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okay so heres the deal ive got a 94 CTD 4x4 auto that has a really strange problem with the back brakes. ive had to change them 3 times since last feb. shoes and drum all 3 times. first time i did it myself the last two times its been to 2 different garages, ive changed everything. portion valve, brake cylinders yada yada everything that has to do with my rear brakes has been changed. i tried backing them off all the way so they wouldnt touch the drum and they are still wearing out and getting so hot it warps the drums :S: im stummped guys
 

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Perhaps your outer axle bearings are shot allowing wobble.
 

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Have you tried changing the rubber line between chasis and rear axle? They can break down over time and cause the brakes to not release properly just as they can on front, except on front it will cause one wheel to drag and cause steering wheel to pull to one side. Also, have you checked to make sure front brakes are working properly? Master cylinder could be putting all pressure to rear shoes and none or very little to front calipers. Something else that comes to mind is a kinked or partially kinked front steel line between proportioning valve and tee where the two lines separate going to each front wheel.
 

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did u rebuild brake cylinders
 

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UPDATE:

Heres the exact problem: What is happening is the brake shoes in the drum are becoming unadjusted and expanding, locking up the rear brakes over the course of a kilometer or two. You can readjust them by reversing with the parking brake on, or with the inspection window in the bottom of the back of the drums or by taking the tire and drum off. No matter what, they ALWAYS lock back up within a kilometer. And I mean lock up. Within that kilometer what happens is when you press the brake 100% for instance, the back brakes will lock up. You drive for another little bit, they will lock up at with the pedal at 75% and so on and so fourth.

Knowing this I went over the brake system with 2 class A mechanics and an apprentice today for about 4 hours. We looked at everything and came up with this:

- The brake cylinders havent been touched as far as we can tell, but we also know that they could be off a 1 ton setup, not the 3/4 ton its supposed to be
- The adjusters are on the proper sides, but the brake shoes were reversed (they were on the wrong sides, short was on the back) We thought we had it fixed but we came up with another problem (more on this later)
- Could be the flex hose, but there was no kinks or knicks in it at all
- Brake booster could be frigged (were going to test this more on Monday at the shop)

So once we changed around the back shoes, the truck stopped fine and worked great for about 5 or 6 kilometers then the same problems started happening again. AT about this time (after putting on roughly 60 test kms on today) we started feeling a klunk under the truck, and low and behold the drive shaft started to warp, and now its banging off the gas tank when it spins. The U-Joints feel tight, so knowing all this we're thinking the rear axle was rotating up over time causing vibration in the axle (even though we couldnt feel much of a vibration when we were driving it) which in turn translated to the back brake drums causing the adjusters to become unadjusted, along the lines of what illflem said up above. Saying that, the axle bearings and seals were changed less then a year ago.

So bottom line we are stumped. Were taking it in on Monday to the shop to pinpoint the problem and hopefully fix it. What Im asking for again is if anyone has another idea what could be causing my problems knowing what I just found out today, just to point us in the right direction for monday.

Thanks Jordan
 

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Jordan I'm about 45 minutes from you,I could come and look at it Sunday and give you some ideas and I am interested because it's an odd problem to have since the rear brakes on these trucks don't work well.You can PM me if you'd like me to have a look.
 
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what a beautiful mess!!
i go with a bad line and the brakes may be causing driveline jump-roping not the other way around. meaning the driveline causing the brake problem.

the adjusters seem to be operating in reverse no matter that you say they are properly installed.
its just too many variables and you mention an axle bearing? what ?
lets get the terms right so we can know just exactly what you mean driveline warping?
i am not being much more of an than i usually am but you are confusing us with your descriptions first you say you have changed the wheel cylinders and then you say later they "havent been touched as far as we can tell" i am more and more impressed with RPegram's posts every time i read them best start with his ideas
check carefully that you have indeed got the adjuster thing right drums on right and tight wheel hub bearings are tight and they need to be Tight! and the pre load is adjusted properly
and get an ASE certified dodge mechanic if yur gonna spend money on a shop.



i
 

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what a beautiful mess!!
i go with a bad line and the brakes may be causing driveline jump-roping not the other way around. meaning the driveline causing the brake problem.

the adjusters seem to be operating in reverse no matter that you say they are properly installed.
its just too many variables and you mention an axle bearing? what ?
lets get the terms right so we can know just exactly what you mean driveline warping?
i am not being much more of an than i usually am but you are confusing us with your descriptions first you say you have changed the wheel cylinders and then you say later they "havent been touched as far as we can tell" i am more and more impressed with RPegram's posts every time i read them best start with his ideas
check carefully that you have indeed got the adjuster thing right drums on right and tight wheel hub bearings are tight and they need to be Tight! and the pre load is adjusted properly
and get an ASE certified dodge mechanic if yur gonna spend money on a shop.
i
I was told the brake cylinders have been replaced but when we had the drum off we could tell it wasnt changed.

And the only reason I mentioned an axle bearing is because another poster up there did, so Im trying to reduce the variables.
 

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I think your problem either lies in your E-brake adjusted incorrectly or even slightly siezes cables, or your auto adjusters are not working correctly.

A quick test to see if your brake hose is not allowing fluid to return is to apply the brakes with the wheels in the air, release the brakes and see how quickly they release. (I really doubt this is it)

The emergency brake arms must be in a neutral position when they are released, meaning the bar that goes between the 2 brake shoes has to be able to move side to side slightly. The brakes on your truck are called a "dual servo self energizing" system and if the e-brake is not working correctly your brakes will essentially self energize. This is a very common and often overlooked issue. It must be checked with the brakes adjusted correctly as well.

To verify the auto adjusters are in the "right" way, just make sure that the threaded (bolt) portion is away from the shoe with the adjusment arm on it...

If the adjusters are on the wrong side of the truck, they will back your brakes off as you drive, which is not your issue.....

If you cant figure it out, post pictures! Alot of people on here know there stuff and will likely see the problem......
 

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One more thought.. It is possible to install wheel cylinders from a chevy one ton in the dodge 3/4 and one tons and this may have been done to yours. They will look right at home as they bolt right in, but are a larger diamater than the stock (correct) ones.
 

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I think your problem either lies in your E-brake adjusted incorrectly or even slightly siezes cables, or your auto adjusters are not working correctly.

A quick test to see if your brake hose is not allowing fluid to return is to apply the brakes with the wheels in the air, release the brakes and see how quickly they release. (I really doubt this is it)

The emergency brake arms must be in a neutral position when they are released, meaning the bar that goes between the 2 brake shoes has to be able to move side to side slightly. The brakes on your truck are called a "dual servo self energizing" system and if the e-brake is not working correctly your brakes will essentially self energize. This is a very common and often overlooked issue. It must be checked with the brakes adjusted correctly as well.

To verify the auto adjusters are in the "right" way, just make sure that the threaded (bolt) portion is away from the shoe with the adjusment arm on it...

If the adjusters are on the wrong side of the truck, they will back your brakes off as you drive, which is not your issue.....

If you cant figure it out, post pictures! Alot of people on here know there stuff and will likely see the problem......
We did the brake hose check with the truck up in the air and it snapped back to where it should be in no time. That was the part that worked great.
 

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UPDATE:

We think we got her figured out; its gota be the rear flex hose. Thats going to be installed tomorow along with a new pinion seal and U-Joints.

I also cant thank 12vFan enough. He drove 45 minutes to my house today to help me fix my truck and when we got it fixed I offered him money and he wouldnt take it. 12vFan wouldnt even refused my offer when I offered to cover his diesel cost to get to my house. Honestly Cummins Forum has some of the best guys around, willing to help you out. Thanks again guys!:thumbsup:
 

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Your welcome Jordan.Let us know when you get the parts changed if everythings good.
 

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Interesting post, I am going through the same type of issue but with the front brakes. I'm warping rotors in under 10K KMs(6K miles) Back to the shop tonight, may call the mechanic to see if it could be a front flex, as I have replaced the Calipers, Rotors (twice under warranty) and the pads. Calipers have been serviced and aren't sticking, but wondering if they are hanging up long enough to create excess heat. I have a lot of brake pad dust buildup on the rims right now. All highway miles, no towing and never stomp on the brakes as I keep it at a reasonable 100kmh (60 mph).

Will see what my mechanic finds Tuesday.
 

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Great thread, and THANK YOU for coming back and writing what you have found.

It really helps to have this info here written down.

I put my $2 (hey, inflation) as RPegram said, with the rear flex hose.
They can "collapse" inside, holding all the pressure on the other side (ie, drum brakes stuck "expanded").

Let us know how it goes! :)
 

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Interesting post, I am going through the same type of issue but with the front brakes. I'm warping rotors in under 10K KMs(6K miles) Back to the shop tonight, may call the mechanic to see if it could be a front flex, as I have replaced the Calipers, Rotors (twice under warranty) and the pads. Calipers have been serviced and aren't sticking, but wondering if they are hanging up long enough to create excess heat. I have a lot of brake pad dust buildup on the rims right now. All highway miles, no towing and never stomp on the brakes as I keep it at a reasonable 100kmh (60 mph).

Will see what my mechanic finds Tuesday.
this is common on my trucks that see a lot of heavy use.
check bearings that allow the wheel to run out of line check your center nut on the axle too.
could be the caliper or the the brake hose lining deteriorating which will not let the fluid return properly
 

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Just a follow up, had the calipers and flex hoses changed today just so I'm not wasting any time replacing 1 part at a time as I need the truck on the road. Braking feels much better, and not grabby as they were before. He turned the rotors as they had a little bit of chatter.

Hope this is the end for sometime, budget for any mods keeps getting spent on daily wear and tear items LOL.
 

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the nature of some used vehicles....
 

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If your lines née to be replaced make sure you go with mopar or the original because I use aftermarket and
there was one little thing different and it
caused my front brakes to not be releasing the caliper.... Lol so make sure the parts are exact
 
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