Beware of self adusting brakes

[Matthew]

Has anyone had issues with the self adjusting brakes on their 5er? I read the tech section about leaking grease seals compromising the brake system and decided to check the bearings and seals on my 2018 310.

I rolled underneath to look at the suspension first, and found a nut missing on the equilizer the bolt was half way out. Then I found no grease zerts on any of the shackle pins, ( the threaded holes were there just no zerts). These were easy fixes (one new nut and four zerts).

I then started pulling wheels off checking bearings and seals, no grease leaking out as there was very little grease on the bearings; however when I got to the driver side wheels the rear was so tight I could not rotate it to take the lug nuts off and had to back off the adjuster to get the drum off. The pads were down to metal on a trailer that I have only put 1800 miles on. The driver side front was also tight, but I got it off without backing the adjuster off, pads were not down to metal yet but close.

There is clearly a problem with the self adjusters on the driver side. I talked to the dealer and they idicated the bearings and brakes were checked after the trailer was delivered from the factory. If that is the case the brakes got worn to metal in 1800 miles.

[TucsonJim]

Matthew - I have heard of this condition on a few units. Does your rig have Lippert axles or Dexter axles?

Jim

[Matthew]

I think they are Lippert but am not sure, is there a stamp somewhere on the axle?

[Cate&Rob]

I think they are Lippert but am not sure, is there a stamp somewhere on the axle?

Matthew - There should be a label on the centre of the axle identifying manufacturer, build date, capacity and other manufacturing data.

Rob

[FT4NOW]

Are you sure the dealer is giving you the right story. It's atypical for a dealer to pull all the wheels and hubs on a new trailer unless you worked it into the deal ahead of time. When the hub is pulled, the seals should be replaced. LCI authorized this for each wheel with the grease issue, but if you have Dexter axles, it has nothing to do with LCI. Also, if the self adjusting brakes are not adjusted correctly at installation it could be the source of your problem. There is a method to the initial setup of self adjusting brakes to ensure they "self adjust". I also wonder if it's possible for the magnet to be the culprit, did it seem to be in the correct spot when you pulled the hub?

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[Matthew]

They are Lippert mfg. 6/8/17. I specificaly asked the dealer if the bearings and brakes were checked after the unit was delivered and I was told yes. The magnet looked to be in the same place when the hubs were pulled on all four hubs. Don't know how they set up self adjusters, but the fact that only one side was failing that may be the issue.

[gbkims]

I'd read of brake drum runout tolerance affecting self adjusting brakes. This was for Dexter self adjusting. I'd figure Lippert's work about the same way.
https://www.rv.net/forum/index.cfm/f...print/true.cfm
http://www.rv.net/forum/index.cfm/fu...d/27582115.cfm
Quote:
"The Dexter's are "forward or reverse" adjusting. Basically they work on the concept of when excess running clearance comes between the brake shoe and the drum ID, there is enough brake shoe travel that the pawl makes a click of the adjuster. That one click is not much movement, I think it was like a 7/16-20 fine thread on the adjuster so 1 click (5 to 10 deg rotation) may have been approx 0.001 to 0.002" adjustment. They want it that fine so you sneak up on the adjustment.

That said I did have 1 wheel give me a hard time and it was not the fault of the Dexter self adjuster. It was the fault of the darn brake drum run out of the original drums. Trailer wheels are not considered "precision" in any stretch of the imagination. Not that they cannot be, just it costs a fraction more time to make the same drum casting precision verse poor. With 0.028" TIR, (out of round) running of the drum surface to the wheel bearings, this issue will go unnoticed on manual adjust brakes but not self adjusters. When you adjust manually you hear a drag then nothing then a drag. The nothing is the run out (air space of out of round). Since you set them for the drag and they do not adjust, well they do not stop as good but they do not cause a major problem.

On self adjusters that much run-out can cause a problem. The shoes adjust up into that excess run out area and they get too tight. If your drums spin within 0.015", then they will work OK. Auto drums back in the day use to spin within 0.005" TIR or better and had the reverse adjust feature.

I know I may be more into the details of these things then the average RV'er, but they do work well when all the parts are right and I'll put more on when they wear out.

Good luck with yours. Lippert is now selling forward self adjusters too. I do not know if they make them or have someone else make them for them. They may or may not be the same as the Dexters. There is not a lot of parts difference between to make them self adjust.

Hope this helps and good luck

John"

[Matthew]

Sounds reasonable. They must not only be badly out of round, but they have a taper problem as the pads are only worn to metal on one side, the other half of the pad still has decent lining left.

[FT4NOW]

Since your under warranty, might be worthwhile to take pics and send them to Emily at LCI, she has been very helpful for GD owners. Explain the history and prior inspections as well to her. I would see if they can send you a new drum and backing assembly (It's 5 bolts and you don't have to mess with the brake springs). If you replace one side, make sure to replace the other side even if not needed. She will also need a picture of the axle tag.

Emily [email protected]


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[Cate&Rob]

gbkims - Great info! . . . and I would encourage anyone wanting to know even more to go to the first link with all the pictures. This is someone who has the tools and knowledge to really determine the root cause of the problem.

(Yet another excellent reason to consider an upgrade to disc brakes )

Rob