Replacing Brakes

[hotfishtacos]

Originally Posted by padlin

Tried breaking in the brakes per the Dexter manual, I can not get the brakes to lock up even with the controller on max. After slamming the brakes on @ 20mph about 30 times the truck brakes read 350 degrees, the drums on the trailer at 75!

Think I need to try manually adjusting them.

I'm taking it that if I pull the emergency they should apply instantly, as opposed to the 6 second delay I reported above. I'll give that a shot when I get it jacked back up, whenever I can get to it.

Bob, I am reporting what I found after my recent brake job. I also just converted to electric self-adjusting brakes for my 19. It included everything including brake backing plates, drums, bearings, races and seals and I did the work. I used heat-sealing marine crimp connectors to reconnect the brake electromagnets that were far better than the standard crimp connectors ETI originally used.

First I followed Dexter's recommendations for burnishing the brakes by taking it out and applying quick braking from 40 MPH to 20 MPH about 20 times. This is supposed to help the magnets and shoes start conforming to their mating surfaces. The trailer stops really fast when I set the brake control high but I also could not get my brakes to lock up. I did a couple of additional tests;
1. Pulled the pin on the emergency disconnect switch and measured the resulting current. With 4 magnets rated at 3.2 OHMs each and a trailer supply voltage of 13.1 volts DC I measured 16 AMPS, just what is expected.
2. I ran the dual axles up on ramps with one wheel set suspended at a time, put on the parking brake with the truck in park and maxed out the manual lever on the brake controller after spinning the wheels by hand. In all cases the wheels stopped spinning immediately.
This tells me the brakes are working as expected. I expect it to take some time for the brake drums and magnets to fully mate with their mating surfaces and the brakes to fully adjust but the trailer stops really fast when I set the brake control high.

I plan to take about a 6 week trip up the Eastern Sierras in California soon and will report any changes in braking performance.

[padlin]

Thanks, I'll be trying the manual brake test when I get back in town.

[cpaharley2008]

I think I will wait for disc brakes on trailer axles before making any changes,,,,,

[tdf-texas]

Originally Posted by cpaharley2008

I think I will wait for disc brakes on trailer axles before making any changes,,,,,

Funny you should say that....
I was just looking at a kit to convert to disk brakes.

https://www.etrailer.com/Trailer-Bra.../T4843700.html

[Brian B-P]

Originally Posted by cpaharley2008

I think I will wait for disc brakes on trailer axles before making any changes,,,,,

Originally Posted by tdf-texas

Funny you should say that....
I was just looking at a kit to convert to disk brakes.

https://www.etrailer.com/Trailer-Bra.../T4843700.html

Yes, disk brakes for light trailers have been available for a long time. They are only hydraulic, so they are most popular in surge systems (which are hydraulic anyway), but electric-to-hydraulic converters (which take the signal from the controller in the tow vehicle and apply hydraulic pressure to the brakes) are readily available. The problem is cost, since the converter is typically more expensive than every other brake component put together. They are very rarely used on small travel trailers, but are sometimes found on large fifth-wheels, and occasionally on boat trailers.

It would be possible to operate the caliper for a disk brake with an electric motor directly, but that is not commercially available except as a parking-only feature for cars.

[John in Santa Cruz]

maybe we need AIR BRAKES like the big rigs use!!!! ;-D

[Brian B-P]

Originally Posted by John in Santa Cruz

maybe we need AIR BRAKES like the big rigs use!!!! ;-D

At least you can get those as disks.

Some large diesel motorhomes have had air brakes, which can be interesting for driver licensing, as an air brake endorsement is usually required, and only heavy truck and bus drivers typically have that.

[John in Santa Cruz]

Originally Posted by Brian B-P

At least you can get those as disks.

Some large diesel motorhomes have had air brakes, which can be interesting for driver licensing, as an air brake endorsement is usually required, and only heavy truck and bus drivers typically have that.

yeah, my kid had to get a class B w/ airbrake endorsement to drive his M925A1 5 ton Army 6x6... Said the test was easy-peasey (in Reno). The driving test inspector was this tiny little grandmotherly classic 'little old lady', but she was a real trooper, climbed up into the cab, he handed her one of his tank commander headsets because otherwise you can't hear each other over the 14L cummins, and she went through the test, and was actually smiling at the end.







btw, it has drums... really really big drums. his 22000 lb payload army trailer ("Heavy Expanded Mobility Ammunition Trailer", M989A1) also has drums.

[hotfishtacos]

I just got back from a short 900 mile trip up the Eastern Sierras and back from sea level to 7,000 ft and the new self-adjusting brakes wore in during the trip. I had to back off the brake setting several times when I noticed the trailer braking increasing. I believe the brakes surfaces are now seated and the brakes forces will be repeatable over time. I also used an infrared heat sensor to monitor wheel temps during the trip and saw no anomalies. So far I am pleased with their performance and glad I made the conversion to self-adjusting brakes. I don't plan to do any maintenance on the brakes or bearings for maybe 4 or 5 years...unless I see or hear something unusual...

Steve

[MyronL]

Wow, John, whatta picture! Living large!