Brakes won't "lock" during controller ck - Montana Owners Club

patodonn · 09-16-2005, 06:28 AM

Never have, two different controllers. I have to set my Prodigy at 10 or 11 (w/high boost set) to get what I think is reasonable braking of the RV. I know it shouldn't be necessary to set it that high.

When I do the low speed (~10 mph) "emergency braking" check with the Prodigy emergency lever, the RV wheels do not lock...good braking, but won't lock, even briefly.

Same condition a year ago using a Tenko controller. Never could get the RV brakes to "lock" during the check. Also, had the brakes changed and adjusted last Feb, adjusted again in June at a different RV shop.

Normal? If not, anyone else experience the same problem and found a solution?

Appreciate the assistance..best regards,

Bill and Ann · 09-16-2005, 08:53 AM

Our doesn't lock up either with the Prodigy. Set it for 6.8 or so with boost 2 and don't have any problems stopping.

tollmann · 09-16-2005, 02:48 PM

This seems to be a popular subject. Everyone has their own preference for brake settings especially with the Prodigy controller. I use 7.5 to 8.0 on boost 2. This works for my particular setup.

Bill Frisbee · 09-18-2005, 12:18 PM

I have done a bit of experimenting with my Prodigy as well. Have done the latest experimenting with a friend who is an instructor at a Truck Drivers School. According to his "educated" rear end, we have it set up just about right with simultaneous braking of truck and RV. Have boost set at 2 and gain at 7.5.

Also, got some advice from a more experienced hand who says that he reduces boost to 1 when in campgrounds to reduce brake lock-up/grabbing when just starting out.

My brakes do not lock when I test the trailer brakes using just the Prodigy ... but they do provide a nice, firm stop.

All-in-all, I am slowly developing confidence in my knowledge of the Prodigy, how to adjust the brakes, and the fact that they do work as advertised.

sreigle · 09-20-2005, 04:50 PM

Mine never locked with the Prodigy or any controller we've ever used with our Montanas. I guess they're just too heavy.

PJ, are you sure all four wheels are braking? I had my Prodigy set at around 8 (getting fuzzy on actual numbers but no more than that) and my dealer told me to back it off after he looked at the brakes. He said they were set too tight. They had heat stress cracks on the linings and the magnets were worn off to the point where soon the brakes would no longer release after braking. I backed them off to about 6.8 and had good braking at that level. So I wonder if you have one axle not helping on the braking?

drhowell · 09-20-2005, 05:40 PM

I check mine on loose gravel and can get them to lock and slide. I find a spot that I can roll straight ahead in neutral and just use the prodigy manual lever. Usually they only slide one or two ft. I put the pickup in park and set the brake, go back and check each wheel to see if I have about even skid marks in the gravel. I have never been able to lock them on pavement to the point of squalling. However the previous owner somehow managed to wear flat spots on two tires. So he had to have locked them on pavement and drug them awhile to wear down 1/4" of tread in one spot several places on both tires. He had moved them around so I couldn't tell where the problem really was. I just started from scratch and removed all wheels, checked the brakes and worked my way out from there. New shackles, new tires, new shocks and complete alignment and it is as good as new. So far no flat spots.

You may have the brake adjustments just a little loose if you can't get them to lock up. I adjust them in the air, bring them up as tight as I can get them past the point the wheel won't move. This helps to center the shoes. The I back them off one click at a time until the wheel starts to move. Then carefully one or two more clicks just so the wheel will rotate with a very slight drag. Usually the wheel will rotate freely except for a couple of tight spots where you can hear and feel it drag. If you back it off where there is no drag at all, they are too loose in my opinion.

patodonn · 09-20-2005, 05:59 PM

Had a conversation with a Prodigy Tech Rep today. He gave me some trouble shooting specifics. He also said that two of the same model/year 5ers, side by side, could easily have completely different settings on the controller to get the same braking action. Also that many 5ers will not attain brake lockup during the set up or checks. Has to do with the weight of the rig, the size of the wheels and size of the brakes.

Of interest, the number we set, up to 12, represents the controller's output voltage to the brakes. The movement of the emer lever is proportional..if you have 8 set, 1/2 throw of the lever gives ~4 volts TO the brakes; full throw gives ~8 volts (not 12). If you have 12 set, you would get 12 volts.

Controller voltage out TO the brakes doesn't always equal voltage AT the brakes. There are as many as 8 individual junctions in the wiring in my Dodge between the controller output and the connector plug TO the RV. Any of those can cause some voltage drop along the way. Also, the gage of the brake wiring in the truck and the RV is significant. 10 or 12 gage is prefered...I think our RV's is 16...even more voltage drop will occur over a long run.

In summary, lots of possible voltage drops between the controller and the brakes, so every case is different.

I do have some controller trouble shooting specifics, which I'll share if anyone who wants them (via e-mail). I am scheduling the rig for a couple of small maint items in Oct, including a bearing inspection and repack, brake inspection and trouble shoot the brake controller and voltages at the brakes. Thinking about getting the Dexter shackle kit installed at the same time...TBD.

Best,

OntMont · 09-21-2005, 04:25 PM

Mine don't lock either in normal breaking, but I did once accidently pull out the emergency cable while making a tight turn. That STOPPED it!

sreigle · 09-22-2005, 11:12 AM

Interesting information, PJ. Thanks. One more thing I learned today.

If the troubleshooting tips are unique to the Prodigy, then it won't help me. Otherwise please email them.

Thanks.
Are you and Nan going to make it to the rally?

Outahere · 09-26-2005, 03:27 AM

PJ and Nan We have the same trailer and truck (differant year) and we have never been able to "Lock Up" the brakes either. I agree with everyone else that is't a matter of adjustment. Even though, no matter where I set it, it will never lock them up. It must be the weight of the trailer. However we have noticed that when backing up the trailer, the trailer wheels will stay acctivated (almost Locked) even though I'm not using the truck brakes or the Prodigy. I have to roll forward some to get the trailer brakes to "Let Go" in order to continue to back up. I have no idea what that's about. If I ever find out I'll post it. If you ever find anything, please let us know

drhowell · 09-26-2005, 04:00 AM

When was the last time you had the wheels in the air and had the brakes adjusted? One of the signs of loose brake adjustment is the locking when backing? The braking systems on our Montana's do not adjust automatically like the ones on our tv's. At least the older units don't and I do not think the newest ones do either. The brake shoes on the Montana's are very small and IMHO light duty. If you have a loaded trailer and use the brakes normally you might need to adjust them every 5 to 10 thousand miles. That is where I would start troubleshooting.

Outahere · 09-26-2005, 04:50 PM

Farmer Don, These brakes have done this since everyting was replaced last year because of "Screaming Brakes" every time I used them. I have adjusted them also myself and they still do it. Soooo?

Thanks anyway for the suggestion.

sreigle · 09-27-2005, 04:57 PM

Hi, Mike and Karen (Bella too)! I see you're not in Waco anymore.

What solved my screaming brakes problem every time I applied the brakes was to back off the torque on the lug nuts. I had overtorqued them. I broke out the torque wrench, loosened the lugs, retorqued them to specs, and the screaming was gone. Of course, I had to retighten them each stop for about 4 stops before they stayed tight - the usual procedure. The brakes have not squalled like that in well over a year now.

drhowell · 09-28-2005, 04:16 AM

You say the brakes were replaced last year? And the problem started then? Brake shoes have a rear facing and forward facing lining. One lining is longer than the other. That is to keep the brakes from locking while backing. It is possible (not likely but possible) that the person who installed the brake shoes got them on backward. If they are backward your forward braking should be less positive then before. May not be able to lock the brakes when rolling forward.

Just a thought?

Outahere · 09-28-2005, 06:27 AM

Farmer Don, I know you don't know this but I am a semi-retired Mechanic and I hadn't even thought of that possibilaty

Now that's sad. I will definitely look at that. Thanks.
Steve, thanks also for that suggestion. What they did was to replace the "Bonded" shoes with "Rivited" shoes and they also replace the Drums. I have not had them "Squawl" since. I do have the Backing-Up problem though and will look into Farmer Don's idea! (Why didn't I think of that, I'm embarrassed) Thanks Guys

Bob Pasternak · 09-28-2005, 08:38 AM

Unless they're anchored top and bottom they are called "Primary and secondary" shoes. The rotation of the drum causes the front shoe to actually put more pressure on the rear shoe. There is a difference in length and, in some cases, the composition of the shoes differ.

drhowell · 09-28-2005, 11:41 AM

Figures a retired trucker would know about primary and secondary brake shoes. So how many times over the years did you setup the slack adjusters?

Hey Mike it is ok! Why would anyone expect new shoes were(may have been)installed wrong. Let us know if that is what it turns out to be.

Outahere · 09-28-2005, 05:07 PM

Ya, I will Don

Boy, that "ASSUMPTION" Thing could just have taken a big bite out of my a#$.

and to think I almost always "Watch" any work being done on my rigs. Don't take your eye off the ball!
Thanks all and in a few days I will look into this when I get some time to remove the wheels.

keham · 09-29-2005, 03:05 PM

I can get my 05 3475 to lock at 10 and under is set to 6.3 and b1. At first it didn't but I reset the hitch so camper is level when hooked up . and I can use lock lever and drag all wheel on dry payment in first or if at 10 hit the lever and tires lock and stops truck right now. I did redo every connection from brakes to controller to insure everything clean and tight. So am happy now.

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