Self adjusting brakes - Mod

Self adjusters can over adjust if the brake drums are not running true. Dexter has a tolerance of .015" run-out which is too much.

You cannot compare the trailer forward adjusters with the automobile adjusters that required stopping in reverse.

js6343js6343 wrote:

donn0128 wrote:
Instead of sticking with 200 dollars worth of old school, bite the bullet andmgomfor disc brakes. Makes a huge difference.

Too late. Already installed.

I can't see the real advantage to disk brakes. I can easily lock up all 4 trailer wheels and at the same time in sequence. so disk brakes aren't going to increase stopping power. Maybe reduce fade, but frankly all I need the trailer brakes for is stopping. I have yet to have to use TV/Trailer brakes on downhill grades for more than a few seconds. TV exhaust brake controls speeds just fine.

Gdetrailer wrote:
That was when I bought new drums to convert from the old Dexter "star" rims to modern 5 bolt Ford pattern rims.

Did you replace the hubs, also?

I've found the biggest failure of brake assemblies has been either a buildup of dirt through open adjustment ports on the backing plate or no lubrication on moving parts when installing. I wish I had a dollar for every star wheel and threaded rod I've had to tear down and lubricate.

js6343js6343 wrote:
Could be I am anticipating the worst. I hope you are correct. One less problem.

Thanks

There should not be any "harm" in having them, self adjusting drum brakes HAVE been around for many years..

The downside is they sometimes fail to adjust, often times due to rust on the adjuster screw, brake dust/dirt build up on the adjuster screw, the adjuster wire rusting and breaking or the star wheel on the adjuster wearing out..

All of those above failure modes will never over tighten the brakes.

As far as overtightening, well lets just say it IS impossible for the automatic adjustment hardware to do so..

The adjuster screw can only move when no brakes are applied (IE no pressure against the drum. The adjuster cable has a spring to pull the adjuster down across the star wheel.

The spring only has enough strength to move the adjuster screw with no pressure against the drum.. It can only SNUG the screw.

Most likely the installer would have had to set the brake shoes too tight to have caused premature brake wear.

You only want to set the brakes so the drum slides on easy (IE very little to no drag).. If you set the shoes too tight you will have to force the drum on and that WILL ruin your brake shoes.

Nothing wrong with either way (IE auto or no auto), I just don't find it is worth the extra money for myself since I obviously am not hard on brakes.

Could be I am anticipating the worst. I hope you are correct. One less problem.

Thanks

westend wrote:
Yes. On some assemblies the adjustment lever can be bent or spacers used so it is moved out from the star wheel so it doesn't make contact. With some assemblies it may be possible to remove the adjusting cable and the adjusting lever entirely. It depends on how the assembly is built.

There is really nothing inherently wrong with the self-adjusting assembly. I don't know what has spooked you into changing them.

I recall seeing some posts that the OP started where several folks mentioned that the self adjusting managed to over adjust?

I personally think that those folks who made that claim did not initially adjust the brakes correctly.

I HAVE driven a lot of vehicles from the 1970s which had DRUMS on all four wheels, I can honestly say that I have NEVER, EVER encountered any such problem with drum brakes..

I have however encountered problems with the self adjusters FAILING to "adjust" as the brake shoes wore.. This would be noticed especially when it was the front drums as a pulling to one side or the other on the steering wheel..

There is no way self adjusters can over tighten, the design is simple, nothing more than a cable strung to a lever, the lever gets pulled slightly when the brakes expand..

The lever drops slightly when the brakes release.. The lever can only move the adjuster when it catches one of the "stars" on the adjuster wheel..

If the brakes are tight enough the adjuster lever will not catch a star and slide by it.

Not sure what folks are doing that they "need" to make so many adjustments on trailer brakes to warrant self adjusters.. I have adjusted mine ONCE in the now 10 yrs of ownership of my current trailer. That was when I bought new drums to convert from the old Dexter "star" rims to modern 5 bolt Ford pattern rims.

As far as I can tell, they ARE the original brakes on my trailer, not sure how many miles it has but it was bought in California and some how found it's way to PA.. My trailer is a 1984 vintage..

Just bought a new set of backing plates/brakes for it, will be putting them on in a couple of weeks. Bought standard non self adjusting, to me not worth the additional upcharge in cost..

The only reason for me to replace was last inspection the mechanic found some cracks in the lining at the bottom of one of the brake shoes.. Most likely will not pass inspection this year..

donn0128 wrote:
Instead of sticking with 200 dollars worth of old school, bite the bullet andmgomfor disc brakes. Makes a huge difference.

Too late. Already installed.

westend wrote:
Yes. On some assemblies the adjustment lever can be bent or spacers used so it is moved out from the star wheel so it doesn't make contact. With some assemblies it may be possible to remove the adjusting cable and the adjusting lever entirely. It depends on how the assembly is built.

There is really nothing inherently wrong with the self-adjusting assembly. I don't know what has spooked you into changing them.

I have seen several posts from individuals experiencing over tightening (based on imperfect hubs) and other similar issues. Also comments that they are more trouble than they are worth. Given the poor track record of my RV's quality control, I am bracing for another problem coming around the turn. Snake bit.

Instead of sticking with 200 dollars worth of old school, bite the bullet andmgomfor disc brakes. Makes a huge difference.

Yes. On some assemblies the adjustment lever can be bent or spacers used so it is moved out from the star wheel so it doesn't make contact. With some assemblies it may be possible to remove the adjusting cable and the adjusting lever entirely. It depends on how the assembly is built.

There is really nothing inherently wrong with the self-adjusting assembly. I don't know what has spooked you into changing them.