondering about the suggestion of changing the brake hardware - aren't the springs main function to return the wheel cyl pistons and hold the shoes to the brake plate?

 

[EricBu12]

Joe,

yes the springs main function is to return them and they most likely do od yours but as the other guy said, they get weak and cause them to shift. there is 2 coil springs on the shoes to hold them to the backing plate. If they are weak, then they could shift over. also there is a spring for the emergency brake and 2 big springs for the return of the shoes. any or all of these things can have a factor on it.

The weak leaf springs and shocks are an interresting therory. I have Rancho RSX shocks. they have a valve inside them that automatically adjust the dampening to changing road conditions. I love them and I have the old shocks for spares but I am wondering why, the Ranchos are that good...

I have a 01 and I have had it since new and have not had your problem but I don't have the miles you do either. I would bet to just replace hardware, shocks, flush fluid, and see what happens.

Hope you have a good trip and I hope you figure this out.

Eric

 

[Extreme1]

A couple things come to mind...



1) New hardware probably won't fix it but it can't hurt. While you're in there, be sure and clean (sand) the points that the edges of the shoes contact the backing plate. Then put a THIN smear of high temp grease on the cleaned spots.



2) Springs and shocks - very doubtful the cause but a new pair (or set) of shocks can't hurt and might make it ride better. Unless the springs are broken (they usually fail near the center when overloaded), they should be OK. Usually one side will have more leaves broken than the other and the truck will lean to the side with the broken springs.



3) Load sensing/spring loaded porportioning valve - never liked them. I usually tie them to keep them from moving and adjust my driving (my 3500 doesn't have one). Try tieing the lever (or rod) at each extreme to see if it makes a difference.



4) Bear in mind how drum brakes work - the shoes have to rotate slightly with the drum in order to function and self adjust. Adjust them up until they rub and back off until they barely don't. Apply the brakes a few times to center the shoes.



5) Flushing the fluid might have an affect. Many times flushing a system will stir up all kinds of crud that catches on the edges of ports or under seals and causes temporary or intermittant problems.



6) Try these fixes 1 at a time and test drive in between to evaluate the results. Please post the results.



7) Having someone else drive the truck with it exhibiting the problem is the best diagnostic tool. As mentioned above, look for spring wrap, verticle movement or other things oscillating in the suspension. Verify tire pressures and runout. Don't be afraid to look at the front either. Good luck.



Can any one explain why shimming up the front body work would help a brake pull?

 

[Larry Willard]

Looks like most everything I would have thought of has been covered, if all else fails check the tires for out of round. I had a similar problem a few years back and found the tires by jacking up the wheels and spinning them with a block of wood against the tread. One tire had a high spot and one a low spot, tires were replaced and braking was then smooth.

Larry

 

[Joe Mc]

Update/Finished

Spoke with Sam Peterson - really knows his stuff and easy to understand what he's talking about. Short story is the drums were thin cause I had to cut them cause I had the brakes set too tight:{ A prime example of learn from your mistakes. So they became warped. Installed new drums w/old shoes. Sam explained heel & toe of shoe doing the stopping in new drums and bouncing around in the drum, as they wore to the old larger diameter (cuz they were cut). So installed new shoes, brake hardware & had drums trued up. It's as good as it's going to get. Pretty smooth after less than 20 miles. Finally! I'm happy.



So the moral of the story is for those folks that are used to setting car brakes don't set them too tight. What is too tight/how should they be adjusted. I'll try to relay what Sam explained - turn the adj star wheel till the wheel is difficult to turn, apply the brake pedal then back off the star wheel till there isn't any drag. If you count the points as you back off the star wheel you should try the same amount when you do the other side. This is what I understood Sam to say. I really hope I'm not wrong$$$$$$



Thanks for everyones suggestions.

 

[BK]

glad to hear you got it all fixed and found the real solution.

thanks for sharing... so we all know.



This wasnt the 1st time I've seen this problem posted on the board, but don't remember seeing a post decribing the fix.



-bob

 

[Hammer]

Joe Mc,,Glad to hear Sam got you fixed up,,His brake knowledge is a great asset to our boards and has helped me in the past also,,See Ya soon... ... Andy

 

[Joe Mc]

Spoke too soon

In Morristown, TN Days Inn Lobby using their Guest PC. We traveled 550 miles today. It still doe the hippity hop, it but not so bad. I'm suspecting the tires, Coopers. Also not noticed before there seems as if there is a comes & goes vibration, hard to tell for sure but from the drivers seat seems as it's from the r/rear. It gets more pronounced between 55 and 75 then it sort of goes away after 80 or so. Tires out of round, broken band out of balance???? All possible. Does this sound like the shaft carrier bearing??? As luck would have it I took a wrong turn and came upon a Cooper Tire Center Oo. closed (7/4) I'll pay them a vist tomorrow and have them inspect the tires, we'll see what happens next PC I come upon I'll update. It's late and gotta get some shut eye. LAter on.

 

[BK]

out of round tires, you would almost allways feel. .



Sounds as if they are out of balance, since you have a window of vibration. how long have those tires been on?

 

[Hammer]

Remember also Joe,your truck is still one of the ones with the infamous wheel problems(steel chrome directionals),,they had big problems with those wheels until 2000 when they went to the aluminum set,,They are noted for being out of round and not being able to accept loads well(kinda a wishy washy feeling when towing),,Have the balance checked and you'll also see if the wheels are out of round,,Also make sure the shop torques the wheels back on and does not run them on with a air gun,,One other thing to consider,especially with this heat,is the load rating of the tires you put on(if I remember correctly they were D),,A lighter rated tire with lower pressures(lower than the E range) will build heat faster and have that sway feeling,,Depending on how fast you ran and the temps outside I have seen a lighter rated tire on these trucks actually separate the belts which will cause some of the problems your experiencing,,hope you get it figured out..... Andy

 

[TWeir]

I have to agree with Hammer about the steel chrome rims. I had similar problems untill I changed to after market rims. When I would rotate the tires I would have problems untill I would rotate then back again and then it would get better.

Fingers X, I have not had any problems sense I put on new rims.