Inherited a 2007 Ram 1500 4x4 SLT
Initially I had the Break, ABS, ESP/BAS, and the traction light on the dash lit.

Also when I drove the truck, slowly the breaks would begin to apply pressure to the point that on a 1/2 mile drive, it was real effort to get the truck back into the drive as there was a lot of pressure on the calipers. (All 4)

When I read the codes, There was 2 codes stating the LEFT FRONT wheel ABS SPEED Sensor was malfunctioning. (the live data showed that sensor was showing 427 mph not moving.

Replaced that sensor and the ABS light went out also the live data showed all sensors at 0 mph.

Still leaving the Break, ESP/BAS, and the traction light on the dash lit. and the calipers having pressure build up while driving making it impossible to drive after about a half mile.

I replaced 3 of the 4 calipers. I have all four just not time to replace 4th one yet.

I have bleed the breaks and also did a ABS Bleed on the breaks.

Another code showed up and it is a C121E "Break Pressure Sensor Comparative performance.

Okay last thing... I just noticed. When the breaks build up pressure while driving, I have noticed when I park, after about 5-8 minutes, you will hear a clicking or popping noise coming randomly from the calipers where it is loosing the pressure and going back to normal and after they stop releasing pressure, I can dive with no issues until the pressure builds back up.

I am stumped. I have bought all new hoses for each break and plan on putting them on, I have heard they can deteriorate and cause pressure in a caliper, but all four at once?

Appreciate any input and sorry so long... to much to make short.

 

Thanks, thought that was where I posted... sorry

 

You did. I wasn't paying close enough attention to where I was, but, when I went to move it, hhhmmm... It IS in the right spot. You just posted before I deleted my message.

Quickdraw!

 

Take a look at your brake hose. It could be contaminated, or pinched.

 

agree Bought all new hoses as its got a lot of miles... I was just wondering about all the hoses being bad at once... but I have been also thinking that it may be 3-4 things all adding up... old hoses, bad sensor (fixed) air in line (fixed) dragging caliper (3 out of 4 done)... sometimes stuff can get so neglected that you just have a lot of things to catch up with before you get it right...

 

I read your post more closely a second time. I agree that it's hard to imagine the same failure at all four brakes.
This may end up being an issue with the ABS or valves.
What's your brake setup, 4 wheel ABS? If so, that would be separate sensors for each front brake, and single sensor for the rear (aka RWAL).
Look up "isolation and dump" solenoid valves. You would have a set that is fed by each ABS sensor, total of 3 if you have 4 wheel ABS. One of the functions of these valves is to hold brake pressure.
YOu have done a lot of bleeding, and I would think that would clear out any debris that is restricting valve flow.
I don't think you will find many videos on ABS and valving, they just don't go bad often.
I recommend you continue with the new brake hoses, since you have them anyway.
How difficult was it to remove your calipers? and retract your pistons? Have you noticed ABS feeback recently when hard braking?

 

I had this problem when I Installed a new brake master cylinder and the rod that pushes the master piston in from the peddle had come out of place and was always pushing on the brakes. it was fine when I started driving but like you said.. after 1/2 miles the brakes would slowly get tighter until i stopped and gave it a rest......
Pull the master cylinder off . (don't have to disconnect the lines) get a flashlight and put the back part of the rod.. completely inside the round groove..then,, get something long to push the brake peddle in just a few inches (one side of rod on brake peddle one on your seat).. so the rod is sticking out enough to put it inside the master cylinder slot.. push the master back on the studs and bolt it back up by hand,, then tighten with ratchet... if you dont push the rod in a bit it will fall out again when installing....it will put some pressure on the master so you have to push in hard to get the nuts on by hand...
I am pretty sure this is your problem....

 

Boy that is interesting... never heard of that and want to figure out more about it... not sure what that means in reality... sounds like take master cyl off and reseat? suggestion would be helpful.

 

I Updated my post. its a 10 minute fix.