Removing trailer brake/bleeding brakes

[RSchanz]

I've replaced the front calipers and pads, new master cyl and new brake booster. Now the brakes need to be bled.

I've got a trailer brake that I don't use and I'd like to remove. Is it as simple as just disconnecting the brake line that goes to it and unplugging and caping the wires?

In terms of bleeding the brakes, I kept the old master cyl top in order to make one of these at home bleeder add on things seen on this write up. I guess due to the metering valve this entire process is a bit more of a PITA than it should be? Is this linked write up overkill, is there an easier way to go about this where I don't need to attached an adapter on the old master cyl top?

 

[IDIBOBS]

Wow. So first, you still have an old hydraulic trailer brake controller? I thought those went out in the 70s. A picture would help with telling us how it is plumbed into the system but in general yes you should be able to just cap the line and remove.

On the bleeding the brakes. I have never messed with any of that stuff and I build trucks from the 40s - 2000s.

I just have one guy (me) sit in the drivers seat and a second guy ( proby, kid, young guy) go under the truck. I press the brake 3-4 times to build pressure, hold to floor, then they open and close the bleeder. Do that untill clean new fluid comes out and no bubbles. Start in the back right, then back left, front right and front left. And repeat if needed.
Make sure drum shoes are adjusted before you start. It has worked on every vehicle ever touched.

 

[RSchanz]

^^ This is what I've always done but according to this write up the metering valve screws everything up and its easier this way. I think I'll just bench bleed the master then try the old fashioned way first.

I think I'll be able to just pull the whole line out of the system, its got some splitter coming off the master and then it's pushed through the firewall. It won't let me upload an image right now for some reason but imagine this... red wire, blue wire, black wire running into the back and then of course the hydraulic line.

 

[IDIBRONCO]

If there's a splitter right off of the master cylinder, you might be able to remove the splitter and hook the brake line that goes out from it back to the master cylinder. No plugs needed.

 

[IDIBOBS]

If there's a splitter right off of the master cylinder, you might be able to remove the splitter and hook the brake line that goes out from it back to the master cylinder. No plugs needed.

Yup this. That’s why was hoping for a. Picture. I’ve seen a few different ways they used to run those. I’d bet this is very doable.

 

[RSchanz]

If there's a splitter right off of the master cylinder, you might be able to remove the splitter and hook the brake line that goes out from it back to the master cylinder. No plugs needed.

Yes, on the master there is just a splitter so I can plug the brake line right back on there. I'm more curious about the wiring. Would just unplugging it and then capping the wires off be ok? Picture below:

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[IDIBRONCO]

Would just unplugging it and then capping the wires off be ok?

It should be. I removed the non working brake controller in my Blue Truck years ago. I just cut and covered the wires. It was completely electronic, but wires are wires in my opinion.

 

[RSchanz]

It should be. I removed the non working brake controller in my Blue Truck years ago. I just cut and covered the wires. It was completely electronic, but wires are wires in my opinion.

Yeah that makes sense. I'll report back after completion.

Any idea what that blue wire thats unplugged with the spade is?

 

[IDIBOBS]

Yeah that makes sense. I'll report back after completion.

Any idea what that blue wire thats unplugged with the spade is?

Sounds like you’re in the right track. As for the blue wire it’s not stock so who knows. My specialty is wiring. I hate junky after market/home done bad wiring. I’d trace it as well as the brake controller wiring and try to remove it from the source.

 

[franklin2]

Blue is the standard color for the trailer brakes. See if that blue wire runs back along the frame to the rear bumper area.

As far as the proportioning valve hurting your ability to bleed, I have never on any of these trucks ever had that problem.

 

[IDIBOBS]

Blue is the standard color for the trailer brakes. See if that blue wire runs back along the frame to the rear bumper area.

As far as the proportioning valve hurting your ability to bleed, I have never on any of these trucks ever had that problem.

Kinda already established that it’s not electronic trailer brakes so there would not be a blue wire to avtivate the trailer brakes from a hydraulic system. It this point with the age of the truck and how previous owners may have messed with the wiring who knows what has been done to it with out tracing wires. First thing I do to any older vehicle I get is to rip out all the old junky after market wiring.

 

[IDIBRONCO]

Any idea what that blue wire thats unplugged with the spade is?

Kinda already established that it’s not electronic trailer brakes so there would not be a blue wire to avtivate the trailer brakes from a hydraulic system.

???

 

[Black dawg]

Have next to no experience with those old school hydraulic/electric controllers, but yes, just take however that line is adapted into the line at the master out. Controller looks like maybe it has a power and a ground, and then the blue output wire that puts out amperage to run the electric trailer brakes. I would remove the power and ground wires from the truck, but save the blue wire for future controller install.

Why is the fuse box just hanging there?

 

[Black dawg]

???

Lol.

 

[franklin2]

Kinda already established that it’s not electronic trailer brakes so there would not be a blue wire to avtivate the trailer brakes from a hydraulic system. It this point with the age of the truck and how previous owners may have messed with the wiring who knows what has been done to it with out tracing wires. First thing I do to any older vehicle I get is to rip out all the old junky after market wiring.

It is a brake controller. It is controlling electric brakes on trailers. The wire to the rear, whatever color they used, leaves the brake controller and runs along the frame to the trailer plug to supply the electric brakes on the trailer.

They had their act together in the old days with these old controllers. The only problem with them, they were some work to tie them into the hydraulic system.

What is the hurdle that everyone tries to cross with a brake controller? Proportional braking. You have all these aftermarket controllers with little pendulums inside that have to be mounted level, or some sort of electronic gravity sensor. Or you have the new Fords with the integrated controller tied electronically into the braking system.

What did these old brake controllers do? Proportional braking by tying directly into the hydraulics of the brakes. They worked well. They were simple. The hydraulic pressure would apply pressure and move a large variable slide resistor that varied the voltage to the trailer. All you had to do was get it setup in the ballpark to your particular trailer, and it just worked.