Brakes on 3023

I have a question specifically of 3023 owners.  Just took ours out for the NYS safety inspection.

This has bothered me since we bought in 2000.  Regardless of settings on the controller, even in manual mode, I have never been able to get the trailer brakes to lock up.  They will gradually stop the tow vehicle in the driveway by themselves.

When I replaced the magnets last year, I verified that the brakes do indeed stop the trailer wheels virtually instantaneously when they're off the ground.  I'd expect that, but wonder whether the inertia of the trailer is the reason I can't get the trailer wheels to lock when towing.  If that's not it, I have to suspect the controller.

I'm intending to verify the actual voltage seen by the brakes as supplied by the controller, but wonder in general if 3023 owners see this.  It is my opinion that this model (1995 / 3023) is borderline a single axle trailer based on my measured weight and tire weight ratings.  Maybe it's also borderline for brakes?

Thoughts?

On gravel I can get my brakes to lock up but on dry pavement I almost can not.  I have a Tekonsha Prodigy and it stated I should "calibrate" the controller by adjusting the voltage so the trailer just about locked up at 25MPH when operated manually.  I did the best I could but I found it would just "bang" the brakes and slow the tow vehicle down before it would ever reach lockup.  For a while I ran the trailer this way but one day during a rainstorm I found out they will lock up in a panic stop.  Scared the beejeepers out of me because it started to jack knife.  This is not what I wanted to happen so I have since "backed off" the calibration voltage amount just until it stopped the "bang".  Later I read somewhere (maybe here but I do not remember) that I really just want max braking power when I calibrate and I do not want to hear the brakes "bang" when I manually calibrate.

To make a long story short it is very hard to get these brakes to lock up on dry pavement because of the inertia of the camper.  Adjust your brake controller to the point where they neither push you or pull you in a panic stop and make sure you adjust your brakes periodically.

Hi Dan,
I'm getting ready to get a controller for my vehicle, and the info posted on the gen. discussion under "brake controllers" helped me alot. One post talked about the difference in the low-budget models and high-end Prodigys or Jordans. Those guys on that post seem to know alot about controllers, so maybe they can help. Kinda sounds like your unit might be limited by design. I'll be buying a Prodigy and see if it owns up to all the hype. Good luck!

Dick

[RockyMtnRay]

Dan, FWIW, while moving I can't get the brakes to lock on my 2720SL either and it's most likely lighter than your 3023 (for one thing I don't have A/C). This is with the Prodigy controller set at full voltage for a manual brake test.

I can get the brakes to lock at near a standstill in my driveway by applying full battery voltage directly to the brake line pin in the connector so I'm confident they're adjusted correctly (and I just had them adjusted by the dealer during a spring tuneup of the trailer).

From Physics I recall that moving friction (i.e. between the brake lining and drum) is less for a given applied force than is static friction (this is why brakes tend to grab just as the wheels stop moving)...so it will be more difficult to lock the brakes at 25 mph than when stopped. Furthermore, the friction between two objects goes up with force acting on them...and since TMs are fairly heavy for single axle trailers, there's a lot of downward force on the tire patch which makes TM tires harder to skid than the more lightly loaded tires on other brands of trailers.

My thinking is similar to caremd99's...if, by using a proportional controller like the Prodigy, I need about the same pedal pressure to get the same rate of deceleration with or without the trailer...and my braking distances aren't noticeably different with or without, then it isn't terribly important if the trailer brakes can or can't be made to lock up on dry pavement in low speed testing.  And so far it subjectively seems that that is the case when I have the Prodigy set to around 9 volts in my manual testing.  With that controller setting, I did have to brake very hard one time last year from freeway speeds and sorta recall I was hearing intermittant squealing from the trailer tires as well as from the tow vehicle tires.

[Denny_A]

I have a question specifically of 3023 owners.  Just took ours out for the NYS safety inspection.

This has bothered me since we bought in 2000.  Regardless of settings on the controller, even in manual mode, I have never been able to get the trailer brakes to lock up.  They will gradually stop the tow vehicle in the driveway by themselves.
-----------------snip-----------
It is my opinion that this model (1995 / 3023) is borderline a single axle trailer based on my measured weight and tire weight ratings.  Maybe it's also borderline for brakes?

Thoughts?

I am not an expert on trailer braking.  However, I have developed "contaminated runway braking tables" for commercial airliners operated by my airline. So I am very familiar with braking coefficients. Let's say, based on my experience, that as road surface friction coefficient (measure of ability to adhere) decreases linearly, stopping distances increase non-linearly.

For example, a 12.5% decrease in friction coeff.  may result in a 15% increase of stopping distance, say going from .4 to .35.  Yet a 50% decrease from .4 to .2 can increase stopping by well above 100%.

Dry , grooved, new concrete may have a coefficient as great as 0.75 (where 1.0 would be zero slippage twixt tire and road), whereas an ice covered road can see a coefficient as low as 0.05 (or less). A wet road might be around 0.35 to 0.25. So where am I going with this?

The fact that a brake controller may not cause the trailer's brakes to lock-up on a dry road probably has NOTHING to do with the controller. If the max possible signal is sent from the controller to the trailer's brakes, the burden is now on the trailer speed/tire/weight/surface friction coeff./brake power, to determine if lock-up will occur.

Dry, grooved concrete road:  Trailer 95% of max. allowable weght., at 60 mph ---> probably NO lockup. Just too little brake "friction" on the discs to overcome the other factors posited, especially the power developed by tire-to-road contact friction.

Wet, grooved, concrete road: Same trailer speed, conditions as above (half the road friction coeff.)--> lockup may be easily achieved in such a condition.

Dry, ancient, oily blacktop --> maybe same results as on a wet concrete road.  Who knows?

Point is, there are any number of possible conditions to allow or prevent lockup. Having said the above, I haven't really worried about getting my brakes to lock up, when performing manual brake application (trailer only), during my initial 25 mph calbration on normal road surfaces. I just look for significant stopping force to be generated, and then fine tune during combined tv/trailer braking. I have a 2002 2720SL, which has nearly the same weight specs as a 3023. Therefore, your '95 may very well have underpowered brakes (or not  :-/).  

Obviously, I've been of no help at all. Not going to waste all this typing time though  ;D.

Cheers  -->  Denny_A