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ljmiii · 02-26-2007, 01:09 PM

I went to Jackson Center last week and upgraded my Bambi to Kodiak disc brakes with an Actibrake actuator (as well as the 4300lb axle, 15" wheels, and 225/75R15 Load Rating D tires...but those are addressed in another thread).

The stopping power of the disc brakes is truly amazing - but there are still some bugs in the system.

1. Very light braking (or using the manual control up to around 1/3) seems not to activate the trailer brakes. The drums did not have this behavior.
2. There is a delay somewhere just shy of 1 second between using the manual control and feeling the trailer brakes kick in. There appears to be a similar delay when using the brake pedal, but it is harder to tell for sure. The drums did not have this delay.

Reading though the Kodiak and Actibrake installation manuals and these forums seems to point to three suspects.
A. There may be too large a voltage drop between the prodigy and the Actibrake. Active Technology recommends installing the actibrake in the front of the trailer, but Airstream put it in the rear storage compartment (more or less above the axles).
B. There could be air in the brake lines.
C. thecatsandi mentioned that the actibrake needs to be calibrated to the brake controller after installation. I know this didn't happen since I had the tow vehicle while they did the installation. But thecatsandi's failure mode was very different - her actibrake went 'all on' at the slightest touch of the brakes.

So...I have a bunch of questions.
a. Does anyone have their Actibrake in the front of their trailer?
b. Does anyone know of any limitation on how long the hydraulic brake lines can be?
(I don't want to move my actibrake forward to fix the voltage problem only to find out that I now have a brake pressure problem).
c. Can air in the brake lines cause delay?
d. Has anyone else out there had an actibrake calibration problem?

thanks muchly in advance,
leo

overlander63 · 02-26-2007, 01:21 PM

Leo, I can give you some insight into how the system works.
Within reason, there is no limit to the length of hydraulic lines for the brakes, although if it is an issue, I would run larger wires to the pump's current location to combat voltage drop.
Air in the lines can indeed cause a delay, as the pump will have to compress the air in the lines before it can move the fluid.
Not having it calibrated can also cause this problem, as well as the "full on" or grabbing, problem.

2airishuman · 02-26-2007, 03:48 PM

ok leo

first going through 3 separate threads to get to here...

it's all one topic bro, too many clicks.

i've got the system on a 34 so long lines work fine. airplanes have very long lines...

yes my actibrake is in front in the tongue battery box. most are.

a/s put yours where they could find space.

cats calibration issue is specific to the ford controller...

air in the lines would could give a spongy feel which might be interpreted as delay.

this isn't a delay in activation it's a delay in stopping...

surely the prodigy requires calibration initially.

any time the actibrake controller board is disconnected it needs to be recalibrated.

but that doesn't mean disconnected from your tv, i means internally board from mechanicals.

the brakes work great don't they?

cheers
2air'

3Ms75Argosy · 02-26-2007, 03:54 PM

but why don't you try calibrating the Prodigy and see what happens?

Also, FWIW - you may be able to use the "boost" feature to eliminate the lag a bit (see the manual for the operation of the brake controller - I've set mine but can't remember how to do it without going outside). For example, my drum brakes did have a lag before they started to bite. The boost figure increases the amount of voltage to the brakes at iniatial braking. It can be adjusted by 2-3 modes as I remember.

I think there may be two issues here. The Actibrake does have a .6 sec delay to get to full "boost" per their manual (this is the pump up time). You say there is a gap of about 1/3 using the manuel control on the controller to get the brakes. I think the boost feature on the controller will get you past this dwell time with the pump.

HOWEVER - I really think you should calibrate it first. That may be the whole problem. It's pretty easy from what I read (I'll be doing the upgrade shortly myself - I have the Actibrake, just need the axles and brakes and some more $$).
Marc

ljmiii · 02-26-2007, 05:14 PM

Quote:

Originally Posted by 2airishuman

first going through 3 separate threads to get to here...it's all one topic bro, too many clicks.

Sorry, ever since a moderator moved my thread I've tried to 'single purpose' my posts - axle in axle, brakes in brakes, etc.

Quote:

Originally Posted by 2airishuman

[lots of good brake info]...the brakes work great don't they?

Thanks for all the good brake info...and yes, the new brakes are AMAZING.

thanks,
leo

ljmiii · 02-26-2007, 05:22 PM

Quote:

Originally Posted by 3Ms75Argosy

no offense here...but why don't you try calibrating the Prodigy and see what happens? [followed by good info/suggestions]

Sadly, because my Bambi is currently a snow covered sculpture about an hour and a half away. And once we get a thaw my debugging session will have to happen as quickly as possible because my 'lab partner' is my wife and my 'lab assistants' are aged 3 and 2 and tend to blow up if things are too boring for too long. So...I'm hoping to preplan as many experiments as possible before the testing goes 'live'.

thanks,
leo

Zeppelinium · 02-26-2007, 05:22 PM

somebody said they saw the Actibrake pump on sale for around $500 somewhere. Anyone have a clue? I don't get any hits on Google for sources. (not intended to be a hijack...)

Despite all the advice about calibrating the Prodigy, I'd check for air in the lines first. I don't know what the pump volume is on the Actibrake, but I suspect it's pretty small and relies on the incompressibility of the brake fluid in order to active fast action. Any bubble would defeat that.

Zep

Phil Gobie · 02-26-2007, 05:51 PM

My control has two adjustments one is basically how abrupt the brakes come on and a second for how much power. I think the prodigy name has different models. Be sure the one you have is compatible with the hydraulic brakes. The proper bleeding is also key. And a small difference could be in the type of hydraulic lines. Steel are better than rubber flexible type of lines. The steel don't expand like the rubber type. I don't know if you could detect the difference on this application though.

ljmiii · 03-04-2007, 09:09 AM

Quote:

Originally Posted by ljmiii

Reading though the Kodiak and Actibrake installation manuals and these forums seems to point to three suspects.
A. There may be too large a voltage drop between the prodigy and the Actibrake.
B. There could be air in the brake lines.
C. thecatsandi mentioned that the actibrake needs to be calibrated to the brake controller after installation.

Experiments were conducted yesterday. The voltage was fine. The brake fluid level was fine. And calibrating the Actibrake seems to have helped braking initiated by the brake pedal. But braking using the manual control on the Prodigy still is not as responsive as the drums. And so I have a pair of followup questions:

1. Does anyone else out there who upgraded from drums to discs notice the same 'problem' when they use their manual control? Or is this just a feature of how the electric to hydraulic system works.

2. How often do you bleed your brakes? And do you need to take this to a trailer guy or will a 'normal' auto repair shop do? Or do most of you bleed the brakes yourself?

thanks again in advance,
leo

thecatsandi · 03-04-2007, 09:16 AM

With everyting hooked up put a Digital Volt Meter between the frame of the TV and the frame of the trailer. If there is any voltage reading you have a bad ground between the truck and trailer. If you hit the brakes with the traielr runnign lights on do they dim?

ljmiii · 03-04-2007, 11:01 AM

Quote:

Originally Posted by thecatsandi

With everything hooked up put a Digital Volt Meter between the frame of the TV and the frame of the trailer. If there is any voltage reading you have a bad ground between the truck and trailer. If you hit the brakes with the traielr running lights on do they dim?

No voltage reading...and the lights don't dim. Thanks for the hints though.

enjoy,
leo