self adjust brake owners

[TeJay]

Slaytop,
Thanks for the link to the Dexter self-adjusting brakes. I told you I needed to learn more even in retirement. That burnishing info I mentioned is what the DOT uses to certify vehicles for manufacturing. The testing is pretty tuff and they have to pass or back to the drawing board.

 

[slaytop]

I'm going to add one more site with more information. This says that the brakes adjust in both directions but they adjust tighter going in reverse than forward. If the brakes are placed in the wrong wheel position, that is, placing a left side unit on the right, they can over adjust and cause problems.

http://blog.easternmarine.com/dexter-nev-r-adjust-electric-trailer-brakes/

 

[Bob&Patty]

Tejay, as far as disc's go. The kits come with all the lines, rubber hoses, and an electric pump you mount in the coach. So the they are electric/hydraulic.

Gave some thought to bearing being bad. Well besides the obvious. Many years ago we used to see alot of "bernaled" bearings. It seemed that cars being tied down on trains and transport trucks would flatten the bearings. Then after a few miles they would get noisy and then come apart. I'm not sure if this would apply to RV's because they are either driven or pulled from the factory. The only exception would be the smaller trailers that are loaded on trailers or flat bed trucks to be delievered. The only thing that comes close to weight being appled to a stationary bearing would be the fact that when parked the trailer is moving in place when you are walking around in it. That would be loading the bearings in one spot for extended periods of time. If you get my drift. I think that now days we don't see much of that because most vehicles have either sealed front hub bearings (FWD) and rear sealed bearing. Don't see much wheel bearing greasing anymore. Just an ol' guys thoughts.

 

[TeJay]

Bob,
Dang I thought I had learned all I needed. Just kidding. I guess the idea of sitting weighted for long periods makes some sense. Vehicles being transported do sit and they get a lot of sideways movement. We're missing two important items. Heat is one for sure. Correct bearing affects heat. Also if they are loose then you get more sideways movement. I don't like the adjustment on the Lipperet axles. When I get back into them I'll change from a castle nut to the moveable cap. When I repacked my bearings I was not happy with the cotter pin placement. Remember the castle nuts that were either to loose or two tight? The pin needed to be put into the space between slots so we backed it off to the next loose slot. I spoke to a Bear alignment guy once. His fun job was to assist at the Indy 500 during the race month. He told me how they adjusted wheel bearings on those cars. Over tighten the nut with a socket and spin the wheel. This accomplished two things. First if for some reason the seal was not seated this would take care of it. The spinning distributed the grease. Next step was to back off the nut then tighten by hand while wiggling the wheel at either 12 or 6 o'clock until all perceptible movement was gone. That would give you a bearing clearance of between .003 - 005. That was the procedure I used for the next 32 years and I never had a bearing that I or my students worked on go bad.
The next item is the rockwell hardness and the depth of that hard surface on the bearings. Today's China bearings may not have quite the QC that Timken had. I don't know how much affect that rocking motion might have on a stationary China bearing. The bernaling you are referring to is the metal surface flaking away from being overheated or cracked. When inspecting bearings the first thing we looked at is the existing grease. If any sparkles were found the bearing were replaced. I know you know this but others may not. That sparkle is the first sign of failed or soon to fail bearings. As far as trailers sitting for long periods I just don't know. The military has those conditions sometimes. They have or used to have out of commission vehicles parked for long periods of time. They also used the best lubricant they could get, synthetic. I use synthetic, either Amzoil or Mobil 1 exclusively. I've had well connected individuals in the lub industry tell me that synthetic is the best. So why not use it??? I've also used Mobil 1 oil in everything I own or have ever owned and I've never had any engine failures. I no it is the best oil for all engines. I know of a trucking company that has some 18 wheelers that have gone 100,00 miles and up with only filter changes and keeping the oil full. That's a powerful statement.

TeJay

 

[Willym]

Bernaling - I think that you mean brinelling - damage caused by vibration on stationary bearings. It is actually false brinelling. Here`s a link with some info.

http://www.tec.nsk.com/Troubleshoot...ID=/DamageTypesAndCauses/FalseBrinelling.html

 

[TandT]

Here is a link to a Dexter ad that mentions how to break in the brake pads.

http://www.easternmarine.com/12-x-2-NEV-R-ADJUST-Electric-Brake-Assy-LH-6k-K23-458-00-0/

As mentioned in another thread I had all my brakes replaced after a totol brake failure.(cause unknown). The dealer never bothered to inform me about a break-in process. I have now driven the rig about 2000 miles since replacement.
Also, I would wonder if the transporters who deliver these units follow this process?

 

[TeJay]

Hi,
We would like to think that the delivery people take care of the units that they drive. That's in a perfect world. At least now you and those who have reads these threads are aware that there is a proper way to break in shoes and pads. If and when you have the occasion to have those shoes replaced again you can drive the unit carefully for those first 30-50 stops and that will take care of the break in procedure. The most important thing to remember is to not do hard panic type of stops during the break in time if possible.

Here's something else to file away for future reference. Most brake manufacturers make several different shoe replacements for each application. I am most familiar with NAPA parts (I don't work for them and never have). I dealt with them for 35 years during my automotive teaching career. My main reason was that they were a national chain and prided themselves on quality parts. They usually made 3 or 4 different qualities for each application. The prices for the different grades for the same application was usually was like $15-$22 for the cheapest up to $26 to maybe $35 for the best quality. I know pads are a lot more expensive now but you will never save much by going cheap. NAPA's best pad is called AE (I think). That stands for application engineered. It's meant to be a OEM replacement. Just check out a good dealer and ask them to explain the different grades of shoes or pads for a particular application. Their technology changes as needed and I retired 5 years ago so I may not be up to date. I have not checked yet to see if they can get some good shoes for our TT's Lippert axles. This fall I may look into that.
TeJay

 

[Bob&Patty]

Bill, been a long time since I was in school learning to spell. So sometimes I just wing it. No matter how it is spelled, thats what my instructor in college called it. Sorry Tejay...hope it was not you. Yes that was the "metalflake" grease that you would see. On some of the vehicles, if they did not have many miles on them you see the indentations on the bearing races. Sometimes you could peel the material off the rollers.

Tejay, I know exactly what you mean about not being able to get the proper torque (preload) on the bearing. The way the castle nuts are....at least to me. They are either too tight or too loose. So far I have not had any problems. I get the bearing set as tight as I can and then wiggle the wheel to see how loose the preload is. I'm not sure what you are refering to as a"removable cap". Got any info on those?? What ever happened to 2 holes being drilled in the spindle...12 o'clock and 3 o'clock. That seemed to work better. But what the heck do I know.

 

[TeJay]

Bob,
The little deal I was talking about was a pressed or stamped metal deal that fit over the hex adjusting nut on the axle. Around the outside were tabs with slot in them that were spaced different. Once the pre-load was set all you had to do was rotate the cover until the spaces lined up with the hole in the axle. Then you could put the cotter pin in but didn't have to rotate the adjusting nut. I think I started seeing them in the late 70's or early 80's. It was not something that ever broke so I never had to buy one, therefore I don't know what they are called. When I get into the axles later I'll take a nut off and head to NAPA and have them order 4 of those deal for for the TT. Maybe before I do that we can come up with a name to make the search easier. I'm becoming obsessed to find out what they are called. That's what retirement does for you. It's great.

That information concerning bearing wear was way more than I ever knew there was to know about bearings. I guess at the high school level I was doing good to get them to check the grease for metal flake to determine that the bearings needed replacing.

I can tell you what happened to not drilling two holes in the axle. The same thing that happened when they decided to not put grease fitting in tie rod ends or ball joints. It saves them a few cents.
Got to eat dinner.

TeJay

 

[TeJay]

Bob,
I did some research on the spindle cotter pin thing. My NAPA guy didn't know what they were called either. But the net came to the rescue. Type in, "Spindle nut kit," and you will see what I'm talking about. Dorman also has them available. I guess you have to order the kit (nut,washer& cap) to get the cap that I'm talking about but you can see pictures. I just may call Dorman and get a name.

TeJay

 

[Bob&Patty]

Thanks Tejay, I will look at them.

 

[TeJay]

Bob,
Here's a link to answer our questions. http://www.easternmarine.com/DEXTER-E-Z-Lube-Spindle-Nut-Kit-K71-622-00/
Tejay

 

[Willym]

Good info, thanks for the link.

Bob,
Here's a link to answer our questions. http://www.easternmarine.com/DEXTER-E-Z-Lube-Spindle-Nut-Kit-K71-622-00/
Tejay

 

[Willym]

I had 8000lb axles installed by Lippert back in April. They came with the 3.375" wide self adjusting brakes. Despite these features, I found the brake performance to be quite poor. I was told to back up several times to aid in brake adjustment, and did this several times before hitting the road. Braking performance did improve slightly, but I have had to run with my controller set at maximum gain. I also verified that all the magnets were OK. I did this by checking current and circuit resistance. Today I decided to check the brake adjustment myself.
On the Lippert self adjusting brakes there are two access ports on the brake backplate. (I expect that Dexter is similar, as much of Lippert's equipment seems to be similar to Dexter's) The two holes allow access to the ratchet wheel on the adjustment nut, and to the lever that operates the ratchet. Tightening these brakes up with an adjusting tool, or a screwdriver engaged in the ratchet teeth, is easy. The adjustment screw drive seems to have a much finer thread than on those manual adjust versions. However to loosen the adjustment you need two hands. One has to push the operating lever away from the ratchet using a thin bladed screwdriver, and another to turn the ratchet backwards with the adjusting tool.
Out of the four hubs on my trailer only one was properly set. The other three required significant adjustment, so I suspect that the self adjusting feature is not working on those three. I will monitor for any braking improvement as we travel to the Ontario Chapter Rally this Friday. Hopefully I shall be able to reduce my controller gain, as I find that running in the current arrangement results in the brakes grabbing at low speeds.

 

[TeJay]

Hi,
I don't know if this is what happened in your situation but my guess is that the shoes were not adjusted close when they were installed in April. I've worked on hundreds of drum brakes and also monitoring students who have completed brake repairs and if there is a way of screwing something up they will find it. This may be why only one self-adjuster was working. The self adjuster won't work if the shoes are not at least close to the rotating drum.
These brakes are called, "Self actuating." The shoe assembly will pivot on the anchor pin at the top and the bottom will move 1-1/2" to 2". When the shoes hit the rotating drum they are wedged against that drum and greater friction is created. The same action has to take place when backing up but the shoes have to contact the drum with enough force to wedge them against the drum When that happens the movement pulls up on the arm or cable and when released the spring pulls down and the shoes adjust out. If the shoes don't hit the drum with enough force to cause the wedging action then they don't shift and no adjusting takes place. If everything is working correctly when and only when sufficient movement or shifting takes place then adjusting occurs. I'll bet if you check them again they will be OK.
What would happen if you take both wheels apart and while cleaning parts reverse the star adjust wheels? The shoes will adjust in instead of out because the threads are left handed on one side. I've had kids do that.
Hope this helps.
TeJay