Trailer Brake Controller Help.

[Soundguy]

Maybe it was because an improper splice in the brake line for the pressure sensor could cause all your braking to fail including your trailer brakes. If they didnt sense any pressure due to the tee splice blowing, they also wouldnt work would they? Personally I wouldnt want to put a splice in my trucks brake lines. If you can fly an fighter plane with nothing but wire connections to servos, then they should be able to make a simple electric braking device to sense decelleration and apply an ample amount of voltage to the brakes.

There are some good inertial, and timed systems.... I like them better than a connection into a wet line..

soundguy

 

[Soundguy]

Loosing all brakes would not happen. I can not think of a single truck I have ever owned without a dual chamber master cylinder.

Chris

you can run all the oil out of your resv if it keeps trying to pump it out the back blown line / brake seals.. etc..

soundguy

 

[jlrsn]

Actually what Chris said was right. By the design of the Master Cylinders and Brake Systems made mandatory in all cars sold in the U.S. since 1968, even though you see one Master Cylinder it comprises of two separate brake circuits, each with its own fluid reservoir. If a line is broken in one you will still have one operational brake system to at least two wheels. I know that is true with cars but I don't know when it became mandatory in trucks.
Jim

 

[Soundguy]

it's still not ideal, one set of brakes on a moving rig w/ trailer and a load....

does the unit that taps break pressure tap both circuits? or one? if both.. you have the possibility of no braking at all.. if one.. and that is the dead circuit.. then still only one circuit.

at least with the e-brakes you can reach down and grab the panic switch to control a situation like a sway.. etc.

soundguy

 

[Newblue]

it's still not ideal, one set of brakes on a moving rig w/ trailer and a load....

does the unit that taps break pressure tap both circuits? or one? if both.. you have the possibility of no braking at all.. if one.. and that is the dead circuit.. then still only one circuit.

at least with the e-brakes you can reach down and grab the panic switch to control a situation like a sway.. etc.

soundguy

http://i287.photobucket.com/albums/ll150/Newblue2008/DSC00222.jpg
Red button on the side will activate the trailer brakes. Only one circuit is used for the transducer.

 

[Diamondpilot]

You guys worry too much. Drive behind one and you will be sold. I still say its the second best thing on the market behind the Ford Factory unit.

Chris

 

[Reg]

Thanks Reg. Good points. Kenny, it probably did have the Torflex suspension. I was looking for brake wires etc and when I saw no leaf springs I assumed there was nothing there. Seemed crazy, but I don't know much about trailers in general and even less about horse trailers.

I'm not sure what this trailer is made of. Top and sides look aluminum. Frame is definitely not aluminum. Trailer looks to be about 10 years old. Doesn't look new but is in good shape.

It could be aluminum skin over a steel frame.
The top half, say from about 4ft and up is built very light on most horse trailers.
Horses CAN kick that high, but generally don't, so builders go for weight savings higher up.
Run a magnet around it, tap to find the "studs"(pun).
If the magnet likes the studs, but not the skin then you have aluminum over steel.
Fiberglass roofs are also common and there MAY be some with a whole fiberglass top half.

Re dual brake hydraulic circuits;
I liked the Volvo diual circuit in their pre-Ford days.
One rear wheel and both front wheels on one circuit, the other rear wheel and both front wheels on the other.

....and BTW, you COULD tap into both circuits on a modern truck.
It would take a couple of one way valves and two clever returns, but it COULD be done.

 

[mojoinco]

I've used a number of trucks over the years with brake controllers that tapped into the brake circuit (generally the rear if I remember correctly) and never a leak, nor have I ever heard of one leaking (undoubtedly it has occurred). The first sign would be a wet spot on your shoes or the floor mat. There are a lot of areas to fail before worrying about this happening -- like folks replacing the brake fluid occasionally (anything darker than a very light ylw/tan is bad; some would say that is even too much). Or replacing the cracked flexible lines to each front wheel, the rear axle, and the other one if you have a front drive axle.

Light duty trucks had to go the dual brake circuit route at the same time as cars did (as well as have back up lights, windshield washers, side marker lights, etc).

Had a 240 Volvo. That dual circuit system was a royal pain if it wasn't bled correctly (there was a very specific process or you would be there all day). Great design, others use it too, but I can't remember what.

Back to the dual circuit systems: they all used to have dual reservoirs (post 67), but no longer (plastic, mostly single tank now). I believe that the proportioning valve switch has been improved, but not sure of that. In older units, when you had an imbalance in circuit pressure, a sliding switch in the proportioning valve would move over and close the 'brake' failure circuit (lamp in the dash would go on). I think there is a better word for the proportioning valve, but that is the most well known. It's been years since I had one trip (so much better materials today), but I recall it must have blocked the failed circuit, as pedal pressure increased (that could have been due to using the remaining brake circuit harder and requiring more pressure to get the brakes to slow you down).

 

[mojoinco]

Well, finally got the 'Maxbrake' controller installed. I couldn't find a better place to mount the head unit other than the right side of the top of the dash. I found the front fascia of the drivers side of the dash popped off with a simple tug. I had to add an additional 20" to the cable that attaches to the firewall. I didn't need to modify any other panel. I did slid the mesh that covers the cable up to the back of the controller end of the cable and added some heat shrink to cover the connector backside (in nicer connectors you have a backshell, but I don't think the Maxbrake folks thought the dash top mount would be common). I still had to use a tie wrap to hold it under the shrink wrap. It would have been nice to have had some 3:1 heat shrink handy. I had to pull the knee panel (2 screws) and the connector panel on the firewall (easy - tool free) to get to the body plug I used to pull the wire through. The most difficult part of it was adding in the 20". Next was the body plug (access was as much an issue). Nothing was particularly difficult.

I also took a black magic marker and made the exposed part of the cat/ethernet/rj45 cable black. The far end is the Honeywell pressure transducer connector.

I mounted the brake line 'T' to the rear brake circuit, as that was where there was room (you need to include room for bleeding). I wrapped the ~12" long extension line into a 'U' or 'J' so it didn't touch any other brake lines (vibration and wear). I put a piece of heater hose onto the transducer, but need an 'adell' style hose clamp around it and onto the master cylinder brake mounting stud. Bleeding was not even needed (I did it, but immediately had fluid -- yeah).

The line of sight over the controller is still below the hood line, and driver to display is pretty straight on (we'll see how ambient light and glare affect it). Calibration took maybe 1 minute. Manual control of the brake seems good (finger straight back to the dash and left, smooth). Now to put it to work!

Oh, forgot: the fuse panel under the hood. The top left is 'post #1' (trailer connector battery), the top right is 'post #2'. Post #2 may have to be connected (the posts are under the cover surrounding the fuse panel). That bit of info was easy to find (post #2 powers the controller). What wasn't obvious was is that post number 1 also needed to be fused. It had a dummy plug in the top left position, but the whole row had a sticker over them, so it was even less obvious. Nothing like wasting 20~30 minutes tracing this out.

My truck is a 2005 Chevy 2500HD -- I presume that this applies to ~1999-2007 (Classic) trucks.

 

[Diamondpilot]

Very cool and a nice job on the install. I am sure you will be sold and never go back to the old electronic style.

Chris