Disc brake discussion

[GCinSC2]

Originally Posted by BoldAdventure

Why is the sky blue?

Now to off to research weather or not I really want to do that disc brake conversion.

BoldAdventure,

Suggest a new thread for that question, but here's a idea to start it off. Have you driven a rig with hydraulic brakes just to see what they feel like? I think if you could compare very similar rigs with and without that could be interesting.

Gary

[Inland RV Center, In]

Originally Posted by BoldAdventure

Now to off to research weather or not I really want to do that disc brake conversion.

Why??

Everyone knows that disc brakes are many times superior to electric trailer brakes.

Yes, it costs a few bucks, but the margin of safety vastly improves.

The cost of safety, is meaningless when it comes to saving even one life.

Andy

[BoldAdventure]

Andy that sounds like an endorsement.

[rmkrum]

Andy, How hard to make the change?


Sent from my pocket Internet using Airstream Forums

[Pahaska]

I agree with Andy. After 8 years of disc brakes, I would never go back to electric brakes; I consider electric brakes a kind of kludge that happens to be cheap to implement.

[Inland RV Center, In]

Originally Posted by rmkrum

Andy, How hard to make the change?


Sent from my pocket Internet using Airstream Forums

Stickly labor, no tecknical required.

Instructions come with our kits.

Andy

[rmkrum]

Do you get a long delay between going to the brakes and the AS brakes going on?


Sent from my pocket Internet using Airstream Forums

[JimAspinwall]

First, I don't understand this as a comparative.

Disc vs Drum yes, hydraulic vs electric yes.

Disc vs electric - not. Electric braking would seem to imply a purely electromotive force/resistance (ala Tesla, Prius, etc.)

One is the physical form implementation, the other is the actuator drive scheme.

We know there are both hydraulic drum and hydraulic disc brakes systems.

I know there are electric drum brake systems, common on trailers, which we mostly all have (electric vs. hydraulic solenoids pressing the shoes to the wheel housing)

Are you saying there is an electrically-actuated disc brake system for trailers? It's possible, just not well-known. Otherwise I could not imagine implementing hydraulic brakes on a trailer driven by the tow vehicle system, but I suspect their could be a hydraulic pump operated off the 'TV' electric brake source.

If so... make, model, vendor, web reference... and in addition, if there are specific products/implementations for Airstream (preferably validated by the factory.)

[Pahaska]

When I said electric brakes, I was simply referring to drum brakes where a magnet is used to actuate the braking. The disc brakes are commonly referred to as "electric over hydraulic" meaning that an electric signal is used to control the hydraulic pump. In drum trailer brakes, electric directly operates the brakes.

[GCinSC2]

Originally Posted by JimAspinwall

Are you saying there is an electrically-actuated disc brake system for trailers? It's possible, just not well-known. Otherwise I could not imagine implementing hydraulic brakes on a trailer driven by the tow vehicle system, but I suspect their could be a hydraulic pump operated off the 'TV' electric brake source.



If so... make, model, vendor, web reference... and in addition, if there are specific products/implementations for Airstream (preferably validated by the factory.)

Short answer, yes. Hydraulic 4 piston/caliper Dexter disc brakes actuated by an electric motor/pump combo knows as an actuator.

Someone asked about a delay in actuation, negligible if at all. Any report of delay first inspection is for air in system.

Andy put it pretty clearly but until you drive it, hard to appreciate it. Pretty sure it was std. Equipment on my '07.

[dznf0g]

Delay depends mostly upon actuator manufacturer and/or the controller brand. But, as GC says, when properly bled, delay is minimal.

[switz]

When doing our hydraulic disc brake installation, the axles were NOT changed. In hindsight (which is always 20-20), I should have installed the Kodiak disc brakes with the sensor ring so ABS could be added in the future.

We ran into a problem with the distributor/vendor failing to mention to our installer that the disc brake hydraulic pump system we were ordering (Titan BrakeRite II SD which is a split system so electronics are separate from the pump for easier service) was incompatible with nearly all OEM truck brake controllers.

Due to the major solar battery system installation also happening at this time, the original battery box was empty and became the home for the hydraulic brake pump and it's separate control module.

This incompatibility discovery showed up as very erratic brake application coming through the mountains in the dark on the way home from the installation. No settings on the truck's trailer brake control system could resolve the issue.

I then started research for a compatible brake controller. The issue was to find one that could be installed and not have the Dodge Ram throw error codes for not using their OEM brake system.

We went with the Tuson DirecLink NE (can be used with their ABS system) brake pump controller and were able to wire it into place so no error codes were generated by the Dodge computer. It plugs into the OBDII port so it knows when the truck brakes are touched as well as when the accelerator pedal is eased off. Our DirecLink NE OBDII installation was in parallel with our Edge Insight engine gage and control system. One can fine tune the DirecLink NE settings and adjust for the GVW of any given trip.

The wiring work around was very simple to implement and the Dodge brake system was not impacted. I think the same bypass idea would work with other brands of truck.

[Pahaska]

I installed two brake magnets on the storage box behind the propane tanks and wired them into the blue brake wire in order to use the built-in controller in my 2013 Silverado. The truck thinks it is seeing a drum brake system and the built-in controller works just fine. Braking has always been very smooth with this piece of southern engineering. Without the magnets in the circuit, the truck controller does not detect the trailer.

[GCinSC2]

Folks,

Not sure how this started as a new thread, I just made a suggestion to separate a brake question from tires. I don't have the powers AFAIK to break it out.

Gary

[dznf0g]

Mod did it and explained it in the other thread.

[KJRitchie]

Is it difficult to bleed the brakes on an Airstream with disc hydraulic brakes. Maybe I need to do this as I have some delay.

Do you just get someone to move the manual brake lever on the brake controller to get the pump to apply pressure then open the bleed valve on each wheel? Top off the pump reservoir after each wheel is bled?

Kelvin

[dznf0g]

Kelvin, if you still have the original actibrake, just pull the breakaway switch pin. Pump will only run 20 seconds with pressure on the system, then shut off. Open the bleeder, pump turns on, purge air, close bleeder, pump turns off. No helper needed.

HOWEVER, getting the air out of the inner caliper half is a challenge. I crack the line fitting, but am never confident I am getting all the air out of the inner half.

[SteveH]

There are several different types of hydraulic brake calipers, and electric actuators available. The biggest difference is the single piston vs. four piston calipers. The four piston calipers are almost impossible to properly bleed, IMHO. That is because each caliper has two resevoirs, but only one has a bleed valve. SO, DEXTER, HOW DO YOU GET ALL THE AIR OUT OF THE OTHER RESEVOIR?

They say to bleed them "fast", whatever that means, but I've tried bleeding them as "fast" as the actuator will go, but still have unacceptable delay. Actually tried self-developed methods that work better.

Our 34' has the four piston calipers, and came equipped with the Actibrake actuator (no longer built, and that's a good thing because most all of them eventually fail, as did ours). We now have a Dexter Actuator, and the last time I hooked up the trailer about a week about just to move it so I could do some lot maintenance, the Dexter also failed in the on condition and would not shut off. Even after bleeding this system three different times, it still has what I consider unacceptable delay, and Dexter says about a one second delay is the best they can do. One second is a long time traveling down the road a 65MPH when some fool pulls out in front of you.

Having towed trailers since the early 70's with electric brakes, I never had one fail, and we've owned this trailer about 13 months and all I've had is trouble with the hydraulic brakes. After you can get them to come on, and you stand on them, they STOP. But, wish I had electrics. YMMV.

[KJRitchie]

That sounds like the same experience I'm having about a 1 second delay. I have the Dexter actuator vs the Actibrake. I also have what looks like a trailer brake magnet in parallel in the electrical wiring to the Dexter actuator (one wire splices into the wire to the Dexter and the other magnet wire is screwed into a ground). My Prodigy P2 is set to electric over hydraulic but with the magnet connected maybe it's confusing things however I remember when I first got the trailer it was set on electric brakes and after changing it I thought the brakes worked better. I have to set the P2 gain very low, around 1.4 otherwise the trailer brakes will be too aggressive.

It sounds like my brakes don't need to be bled since the Dexter was installed March 2013 and the trailer hasn't been heavily used. Brake pads have plenty left.

Thanks

Kelvin

[dznf0g]

Yeah, Steve, a bleeder in the inboard caliper is the fix for most of our woes relative to bleeding. I have found the only way to "easily" bleed the inner half is to loosen the supply line so it leaks very slowly....somewhere between a weep and a leak and watch until no bubbles come out. Then proceed to the normal bleeding method for the outer half. I'm still not sure you get all the air that way.

There is another way, but it would take 2 people, maybe a fabbed fixture, and some acrobatic dexterity. I hesitate to post it, as I haven't tried it and it could pose some risk of injury unless you are very familiar with potential ramifications of high pressure while the caliper is removed from the hub and disc.