Hydraulic Brake System Questions

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Kelvin,

Anybody around you that has a tow vehicle with a Maxbrake in it? Any chance to do a test drive with it?

My experience is limited to the Maxbrake only.

On our last trip out approaching a busy intersection multilanes, retail all around I hit the dreaded spot when the light changed DO I STOP OR RUN? I was right at that decision spot and now or never. I chose the brakes. Did not reach for the controller I don't think that is a correct choice, applied the brakes with a firm strong application. My rig stopped a foot or two over the paint stripe, in control and smooth. I feel that my disc brakes and Maxbrake have made for a smooth strong braking package. And I have previously posted about my .02$ and observations about "hydraulic delay" on my rig, almost nothing.

[KJRitchie]

I never heard of Maxbrake until I started frequenting the Airforums. I'll check them out if I feel the Prodigy P2 is not working. In the short trip from dealer to storage, 60 miles, I wasn't aware of any delay. I know I apply the manual lever on the P2 controller when just creeping along the trailer brakes seem to react instantaneously. This is with a new Dexter actuator.

Kelvin

[KJRitchie]

How do you know the brake controller is adjusted correctly. When the controller is adjusted correctly is the braking supposed to be like it is when driving the tow vehicle solo or do you have to press harder on the brake pedals even if the controller is set correctly. It always seems I have to press the brakes on the tow vehicle harder. I have my Prodigy P2 set to about 7 with 1 boost. When I pull the manual lever the trailer seems to pull back on the TV when I at about 20 to 25mph.

Kelvin

[DKB_SATX]

I don't know how much this differs for disc brakes, since they don't lock up so easily.

Generally you want the controller at full manual application to ALMOST lock the wheels at 25-30. With drums, you want to have driven some and applied the brakes several times before running this test so the brakes aren't cold but aren't overheated. I'm guessing that the "warm up" part of it won't particularly matter to a disc system. On a cool day it might make a difference if the tires are warm vs. cold, but above freezing that shouldn't make a huge difference.

With my Prodigy P3 set at boost-1 (on my drum system), I feel the trailer dragging as soon as I touch the brake pedal, but it takes a little deceleration from the truck brakes to set off the controller's accelerometer and really clamp the trailer brakes. I suspect that's similar to the result you want with discs as well, so finding the gain setting where it will just barely lock the trailer brakes at max manual application at 25-30 mph and then backing off that a bit is a good place to start. Remember it'll almost never apply that much voltage when you're stopping with the brake pedal, just when you're using the manual control.

[Don.44]

Who sends you these recalls ? I have a 2005 Classic and the brakes have a lag between the tow vehicle and the trailer The brakes work fine once they are applied but there is defintly a time laps between trailer and tow vehicle . I called AS once and they just blew me off .

[KJRitchie]

Now that I have a few towing miles under my belt I've noticed the lag with the disc brakes. I've got a Dexter actuator. I've got a Tekonsha Prodigy 2. I've set it with Boost 2 now to see if the trailer brakes will activate differenty. I don't feel its unsafe, the trailer brakes will activated in a panic stop, its just when braking from a cruising speed I feel the TV brakes are doing all the work.

Kelvin

[Silver Goose]

I also have a P2 controller and the Dexter actuator. My opinion on the lag is that the motor has to pump up the master cylinder in the actuator to a given pressure before the trailer brakes take effect. Initial voltage to the pump occurs the instant the brake light circuit becomes active and then the inertia mechanism in the controller determines the amount of voltage applied. I really think the delay is the nature of the beast and I'm not aware of any way to eliminate it, but proper settings may reduce the sensation of the lag.

The maximum voltage applied to the actuator is set with the dial on the P2 controller. There are a number of factors that determine what is optimal and for me this is a seat of the pants feel of what's going on. Ideally the trailer brakes will work in harmony with the TV brakes such that they carry the mass of the trailer. In a panic stop, you want the maximum amount of power applied to the brakes that doesn't lock up the wheels. For my particular combo, 6.8 volts seems about right. If I understand the boost function, it determines the amount of initial voltage sent to the actuator. For me, b3 seems to be the correct choice, but when the brakes have warmed up and I'm in stop and go traffic, I find the brakes become grabby and work more smoothly if I drop down to b2, then once back on the highway, I bump it back up to b3. I'm not suggesting these settings will be the best for you, but you will find what works best with some experimentation.

Significant changes such as traveling with full water tanks vs empty may alter the sweet spot. In particular, changes in road surface must be considered. The amount of power applied to the brakes on dry pavement may be too much for wet and particularly for icy pavement. I wish Dexter had considered adding ABS to the actuator as this may have assisted with the slippery pavement issue.

[JFScheck]

P3 Controller with 2009 Classic 25FB - great combo, smooth and controlled breaking with zero delay via my wiring harness I had to create for use with my TDI Touareg.

Interesting side note, my 2011 30 Classic and now my 2013 27FB International - both with drums brakes, feel the same as my disc brakes on the 2009 25FB Classic.

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http://www.airforums.com/forums/f439...ime-96724.html

FWIW The above is my effort at tying to document my work on my disc brakes. My truck and trailer brakes act together. My experience is limited to EOH and Maxbrake.

[KJRitchie]

Originally Posted by Don.H

Who sends you these recalls ? I have a 2005 Classic and the brakes have a lag between the tow vehicle and the trailer The brakes work fine once they are applied but there is defintly a time laps between trailer and tow vehicle . I called AS once and they just blew me off .

I found out about the recalls researching on this site. There is the Actibrake recall where a small hole is drilled in the motor/electronic casing and if brake fluid comes out then the Dexter unit is installed otherwise nothing else is done.

The second recall is for the brake lines.

I'm not sure if either of these recalls was for brake lag. Seems some of use have it and others don't. Maybe the difference between brake controllers.

I watched the Tekonsha video and for Prodigy 3 its showed in the menu setting a electric over hydraulic setting. The P2 doesn't have that.

Kelvin

[Silver Goose]

Originally Posted by KJRitchie

...
I watched the Tekonsha video and for Prodigy 3 its showed in the menu setting a electric over hydraulic setting. The P2 doesn't have that.

Kelvin

Early versions of the P2 manual stated that the P2 did not support electric over hydraulic systems. The one I bought 3 years ago said it did on the box and the manual packed with it had removed the above statement and added a section on how to put it into E/H mode.

The way you can tell which mode it is in is to look at the display. Lower case c indicates E mode, upper case C indicates E/H mode.

[KJRitchie]

I've never set my Prodigy P2 for electric over hydraulic. I bought my P2 in 2010 when I bought the Casita. I downloaded the instructions and will try to see if my P2 has the Electric Over Hydraulic Mode. I've been towing my Classic on the electric brake mode. Lets see I've probably got about over 1000 miles of towing on it since I bought it on March 30, 2013 using the P2 in electric mode.

Funny, the dealer I bought my AS asked me about my controller but didn't ask if I had switched it over to to electric over hydraulic mode. I'm beginning to think dealers are only there to sell, forget about anything technical.

Kelvin

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Kelvin,

EOH brakes are the minority and IMHO subject to some assumptions including a one size fits all controller mistake. My dealer installed an incorrect one, just didn't know it required a compatible unt. I don't know what is different, but on this topic I want the controller mfgr to say, EOH OK.

Singer Goose added some good info above too.

Gary

[KJRitchie]

Since my last post I was able to find the procedure to switch my Prodigy P2 to electric over hydraulic and the braking seems better now.

My next question has anyone tested the break away switch on a hydraulic system. I had the two recalls performed when I bought my Classic and insisted they replace the Actibrake controller with a Dexter 1600.

I have noticed the wires for the break away switch go underneath the propane tank cover and are getting pinched. I want to lengthen the wires to avoid that path. What gauge wire should be used?

The Dexter manual shows the yellow wire from the hydraulic controller connects to the break away switch and another wire from the switch connects to the battery but I think the break away switch on my Classic has a third wire.

Luckily where the wires are being pinched by the propane tank cover are where the wires from the switch are connected to the trailer with crimp connectors so the weight of the propane tank cover is resting on the crimp connectors.

Thanks

Kelvin

[Blockparty]

I’m looking for some help identifying an object that I discovered while rebuilding my 77 Sovereign. It’s a black tank (rusted through)that had a black rubber hose attached which ran to the front of the trailer where, in the A frame, is a hydraulic brake system. I’ve attached a pic. Anyone familiar with this?

[Blockparty]

Originally Posted by blockparty

i’m looking for some help identifying an object that i discovered while rebuilding my 77 sovereign. It’s a black tank (rusted through)that had a black rubber hose attached which ran to the front of the trailer where, in the a frame, is a hydraulic brake system. I’ve attached a pic. Anyone familiar with this?

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Did the hose just push on to a barbed fitting or a pressure hose that threads on?

What did the hose connect to at the other end? Got a pic of it?

Mystery vessel, no cap to fill with mystery fluid?

Super swag in head trying not to let it out w/o a bit more info.

[Action]

Vacuum boosted hydraulic braking system?

That is a vacuum reservoir!?

>>>>Action

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Originally Posted by Action

Vacuum boosted hydraulic braking system?

That is a vacuum reservoir!?

>>>>Action

Action,

That's where I was headed but never seen one, couldn't be sure.

OP,

If rig has disc brakes that still have life in them, ditch the vacuum booster master cylinder and install a Dexter or Hydrastar https://www.hydrastarusa.com/products/hydrastar/ actuator.

Gary

[Action]

Me neither just a guess on my part

>>>>Action