Disc brake discussion

[barts]

We have Kodiak calipers and a Carlisle actuator on our 1971 dual axle Tradewind. This has worked beautifully from the day I installed everything as part of an axle swap. We use Michelin radials and the stopping performance is excellent. The only problem is that we don't always get stuff stowed in the trailer well enough to keep it in place under emergency braking.

One trick for bleeding is a remote switch to turn on the actuator while under the trailer; this lets one do the bleeding w/o an assistant. Frequent refilling of the actuator is required, however; perhaps i'll rig an IV-style fill for that purpose the next time I do this.

I do wish I could find a brake controller that was like the Max-Brake, though; having trailer brakes be proportional to truck braking would seem to be ideal. W/modern trucks having integral controllers, the market for sophisticated add-on controllers is disappearing.

- Bart

[SteveH]

Does anyone know if the Dexter actuators incorporate a residual valve?

Judging from the way the sound and work from start-up, they do not.

[dznf0g]

Originally Posted by SteveH

Does anyone know if the Dexter actuators incorporate a residual valve?

Judging from the way the sound and work from start-up, they do not.

If you mean a high pressure accumulator, I don't think so. Neither I nor the Tuson Engineer are aware of any trailer actuators which utilize an accumulator.
That would, IMO, solve many issues with delay.

[dznf0g]

Originally Posted by barts

We have Kodiak calipers and a Carlisle actuator on our 1971 dual axle Tradewind. This has worked beautifully from the day I installed everything as part of an axle swap. We use Michelin radials and the stopping performance is excellent. The only problem is that we don't always get stuff stowed in the trailer well enough to keep it in place under emergency braking.

One trick for bleeding is a remote switch to turn on the actuator while under the trailer; this lets one do the bleeding w/o an assistant. Frequent refilling of the actuator is required, however; perhaps i'll rig an IV-style fill for that purpose the next time I do this.

I do wish I could find a brake controller that was like the Max-Brake, though; having trailer brakes be proportional to truck braking would seem to be ideal. W/modern trucks having integral controllers, the market for sophisticated add-on controllers is disappearing.

- Bart

Bart, the Direclink does monitor, and act upon, the OBDII data stream. Although the Tuson Engineer would not delve deeply into their proprietary programming, he has hinted that the TV brake line pressure is part of that programming. So, apparently, although it does not tap into the hydraulic line, (which makes me nervous anyway, as a mfr rep) it gets and acts upon that info. I can't say it for sure, but I do know the Direclink feels much better than any other controller I have used. I have not experienced the MaxBrake, but understand it performed very well.

[dznf0g]

Originally Posted by J. Morgan

The trailers I have primarily use 10,000 pound Dexter axles with disk brakes, they have been very reliable, especially once I switched to Dexter actuators.

The primary issue I have had is that two 30 amp circuits are required to reliably operate the actuator, one from the battery, and one through the brake controller.

Most of my road failures have been because of a failure of one or the other of these circuits.

The wheel units have been perfect. I have never had to replace a rotor and ALL of my brake pads have lasted for over ten years.

If AS cant do this with their systems, (or aftermarket) then they suck, and they aren't trying hard enough.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

I, likewise, have had zero issues....lucky???? My Actibrake was not one of the recalled units, and works perfectly....but for how long? My rubber lines are plenty long enough with no kinking. They did contact the frame though, so I wrapped them with fuel line as an isolator. I have had no caliper performance issues and my rotors look virtually new, with no groves in them even.
My interaction with the Direclink Engineer was to inquire about application lag, and see if that was something they address with their actuator. My initial contact was to inquire about re-programming mine to an "NE" model, so I could be ready for an easy replacement with their actuator when the time comes, maybe ABS and Sway control as well. (haven't decided on that yet..$$$$$).

This led to over 20 emails and several phone conversations about future product enhancements, and performance algorithm tweaks. I found this company to be VERY interested in customer feedback, and several of the items, like a screen color change to accommodate sunglasses wearers (particularly polorized), putting screen brightness controls on the main screen, and some others are already being worked on for next gen product.

I like companies that are interested and spend time with customers and really listen.

[SteveH]

Originally Posted by dznf0g

If you mean a high pressure accumulator, I don't think so. Neither I nor the Tuson Engineer are aware of any trailer actuators which utilize an accumulator.
That would, IMO, solve many issues with delay.

Back when I was building street rods, we always used what we called and was marketed as a "residual valve" in the brake line between the master cylinder and the system. We used a 10lb on the rear if it had drums, and a 5lb on the front for discs. It was a small, 3/16" in line unit, just a little larger than a union, and they would give you a much firmer and better feeling brake pedal, eliminating the feeling that you needed to pump the brakes.

I'm thinking one of these 5lb "residual valves" might reduce the delay.

http://www.summitracing.com/parts/wi...3278/overview/

[J. Morgan]

You might be on to something Steve.

In building cars it was kind of a rule that cars with low mounted master cylinders, like street rods with the master cylinder under the floorboard, that the caliper pistons would tend to retract too much when the fluid was pushed back in the MC.

If memory serves me, in these cases, where the MC was low mounted, I would use a 5 or 10 psi RPV on drums, and a 2 psi RPV on disk.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[dkottum]

Mount the pump higher?

[Pahaska]

Originally Posted by dkottum

Mount the pump higher?

My pump is mounted alongside the storage box behind the propane tanks. The line goes out of the pump just about dead level along the belly pan. When I was bleeding the brakes, I first raised the tongue high so that any bubbles would tend to come back into the reservoir, then lowered the tongue to help urge any bubbles back toward the calipers. One bleeding did a good job of eliminating lag.

[SteveH]

Originally Posted by dkottum

Mount the pump higher?

Doug,

My pump is mounted where the factory mounted it in the storage box behind the propane bottles, or where the batteries are mounted in some models. I suppose it could be moved but it would really be vulnerable to damage in most any other location.

[Bill M.]

"To address the other post about calipers becoming stuck.....not multi-piston calipers where pistons are on both sides of the rotor. On those, the caliper is fixed and all motion is in the pistons which compress each pad independently. Single piston calipers slide on the knuckle, or hub flanges. If those sit for an extended period (like years), they can stick and cause h"

I am looking hard at the Dexter axles. The disc brake option they show (3500 lb axle) certainly looks like a single piston caliper that slides on bolts to me. Is that not what Airstream uses also? Is that a reason to avoid the Dexter? Or maybe to buy it since it should bleed fine?

[SteveH]

Originally Posted by Bill M.

"To address the other post about calipers becoming stuck.....not multi-piston calipers where pistons are on both sides of the rotor. On those, the caliper is fixed and all motion is in the pistons which compress each pad independently. Single piston calipers slide on the knuckle, or hub flanges. If those sit for an extended period (like years), they can stick and cause h"

I am looking hard at the Dexter axles. The disc brake option they show (3500 lb axle) certainly looks like a single piston caliper that slides on bolts to me. Is that not what Airstream uses also? Is that a reason to avoid the Dexter? Or maybe to buy it since it should bleed fine?

Just my opinion, but I would prefer the single piston caliper because they are easy to bleed.

[J. Morgan]

The Dexter calipers on my Dexter axles (as mentioned above) are one piston designs that have proven bulletproof over decades.

Not a single failure to report here ever, nothing.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[dznf0g]

Originally Posted by Bill M.

"To address the other post about calipers becoming stuck.....not multi-piston calipers where pistons are on both sides of the rotor. On those, the caliper is fixed and all motion is in the pistons which compress each pad independently. Single piston calipers slide on the knuckle, or hub flanges. If those sit for an extended period (like years), they can stick and cause h"

I am looking hard at the Dexter axles. The disc brake option they show (3500 lb axle) certainly looks like a single piston caliper that slides on bolts to me. Is that not what Airstream uses also? Is that a reason to avoid the Dexter? Or maybe to buy it since it should bleed fine?

The ones used on Classics (and optional on others, I think) in the mid 2000s are 4 piston calipers. Not sure what Dexter uses now. The Classics went back to Electric brakes in 2011 or 2012.

I'd probably prefer a single piston E/H as well. If the 4 piston were executed properly, I'd prefer them, but the single piston would certainly be easier to maintain.

[dznf0g]

It looks like here:

http://dexteraxle.com/i/u/6149609/f/...rake_Flyer.pdf

That 3500# are single piston and >3500# are 4 piston.

[KJRitchie]

The pictures in that document show the bleed valves on the top with the supply lines on the bottom on the inner and outer calipers. Is that not what my 2008 Classic calipers look like? Should be easy to bleed all the air out on those calipers. My Classic is 8000 GVWR.

Kelvin

[dznf0g]

Originally Posted by KJRitchie

The pictures in that document show the bleed valves on the top with the supply lines on the bottom on the inner and outer calipers. Is that not what my 2008 Classic calipers look like? Should be easy to bleed all the air out on those calipers. My Classic is 8000 GVWR.

Kelvin

No, they have the supply fitting on the top of the inner housing, a "transfer line" joining the two halves, at the bottom of the halves and the single bleeder on the top of the outer. Pics don't show the bottom nor the inner half in deatil.

[dznf0g]

http://www.dexteraxle.com/i/u/614960...t_6K_7K_8K.pdf

Note, the axle is uoside down on the floor in these pics.

[dznf0g]

Dexter Axle - Trailer Axles and Running Gear Components - 8K Disc Brake

The bottom pic shows all four fittings pretty clearly.

[cwf]

Interesting.. Wonder if actuators can handle 6 brakes? ����