This story begins with the replacement of 6 backing plates and 5 drums on a 34' Airstream trailer. The work was done by a firm that maufactures and services trailers of all types and sizes. The service manager said that one drum was in good shape and did not need to be replaced.
After the installation, the brakes worked too well. The stops were very jerky at all speeds even with the Jordan controller set at it's lowest setting of 5 amps. Also the sqealing noise was terrible.
On the first trip one wheel locked up frequently ruining a tire. The brakes have been inspected and readjusted twice. I replaced the brake controller with a Tekonsha Prodigy.
The brakes are working better but they are still very noisey and lock up occasionally with the Prodigy set at only 3.5.
Your suggestions for resolving these problems will be greatly appreciated.
Well, to start with, in my opinion, you should have kept the Jordan. With it's built in ammeter, it can tell you a lot. Now, with 6 brake magnets, and the Jordan set up properly, you should have been drawing over 18 amps. You said you adjusted the Jordan to it's lowest setting and it read 5 amps. That would be less than 1 amp per brake magnet. Brakes should not have been grabby at that setting. Not familiar what "3.5" means on a Prodigy.
You said the brakes were checked out and adjusted TWICE. By whom? It seems to me that they are still out of adjustment. Are you sure they put the right backing plates on?
My guess "over the wire" is that they were never and are still not adjusted right. Very hard to diagnose without being there, so this is my best guess. Others will chime in with their thoughts.
Did they machine both the magnet and drum surface of the drum that was not replaced? That could be a potential trouble spot.
__________________
CP 9 miles off Exit 399, I75.
2003 GMC 2500HD 4X4 D/A Ext. Cab
Propane Powered Honda EU2000i
Lots of Hot Sauce! Air # 283
The Jordan controller did register about 15 amps on the old brakes. I expected about the same on the new ones. The Prodigy indicator shows what they call "power" with a range of 1.0 to 10.0. They have you set it initially to 6.0, then adjust until it until it just fails to lock up on full braking. That was 3.5.
The brakes were inspected and readjusted by 2 different shops than the one that installed them. Neither indicated that the wrong backing plates were installed.
They did not machine the one original drum. I may have that one replaced next.
I have just replaced everything on my Overlander, I think the backing plates are made by Alco ( or Alko?) I have got the Jordan Ultima and have to back it way off and even then they seem a bit 'grabby" at low speeds but won't grab hard enough to lock up. I think new brakes may need a break-in period so I will keep running them and see if it gets better. I had all the drums (both surfaces) turned at the same time.
Now regarding your problem. I am wondering if where you got your work done? What were to happen if they put a few or one of the left plates on the right and vice versa? The brake assemblies are specific as far as left and right. Maybe they got switched? Other than that I would look at the adjustment again. Any other ideas?
Chas - The brakes were replaced at Magnum Custom Trailer in Austin, TX in January. We then went on a trip to Arizona and California. The followup work was done by an RV repair in Yuma, AZ, at Magnum again upon our return and at Noah's RV in New Braunfels, TX.
on this one, if the backing plates got reversed the brake shoes may try to self engage.
also, the new shoes may have to be beveled on the leading edge. if this is not done the shoes will seem grabby, and will stay that way no matter how long you break them in.
i think that you should take the trailer back to the original shop and ask them to check the position of the new backing plates.
Man, all this talk is making me wonder if I even got mine put on right! Maybe I need to bevel the edge like John is talking about. I will pull one of mine off just to take a look at it. I have the Jordan Ultima and I have to run it at around 2 amps, way low so maybe I have problems as well? I have also heard that bad or loose electrical connections will cause problems also. I got my parts at Magnum as well, maybe they aren't the right ones?
But the electric brakes will not work at all if put on backwards. The magnet is pulled to the drum which in turn pulls the lever rearward and actuates a cam to expand the brakes against the drum. If put on backwards the movement is limited by the magnet/lever hitting the forward shoe.
There is a considerable amount of movement to fully engage the brakes to the point they will lock up.
My new brake backing plates-shoes-magnets and drums were really grabby, especially at low speed until I adjusted them.
Someone will let me know if I am wrong on this.
Here is a great site for information on electric brakes and how to troubleshoot them. Good info on the adjustment of teh controller and the use of a multi-meter in testing. http://www.dexteraxle.com/service_li...ric_brakes.pdf
i am not going to disagree with you because i had the same thought at first.
i went and looked at the diagram again, i believe the magnet would work in either position because it travels radially outward because of centrifical force.
however, my thought is that the piviot points on the shoes are placed before or after the center line of the axle. depending on what side of the axle it is installed on.
otherwise it would not matter left or right.
something must be wrong, these guys are starting with new parts and remachined drums.
if this is the way they all are, new trailer owners would be having problems too.
i still think beveling the leading edges of the brake shoes would eliminate a lot of the grabbyness.
one other thought, arcing the shoes to the drums could help too.
Thanks Gents,
I was back at Magnum yesterday. A friend of mine had his brakes replaced at Magnum after I did. He has had the exact same problems with them. They inspected his yesterday, readjusted them and replaced one tire that had worn flat spots from lock-up.
I found out the brand of backing plates that Magnum is installing. They are:
AL-KO, 12"X2", Pri GG, Sec GG, 1202-482 for right side
AL-KO, 12"x2", Pri GG, Sec GG, 1202-483 for left side
They now say that it is the shoe compound that makes them noisey and that probably will not improve.
So now there is another person who is having problems with the AL-KO backing plates on their A/S? I pulled off two of my drums last nite to have a look at the brakes and couldn't really find anything wrong with them. I did notice that the lining material was still fairly rough, had a good bit of texture to it which leads me to believe they need longer to break in or it is either a bad batch or the wrong stuff? What is the procedure with the sandpaper and would it help out in this situation? I would like to get another set of brake shoes from another source and put them on to see if that is the problem. I wonder if Bendix or Raybestos has an application for them?
Chas,
Today, I talked with the Service Mgr (Ted) at Southwest Brake & Alignment in San Antonio. They are on the East frontage road of I35 about 1 mile north of the SBC exit. 210 225-5577
He thinks there still may be something wrong with our brakes if they cannot be adjusted to prevent lock-up when the brake controller is working properly. He also said that he has brake shoes that will not squeal like ours.
Since we are both in Austin, if you want to call me, my number is 327-3181.
Chuck Surman
Quick Links
i'm with chas
Linear Mode
