Replacing a caliper on an older truck is half the job. The rubber brake lines get old and separate and can internally collapse. This will cause the caliper to hang up or not operate correctly. It could even burst! A safe rule of thumb is to replace brake hoses if you see cracks in the outer jacket or is 10 years old or more.

On the third generation Dodge Rams, there is a manifold of 5 lines and an attached hose. Three on top aone on the bottom left and one on the right side of the block. The flare nuts over time get a build up of grit and rust and jam on the line. The lines are safe, but they are hard to turn. This procedure can be used on any brake line.



Pretty scary looking Huh? It's easier than it looks except for dealing with the rust and scale in the flare nuts. This is what causes the lines to twist which is something you DO NOT want to do. Here's some easy steps to make your change easy. This will save those brake lines and the flare nuts for future service. If ever needed.




Tools



A 12MM X 10MM line wrench is a MUST! Don't even think of doing this without it. I strongly urge you use a high quality line wrench like an SK, Cornwell, Snap-On. The cheaper ones tend to stretch if you need to use some force. I used a Cornwell on this project.

10 X 12 MM Line Wrench
12MM Open end Box wrench
13MM Open end Box wrench (To remove caliper)
15MM Open end Box Wrench
18MM Open end Box Wrench
13MM Socket and ratchet (Extension)
Some sort of a torch with a sort of fine tip
Can of PB Blaster penetrating oil (WD-40 is junk)
Never Seize
Some grease for the end of the job.
GET NEW COPPER WASHERS FOR THE BANJO BOLT.
Never use vice grips unless the line is trash.

Try to plan your job in advance. Turn the wheel and start soaking the manifold with PB blaster a couple of days before. Spray the fittings as often as you can. This will give the penetrating oil time to work itself down into the nut. EXAMINE THE WHOLE BRAKE LINE TO BE SURE IT'S WORTH SAVING. Brake lines see between 3500 to 6000 PSI.

* Obviously you need to jack up the truck and remove the tire.
* Pick a flare nut and put the open end of the 12MM wrench on it to knock off some of the rust from the hex. Don't try to loosen it with the open end. Do this to all 5 flare nuts.
* Put the line wrench on each fitting and see which ones you can easily free up. Turn them slowly and watch the line to see if the nut is turning freely or it is twisting the lines. If the nuts turn free, spray them again.
* Below is a picture of the heating points. If the nut is stuck and you can loosen it. Spray it and leave it be for now. If the lines are turning with the nuts leave them be. They will need to be heated.


Red circles show heating areas. DO NOT HEAT THE BRAKE LINE DIRECTLY.
* When heating the fitting you need to be careful.
DO NOT HEAT THE LINE.
DO NOT TURN THE FITTING RED WITH HEAT.
Heat only the block and the flare nut in short intervals. If using a Hot Wrench 30 seconds with a cold flame is enough.
* Immediately try to turn that nut. If it spins free without twisting the line, spray it with PB Blaster. If not, spray it, let it sit, and go the the next.
Repeat this process on all the nuts. It may be necessary to hold the block with the 18MM wrench when trying to break the nuts loose.
* Once you have them all spinning on the lines. . . If they are tight, spray them and start working the nut back and forth with the 12MM open end. This will help you feel if the wrench is slipping on the hex or not. Every time you loosen, try to take an additional 1/4 turn. Keep spraying and working. It may be necessary to reheat the nut several times during this process. Just keep spraying and heating. Always keep the line wet.
* Once you are satisfied the nuts will spin, back them all the way out. Keep a careful eye on the brake line as you back the nut out.
Note: It's a real good idea you keep all the lines connected when heating. Brake fluid will spatter when heated with an open flame.
* Finally, back all the flare nuts out until completely unthreaded.
* Remove the two bolts holding the manifold and manipulate the manifold out. DO NOT BEND THE LINES.

TIP: Put some never seize on the flare nut threads. On the outside. If possible, get some on the back of the flare. This will eliminate this whole page if you need to go back in there.


* Reverse the process and gently start all the flare nuts making sure they are not cross threaded. Don't tighten them until you have started ALL the fittings first. If you pulled the block out right, they should start right back up. Run them in with the 12MM open end until snug and then finish the job with the 12MM Line wrench.

* Now you are ready to replace the hose on the caliper. Use the 15MM wrench to remove the Banjo bolt from the caliper. Put your new copper washers in. If you must reuse the washers, flip them over.

Bleed all the fitting except the hose fitting. That will be done at the caliper. Use the same process as you use on the caliper. Yes, you will get the air out.

TIP: Brush some grease on the lines and smear it over the nuts to prevent rust in the future. The oils from the grease will leach down onto the nuts and keep those lines forever.

Here is another good reason for replacing your hoses around 10 years.
If you look at the picture above, there is a chaff boot over the swage (SP) fitting. Water, road salt, dirt ect. builds up under that boot and rotts the swage away. Here is a perfect example. While the hose may have been OK, the fitting was a future point of failure.

Heed the warning.