# All 4 brakes are dragging.



## chandler48 (Jun 5, 2017)

Disc brakes are constantly in touch with the rotor, so I'm not sure how much "drag" you have. I believe you also have a "brake in a hat" for parking brakes. They are normal drum brakes. Have you checked to see if they are too tight? Take those washers out from behind the master cylinder. They aren't doing you any good. It's all hydraulic.

Your booster may have too much vacuum on it (doubtful) but check it out anyway.


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## raylo32 (Nov 25, 2006)

I have seen this happen a couple of times. Especially in lightly used vehicles the issue is the pistons in the calipers develop a little corrosion line where they exit the caliper and/or the slider pins so don't properly float. As Chandler says they do not actively retract, they should float, and there is always some drag. But if you have corrosion on the pistons they don't move enough to release pressure on the rotors. You need to rebuild or replace all your brake hardware at the wheels. It isn't the master.


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## quatsch (Feb 4, 2021)

I had this once in one front wheel. 
The disk suddenly started heating, threw out bearing grease and steering was difficult.
It went away & I never found out what it was.


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## Fix'n it (Mar 12, 2012)

it used to be a thing where the hoses would fail on the inside. there would be a flap in there and would not release the pressure for a while causing the brake to not release.


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## Photobug (Jun 25, 2017)

chandler48 said:


> Disc brakes are constantly in touch with the rotor, so I'm not sure how much "drag" you have. I believe you also have a "brake in a hat" for parking brakes. They are normal drum brakes. Have you checked to see if they are too tight? Take those washers out from behind the master cylinder. They aren't doing you any good. It's all hydraulic.
> 
> Your booster may have too much vacuum on it (doubtful) but check it out anyway.


With the windows open I can hear the brakes dragging. Driving 5 miles had each rotor hot, so not just the parking brake.

How would I test the booster vacuum? I swapped out a new vacuum 12k miles ago. The vacuum on a diesel also controls power steering which seems less easy to steer than before.


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## Photobug (Jun 25, 2017)

raylo32 said:


> I have seen this happen a couple of times. Especially in lightly used vehicles the issue is the pistons in the calipers develop a little corrosion line where they exit the caliper and/or the slider pins so don't properly float. As Chandler says they do not actively retract, they should float, and there is always some drag. But if you have corrosion on the pistons they don't move enough to release pressure on the rotors. You need to rebuild or replace all your brake hardware at the wheels. It isn't the master.


All of the pistons are likely dragging. I think everything is a possibility but all 4 pistons getting corroded at the same time is less likely than i'd expect but being left unused maybe more likely.

The whole front brake system is relatively new. The back brakes are old but I have a full set of replacements ready to go, if I need to go there, but would like to test things before throwing expensive parts at an attempt to fix this.


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## Fix'n it (Mar 12, 2012)

you need to get all 4 tires off the ground. then have someone hold the brake while you stand at each tire. they let off and you see how soon the tires start to turn


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## chandler48 (Jun 5, 2017)

Photobug said:


> How would I test the booster vacuum? I swapped out a new vacuum 12k miles ago. The vacuum on a diesel also controls power steering which seems less easy to steer than before


Then I'd go with @raylo32 post #9 regarding the calipers. I drive a 3500 Cummins. The little blue canister next to the booster gives you one extra pump of pressure should the engine fail. The vacuum pump runs the 4wd axle, heat/AC blend doors, and brake booster. It doesn't have anything to do with the power steering as the power steering pump sits aft of the vacuum pump on the same drive. Remember a Cummins is a positive pressure engine with no natural vacuum, hence the vacuum pump.


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## Drachenfire (Jun 6, 2017)

raylo32 said:


> I have seen this happen a couple of times. Especially in lightly used vehicles the issue is the pistons in the calipers develop a little corrosion line where they exit the caliper and/or the slider pins so don't properly float. As Chandler says they do not actively retract, they should float, and there is always some drag. But if you have corrosion on the pistons they don't move enough to release pressure on the rotors. You need to rebuild or replace all your brake hardware at the wheels. It isn't the master.


I agree. 

The first thing I thought of reading the post was corrosion in the caliper pins and/or pistons.


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## raylo32 (Nov 25, 2006)

Yup, it does seem like a classic case, especially with the low miles. The only puzzling thing is if it really is all 4 at once as the OP says. I can't say that I have seen that before. But I have NEVER seen anything where a master or booster puts pressure into the brake lines to cause this sort of thing. I can't imagine how that would even work. But then my experience is limited to my vehicles and friends and family vehicles. Last case of this was my GF's once upon a time 2009 Camry. IIRC it was the rears that stuck and chewed all the way through the pads and rotors. Calipers were a mess and I just replaced everything. It also used to happen all the time to a motorcycle of mine that was parked outside under a cover and sat for long periods. I had to disassemble the calipers and polish off the corrosion buildup ring on the pistons every year or so.



Drachenfire said:


> I agree.
> 
> The first thing I thought of reading the post was corrosion in the caliper pins and/or pistons.


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## raylo32 (Nov 25, 2006)

Now I have heard of that, though I've never seen it. And it would be highly unlikely to hit all 4 at once.



Fix'n it said:


> it used to be a thing where the hoses would fail on the inside. there would be a flap in there and would not release the pressure for a while causing the brake to not release.


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## Drachenfire (Jun 6, 2017)

raylo32 said:


> Yup, it does seem like a classic case, especially with the low miles. The only puzzling thing is if it really is all 4 at once as the OP says.


I guess it would depend on how long the vehicle sat and the level of moisture it was exposed to in that time.

.


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## Fix'n it (Mar 12, 2012)

raylo32 said:


> Now I have heard of that, though I've never seen it. And it would be highly unlikely to hit all 4 at once.


it happened to me on one of my first cars, a Buick Apollo(ever heard of one of those, lol). and the F'n hose was expensive. and i have seen it a few times since

anyway. yes, very odd to be all 4. i have seen 2 hoses close to the master.

as i said, it has to be troubleshooted = all 4 off the ground, somebody holds the peddle down while someone tries to turn a tire = let off the brake and see what tires turn. those that do not, take the tire/s off. then do the same thing, but instead of turning a tire, you loosen the bleeder. wheel turns = hydraulic, if it doesn't = caliper. if hydraulic = loosen line fittings upline. do this until the problem is isolated.


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## Brainbucket (Mar 30, 2015)

You said that the booster also controls the steering. That is not a vacuum booster. That is a hydro-boost unit that is run by the power steering pump. That is probably your problem. I have seen that before. Hydro-boost starts applying pressure on the brakes.


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## raylo32 (Nov 25, 2006)

Interesting... how does this happen? Does it have a bad pressure regulator or maybe a check valve that is defective? Another thing that might be helpful is for the OP to use an IR thermometer on the rotors. "Hot" isn't a good measure and hard to tell differences by feel. Brakes are always "hot" to human sense of touch after driving and making even a few of easy stops.



Brainbucket said:


> You said that the booster also controls the steering. That is not a vacuum booster. That is a hydro-boost unit that is run by the power steering pump. That is probably your problem. I have seen that before. Hydro-boost starts applying pressure on the brakes.


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## Brainbucket (Mar 30, 2015)

I have no idea. Trucks brakes were applied and could not push truck by hand. Pulled master cylinder away from booster and could push truck. I guess the contaminated(old) fluid screwed up the internal function of booster.


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## Simransaini (Aug 19, 2021)

Brake dragging is commonly caused by broken or weak springs on the drum brakes. It can also be due to a corroded or jammed caliper piston or a caliper that has corroded bushings or mounting pins.


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## Mike Milam (Mar 3, 2017)

raylo32 said:


> I have seen this happen a couple of times. Especially in lightly used vehicles the issue is the pistons in the calipers develop a little corrosion line where they exit the caliper and/or the slider pins so don't properly float. As Chandler says they do not actively retract, they should float, and there is always some drag. But if you have corrosion on the pistons they don't move enough to release pressure on the rotors. You need to rebuild or replace all your brake hardware at the wheels. It isn't the master.


I just a couple months ago replaced 4 on my pickup for that very reason. Went to replace pads and rotors and the pistons were rusted and wouldn't go back in.


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## Photobug (Jun 25, 2017)

chandler48 said:


> Take those washers out from behind the master cylinder. They aren't doing you any good. It's all hydraulic.
> 
> Your booster may have too much vacuum on it (doubtful) but check it out anyway.


So I am trying to absorb all the different suggestions. It has been cold and rainy all week, finally got a break in the weather and have the front axle on a set of stands. The brakes drag but I can rotate the tires by hand but no free spin. The washers are still in there.

The thought behind the washers was if it is a hydraulic error causing the brake booster to be pushing just a little bit the washers gave it some space. I will remove the washers and see if that changes the amount the brakes drag.

How do I test the vacuum level?


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## chandler48 (Jun 5, 2017)

Messing with the booster and master is amounting to jousting at windmills. As the others have indicated, FIRST check the calipers for a rust ring preventing them from fully retracting. Your washer theory is not sound as the spacing of the booster is factory set and can't be modified for an error like what you describe. Besides, the booster will adjust itself automatically based on the vacuum provided. If your blend doors are working, and if 4wd is engaging (if you have 4wd), then the vacuum pump is doing its job.


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## Nealtw (Jun 22, 2017)

At 20 years old the flexible lines to the wheels are suspect. Open a bleeder, if nothing changes the problem is at the wheel.


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## iamrfixit (Jan 30, 2011)

Photobug said:


> So I am trying to absorb all the different suggestions. It has been cold and rainy all week, finally got a break in the weather and have the front axle on a set of stands. The brakes drag but I can rotate the tires by hand but no free spin. The washers are still in there.
> 
> The thought behind the washers was if it is a hydraulic error causing the brake booster to be pushing just a little bit the washers gave it some space. I will remove the washers and see if that changes the amount the brakes drag.
> 
> How do I test the vacuum level?


Your truck has hydro-boost. The power brakes are hydraulically powered by the power steering pump. You don't have a vacuum brake booster on this truck to test. 

Take the washers out and bolt up the master cylinder tight. Start the truck and see if rotating the wheel gets more difficult or if you are still able to rotate it. You're never really going to have the tires completely free wheel. The brakes will always offer some amount of drag so it's completely normal for them to be a little bit hard to rotate, especially as you initially try spin it. If it's 4x4 you'll also be spinning the front drive axle assembly. I would expect the tire to be a little hard to spin, but you should be able to spin it by hand.

You can loosen a caliper bleed screw to see if you get a squirt of fluid. A squirt of fluid coming out would indicate something is holding hydraulic pressure against the caliper. Could be a bad brake hose, kinked or clogged steel line, abs issue, as well as a master cylinder, booster, or pedal issue.

Besides something holding pressure, you could have caliper issues. This is really more likely than fluid pressure. The caliper assembly must be free to slide on the mount in order to be able to squeeze both pads evenly. If you have a sticking piston in the caliper that would cause both pads to drag. When the whole caliper assembly can't slide freely, this causes the outboard pad to either drag continuously or not be able to work at all. You'll also see an uneven wear of pads. If the truck sits around things like this can rust up and get stuck.

From there you'd need to remove the caliper assembly to make sure the wheel bearings/hub assembly is even free and able to spin easily.


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## turbo4 (Jan 30, 2021)

I have 2 sporadically used vehicles . Every time i use them i have to wear the rust off the rotors. The less i use them the worse it gets. Im sure eventually i will have your problem.


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## chandler48 (Jun 5, 2017)

iamrfixit said:


> Your truck has hydro-boost.


With a diesel that is correct. All you have on vacuum is 4wd axle actuator and blend doors. Sort of a dumb engineering feat to dedicate a pump to do just that. I have converted my 4wd to manual, leaving that big old pump to just change blend door positions.


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## iamrfixit (Jan 30, 2011)

chandler48 said:


> With a diesel that is correct. All you have on vacuum is 4wd axle actuator and blend doors. Sort of a dumb engineering feat to dedicate a pump to do just that. I have converted my 4wd to manual, leaving that big old pump to just change blend door positions.


Argh! Guess I misread his post #6

There are a few older gas engine trucks that used a hydro boost, although not the case with this generation of dodge.
Got an 89 F-super duty, cab chassis with a 460 that uses hydro-boost, put a rebuilt unit on it probably 15 years ago.


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## chandler48 (Jun 5, 2017)

Yikes, a 460. That's a gas station to gas station engine, what? 8 mpg or so? I had a 72, and was ever cognizant of the amount of fuel I had on board. I drive a 2001 Ram Cummins 5 speed 4wd flatbed dually, weigh in at 8000 lbs and still get 16 mpg.


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## iamrfixit (Jan 30, 2011)

Yeah, it may not even be that good, but it's got plenty of power. It's got a 14' dump box and is very local transportation. It's out of town adventures are limited to the quarry and the landfill.


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## Photobug (Jun 25, 2017)

chandler48 said:


> Yikes, a 460. That's a gas station to gas station engine, what? 8 mpg or so? I had a 72, and was ever cognizant of the amount of fuel I had on board. I drive a 2001 Ram Cummins 5 speed 4wd flatbed dually, weigh in at 8000 lbs and still get 16 mpg.


My backup vehicle is a 22 foot Class C. I get 8.8 MPG out of it when I drove it back this winter. When I drive it I can watch the fuel gauge move. It is why my truck not running has kept me a hostage at home this summer. My truck is closing in on 9000 lbs and I also get around 16 mpg.

Lets hope tomorrow is rain free so I can get in and do some more testing. One of the reasons I have trouble believe it is something at the wheel level is all 4 brakes failing is too much of a coincidence.


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## chandler48 (Jun 5, 2017)

Photobug said:


> all 4 brakes failing is too much of a coincidence.


Remember they are of the same age.

When I worked at ATL, we had one guy whose job was to rotationally change out fluorescent bulbs throughout the monster of a building. He changed them out regardless of whether they were burning or not. I asked him why, and he said they were the same age and if I didn't change them today, I'd have to come back tomorrow and change them.


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## Photobug (Jun 25, 2017)

I think I got it figured out. My front calipers which I thought were the ones replaced, turns out to be the ones I bought the truck with, possibly original. THey are frozen onto the rotors. I have put a clamp on them with the master cylinder cap off. I still can't get the calipers off. Any tricks to get the old frozen calipers off?


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## Fix'n it (Mar 12, 2012)

a large flat screwdriver and or a large prybar.


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## Photobug (Jun 25, 2017)

Fix'n it said:


> a large flat screwdriver and or a large prybar.


Already broke a pry bar attempting it. I will get after it with a pair of larger pry bars tomorrow.


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## iamrfixit (Jan 30, 2011)

Photobug said:


> I think I got it figured out. My front calipers which I thought were the ones replaced, turns out to be the ones I bought the truck with, possibly original. THey are frozen onto the rotors. I have put a clamp on them with the master cylinder cap off. I still can't get the calipers off. Any tricks to get the old frozen calipers off?


Loosen the bleeder screw, or loosen the brake line to make sure you don't have hydraulic pressure holding them. 

Find a pry bar or big screwdriver that will fit through the holes on the outside of the caliper and into the cooling fins of the rotor, or hook the edge of the rotor lip that sticks past the brake pads, then pry outward. You're trying to slide the caliper and at the same time push the piston(s) back in. If you can use a good sized pry bar, like a pointed sleever bar, you can apply a LOT of leverage.

Here's a video to help show what I mean


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## raylo32 (Nov 25, 2006)

Thinking extreme here... Maybe take a reciprocating saw or grinder with a cut wheel and cut the pistons off if you can get the tool in there. If all else fails take those tools and cut the caliper bodies in half and then hammer them off.


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## huesmann (Aug 18, 2011)

BFH.


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## Mike Milam (Mar 3, 2017)

Push come to shove cut the caliper where it crosses over the rotor. Cut off wheel or sawzall.


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