Dexter Brake Inspection Criteria

[Tarheel]

I have just pulled a wheel to do my annual spring inspections. Because of the mileage that I have put on the trailer ( about 30k-40k) and knowing that I have only replaced one brake because of a spring failure I felt like a brake job was in order. I have replacement brakes on hand, these are from another Airstream with about 2k-4k miles on them. There is very little difference in wear between the brake that I looked at on the trailer and the replacement. I do have one new brake to use as a comparison. The magnet on the new brake as a waffle pattern in the steel and 4 small holes in the ceramic magnet. Brakes on the trailer show no waffle pattern in the steel nor do the replacement brakes. My magnets are wearing evenly and two of the holes, I assume are wear indicators, are still very visible. Does anyone know where I can find the inspection criteria for brake magnets? I have been to the Dexter site and magnets are not discussed other than the amperage they are to use. I have determined that mine are in good shape with about 50% wear on them but I would like to see the actual inspection criteria. To be sure since there are state inspecions required in many states there has to be a standard for pass fail.

[TomW]

Originally Posted by Tarheel

... The magnet on the new brake as a waffle pattern in the steel and 4 small holes in the ceramic magnet. ... My magnets are wearing evenly and two of the holes, I assume are wear indicators, are still very visible. Does anyone know where I can find the inspection criteria for brake magnets? ...[/FONT]

My round magnets' wear surface has three recessed holes where brass screws can be seen.

If the screws are getting close to the drum (same wear criteria as the shoes), its time for replacement.

Inland Andy says Round magnet good for 18,000 miles. Oval good for 20,000 miles.

Of course I paraphrased his response. But I think I got it right.

Tom

[markdoane]

This is what Reliable Axle has to say:

Electric Drum Brakes-Magnets

Your electric brakes are equipped with high quality electromagnets that are designed to provide the proper input force and friction characteristics. Your magnets should be inspected and replaced if worn unevenly or abnormally.

Even if wear is normal, the magnets should be replaced if any part of the magnet coil has become visible through the friction material facing of the magnet. It is also recommended that the drum armature surface be refaced when replacing magnets. Magnets should also be replaced in pairs (both side of an axle).


. . . that's all I can find.

[Tarheel]

There seems to be pleanty of material in the magnet, Oval magnets so no screws, no scored marks either to show wear.

[overlander63]

Rick, the following is from the Pennsylvania state inspection guidlines. Trailer brake magnets are not addressed:
7) Inspect the braking system. Remove at least one front and one opposite rear wheel and reject if one or more of the following apply:
(i) The hydraulic hoses or tubing leaks; is flattened, restricted, insecurely fastened or improperly retained; or has exposed cords.
(ii) The wheel cylinder leaks, has missing parts, is improperly retained or is not functioning.
(iii) The caliper leaks, has missing parts, is improperly retained or is not functioning.
(iv) The lining is broken; not firmly attached to shoe; or contaminated with oil, grease or another substance that would affect proper brake operation.
(v) There is mechanical damage other than wear.
(vi) The inside diameter of the drum is greater than maximum diameter stamped on drum or greater than .090 inch over original drum diameter for unmarked drums.
(vii) The disc thickness is less than minimum stamped on assembly or less than manufacturer's specifications.
(viii) The bonded linings are less than 2/32 inch at the thinnest point.
(ix) The riveted linings are less than 1/32 inch above rivet head at thinnest point.
(x) The drums or rotors are scored deeper than .015 inch.

[Tarheel]

I had the backing plate in my hand and took it to my mechanic that I trust. He assured me that they were in excellent condition. They have a gang of miles on them, but I think they look that good because of how much I use the exhaust brake. I don't usually apply trailer brakes until I am below 20 mph.

[TomW]

Originally Posted by Tarheel

... I don't usually apply trailer brakes until I am below 20 mph.

How do you do that? Do you not have an automatic trailer brake controller?

Tom
p.s. I read your post & thought of Lucy & Desi in The Long Long Trailer

[john hd]

Originally Posted by TomW

How do you do that? Do you not have an automatic trailer brake controller?

Tom
p.s. I read your post & thought of Lucy & Desi in The Long Long Trailer

exhaust brake.

john

[Tarheel]

I downshift at interstate speed and let the exhaust brake slow me down, it is very effective at slowing me down I come into the rest stops at 20 mph is 2nd or 3rd gear.

[BigAl]

Rick,
I can't remember where I read it but there was something posted about Dexter having a bad run of springs in their brakes. My trailer is a '94 and since I just got it third hand two years ago I installed new brakes and drums and complete backing plates just to be sure.
When I took them apart I found one wheel with the whole adjuster assembly rolling around in the drum. Obviously that brake didn't work.
So from your description of yours I would at least replace the adjuster springs.
Al
Ps: I changed everything while in the states since the parts were about half the price that I would have paid in Canada.
Al

[Tarheel]

You are correct Al, I inspected all of my brakes last spring, I had a faillure on the road with a broken spring on the star wheel adjuster. I found a broken spring an one adjuster that was frozen. I just finished pulling all 6 wheels and found one missing adjuster and yes the broken spring was the reason. Lets not forget that these are not self adjusting brakes, they must be manually adjusted. I think I am in good shape until next spring or till the next spring fails, I do carry spares.

[TomW]

Originally Posted by Tarheel

I downshift at interstate speed and let the exhaust brake slow me down, it is very effective at slowing me down I come into the rest stops at 20 mph is 2nd or 3rd gear.

I understand exhaust brakes.

My question is "Do you have an electric brake controlller for your trailer brakes?" My first read of your original post sounds like you do not. I do not have a Diesel engine as I prefer my gas-powered 454.

While Diesel engines have their advantages, I am curious how you can keep your trailer brakes from applying until you think you have reached the appropriate speed.

Tom

[wahoonc]

Originally Posted by TomW

I understand exhaust brakes.

My question is "Do you have an electric brake controlller for your trailer brakes?" My first read of your original post sounds like you do not. I do not have a Diesel engine as I prefer my gas-powered 454.

While Diesel engines have their advantages, I am curious how you can keep your trailer brakes from applying until you think you have reached the appropriate speed.

Tom

Tom,
He is using the exhaust brake only to slow down to a point then the "service" brakes. On diesels the exhaust brake works completely independent of the regular vehicle brakes. I know Tarheel, he isn't going to tow that beast of his without a brake controller. BTW an exhaust brake is on my short list of stuff for my truck. They are worth every penny...just wish the factory would install them.

Aaron

[Tarheel]

Arron I am still on my first set of brakes on the Dodge. I have 145k miles on it. The 454 will out pull my 92 Cummins as will everyother newer diesel inculding the 24 valve Cummins. I weight 16,600 lbs and get 13.5 mpg up and down I-95 from NC to FL the hills do knock me back to about 12.5. I took one trip without the exhaust brake and believe me coming down black mountain on I-40 heading east is hair raising without it. I very close friend and I have traveled literally thousands of miles together both of us in 34's, him with a 454 and me with my little 6 12valve Cummins. We both needed fuel at the sametime him with his 38 gallon tank and me with my 30. He has since bought a Powerstroke and I see his tail lights when we do serious climbing, like the Rockies at 11,000 ft. Its all a very personal matter and the new Mega Cab Dodge does tickle my fancy, but the price is not right. Yes I do have a brake controler a DrawTite Activator II. I haven't met the hill I couldn't climb, but I have met the intersection where I couldn't stop. Its not a good feeling.

[scottanlily]

Hey Tarheel ,

WHo cares who pases or beats you up the hill ,doesnt mean a thing.The cummins diesel is an excellent power plant .Very reliable.Those 6.0 powerstrokes have a ton of injector troubles ,the most common problem they have big$$$ to repair .Look for a new turbo at a 100k .Anyway the variable boost controller .little silver solenoid on the center of the turbo goes bad.The 24 valve cummins is awsome and again very reliable.

Scott