Disc Brakes for Campers?

[MichaelOverfield]

As I continue to research, attempt to justify, and have that proverbial argument with myself, I have found that the disc brake upgrade is about a $1000 over the cost of a complete drum brake replacement using kits. The labor difference I didn't consider because I will talk my wife into doing most of the work, lol. Of course I now have concerns about the TIPM on my 2006 seeing a difference in voltage and independently deciding to over-ride the system and shutting everything down. Is this possible? Do I need to wire directly to the batteries? Help!?

Also, a call to Keystone revealed that my Cougar High Country has 4400 lb. axles. Great! That's right, I'm back to my rant about manufacturers that use components that just barely make the grade (tires, wheels, axles, brakes, etc.). Fully loaded my camper grosses about 10,450 lbs. with a pin weight of 1,500 lbs. I hate to always depend on the design engineer who builds in that 20% or 30% safety factor to make allowances for the manufacturer who cuts corners. Something about product liability comes to mind. Am I being just a grumpy old engineer that spent 25 years reading specifications and doing design work?

- Ed

Knowing that, I'd second mwilson's comment, go with new axles, of the 6K variety, new brakes to go with, new springs. I think the only reason my OEM axles are able to work, is that I have the smallest lightest trailer in the series that was offered, otherwise I'd be going there too, they used 3500# axles on mine, and the sticker loaded weight of 5300# or so, but there were other floor plans much bigger and heavier on the same set of axles.. It is amazing they get away with this really.

One other tid bit, Al-Ko is no more, Dexter bought them out, including the production facilities, and I found my Al-Ko axles have identical parts to the Dexter 3500#, in fact they are now more Dexter that Al-Ko from my rebuild work..

 

[mwilson]

This project is beginning to get pretty involved and rather expensive. I called Dexter and was told that the 4400 lb. axle was specially made for the camper manufacturers. I can't find an electric over hydraulic disc conversion kit to fit that size axle, you have to upgrade which is definitely a good idea. Great Scot! It looks like there would be a tremendous market for the disc brakes if it were less aggravating, and it would be more economical if you didn't have to rebuild the whole running gear. Russell, you are correct. And, I suppose if an upgrade to a beefier suspension was offered, it might be viewed as an admission of inadequacy, not to mention that the electric drum brakes are on the cutting edge of technology for 1946.

- Ed

Ed,

Do you have 12" brakes??? If so (and they are the same axles that I had) you already have the bolt pattern for the 6,000 lb axle. It is possible......that's how I did what I did. I assume that you are looking at the Kodiak kit or something similar??



http://www.etrailer.com/Trailer-Brakes/Kodiak/K1HR526DS.html

 

[mwilson]

I did the opposite by doing the axle first and re-using the existing brakes, hubs, etc....You would be going the other way by using your current axles and changing the brakes. Then you could upgrade the axles at a later date.

The camper 4400 lb. axles share the spindles used on the 5200 and 6000 lb axles from what I remember, I researched the crap out of it before ordering two non-returnable axles. The 4400 lb axles just have a thinner walled 3" axle tube.

The difference is readily apparent when you pick up a naked 6,000 lb axle and then pick up the naked 4400 lb axle. It all becomes crystal clear at that point.

 

[GAmes]

In my case my 4400 lb axles had the 12" brakes along with the common bearing combo that will accept an 8 stud hub. All that I had to do was order and purchase the axles themselves. Came with the spring perches all welded on.
I can upgrade to 8 stud with a simple hub/drum change.

Same with mine, but 16X 6 (or 6.5 or 7) six lug wheels are easy to find.

Ed,
I think the axles on GAMES trailer are insufficient - much better, yes, clearly - but what happens when a tire goes flat and load shifts? I favor the approach of the axles being more than adequate PRIOR to consideration of the pin weight.

The thing that gets me is that this scrimping saves so little money. There is not that much of a price difference between a 4400 Dexter axles and 6000 Dexter axle. Why not at least give the customer an option?

I think you are overthinking the weight thing. If a tire goes flat it is still supporting some weight, and in the several blowouts I've encountered over the years the load hasn't ever shifted. When I change a flat I roll the good tire off the ground with a stack of boards which puts all the weight on 3 tires and the hitch. I think 5200 lb axles are plenty for the weight of my trailer. I haven't weighed it loaded, but I did weigh each axle a mile from the dealer. The fresh water tank (59 gallon capacity) , located over the axles had a lot of water in it, but I don't know if it was full. The front axle was 3650, the rear 3500, pin 1550. The two right tires had 3550 on them, leaving 3600 on the left side (where the slide is). When we loaded it up, nearly all the storage areas, inside and out, are located between the axles and the pin. My educated guess is we were at about 10,500 on the last trip, at least 2000 on the pin. If we load up another 1000 to GVWR 500 will be on the pin. That is still about a 700 pounds per axle cushion.

The cost of the disc brakes is more than I can justify. As was pointed out in a TDR article, it isn't the brakes that stop you anyway, it is the tires. I'm getting rid of the 15" Goodyear Marathons (load range D) and installing 16" Michelin LTX MS2s (load range E). Surprisingly, the Michelins are only rated for 140 lbs each more than the GMs. Since I have never had a tire failure with Michelins in over a million miles, I think they will do nicely.

The factories buy Lippert frames & axles by the train car load. The same frame goes under a 28 ft single slide as a 28 ft triple slide. To have frames with different axles attached increases costs. Very few trailers are ordered from the factory by customers. Dealers order trailers in bundles, the cheaper the better. Even if higher rated axles were offered, the dealers more than likely wouldn't order them because of the added costs, and the ignorance of the typical RV buyer.

 

[mwilson]

They also bank on 95% of the trailers being sold will go to an RV park or some other stationary condition.

It's the remaining 5% of us that get screwed by under-sized running gear when we really get out and use the things.

 

[GAmes]

Frankly, the axles don't concern me as much as Lippert frames do. This is our old Monaco 5er after about 12 years of ownership. It always had flex in the frame, but then the flex became so obvious a camper asked me about it after I had parked the rig in NY. I blew it off, and towed it home, by way of the Blue Ridge Parkway. The guy's remark nagged at me though, so I pulled the bottom panel that covered the hitch framework.

Two fore & aft beams.

No more flex.

 

[RUSSELL5000]

GAmes,

Would you recall the TDR article on stopping - I'd like to read. Appreciate it if you recall.


Your pictures of frame cracks are sobering (to say the least). I'll need to keep an eye out.


I am sure you guys are right in your analysis of the way the RV manufacturers are producing. I don't understand these issues near as well and so my inclination is to be very conservative. I sure feel better rolling down the road now than with the factory setup - especially 2,000 miles away.

Still, I am right in line with Ed's comment - a good set up in 1946. Is there a vehicle offered on the market with drum brakes today? A vehicle with no shocks on the suspension?

The bed in my trailer is hinged up to allow access to storage underneath - two pathetic little hinges with pathetic little screws. One hinge pulled out right away. Went and got a box of wood screws and a piano hinge - cost me about an hour and a half and $25. Would cost the manufacturer less, and I would have paid $25 more not to fiddle with when I bought the trailer. Irritating.

 

[GAmes]

There is no doubt that the materials & workmanship in most RVs is pitiful. I'm convinced that most of it is planned obsolescence. The brake article is page 96, issue 40. There are followups in issues 41, 50 & 51. As for drum brakes, most class 8 trucks still have drum brakes.

 

[crispyboy]

When I changed the axles on my Airstream trailer last summer I was tempted to go with the disk brakes but could not justify the extra expense. I was also concerned about the actuators. Several years ago Airstream put disk brakes on from the factory as an option. It didn't last long because of all the warranty work on the actuators. This didn't make me feel very reassured that I should spend this money.
Instead I went ahead and pulled new 12 ga brake wiring of equal lengths and put in a Pollock junction box in case I ever have to replace the umbilical cord or do some troubleshooting.
It took quite some time for the brakes to seat themselves but after and adjustment or two I am quite please in how it stops.
If I ever I get to the time in life where I can travel extensively I will highly consider changing to disk brakes. Right now our family can only do a few thousand miles a year so the drum brakes do good enough. Besides the exhaust brake on the old Dodge works quite well!

 

[Killgore]

I was looking at the Kodiak disc brakes as a possible replacement for the standard electric drum brakes. The tech with Dexter that I talked with said that it was a comparison of apples to oranges. Besides the basic disc verses drum efficiency, the hydraulic verses electric actuation (loss of magnetism due to heat and/or age) makes the disc so much more superior. Having the correct actuator brings in another variable, however, I would hope that today's technology has overcome some of these issues that were present in the past.

I was interested to see the progression of railroad braking technology as an unrelated comparison. George Westinghouse received a patent in 1868 for air-brakes on railroad trains. Remembering that at that time brakes were applied individually to rail cars by brakemen; a very dangerous and inefficient method of stopping a train. It took 25 years before air-brakes were required with passage of the Safety Appliance Act of 1893 primarily because railroad companies were resisting due to the expense.

Of course I'm not advocating any kind of legislation, but it would be nice if manufacturers would use the most modern technology verses letting the bean-counters run their organizations only looking at the bottom line on the P&L. I would hope that as more and more buyers become educated on the pros and cons of basic RV construction, that the manufacturers will view good engineering practices as a superior marketing tool rather than an added expense. Until that time I guess I better slow down while I save my money to make a conversion that shouldn't have been required in the first place.

Maybe I should be directing my discontent at the Lippert frame folks from what GAmes has posted? That is not only sorry workmanship but it also tells me that somebody doesn't have a Quality Control Department and needs to hire a better design engineer.

- Ed

 

[mwilson]

Just getting a visual of locking one of the grandkids (both boys so they would do it in a heartbeat) in the trailer with a 12 volt battery, two bare wires and a walkie-talkie.........and me yelling "Touch the terminals now!!!!!"......

I can see it........

 

[Killgore]

Mike, you're absolutely right! The engineer would blow the whistle and the brakemen would scamper up on the brake platform and start cranking.

Years ago, about 1956, I can remember watching the movie "The Great Locomotive Chase" starring Fess Parker. In the movie, in order to quickly stop the train, the engineer would throw the locomotive into reverse. I watched how Disney filmed the movie and they claimed it was one of their most dangerous productions; the General, running in reverse at 70 MPH, etc, etc. Incidentally, the General is now in a museum at Kennesaw Mountain Battlefield. It was in a court battle between the states of Tennessee, Georgia and the grandson of the conductor, Fuller, who all wanted to claim it. Georgia finally won out with even the State Troopers getting involved at one point on who was going to take possession.

- Ed

 

[Jim W]

Not that I want to start an argument but I always listen to what Harvey Barlow had to say and his opinion. I may not agree with it but I would listen. This was from a link in a thread call heavy towing back around in 2012.

These are Harvey's comments and I quote:

"The DPrew, you probably won't appreciate my opinion after spending a ton of money for hydraulic disc brakes but in my opinion those systems are more cost and more trouble than they are worth. Ordinary electric drum brakes work fine as long as the brakes and wiring are in good shape and you have a good brake controller (BrakeSmart or MaxBrake) in your truck.

The problem Wingate described above is typical because in order to create hydraulic line pressure a pump is required and as long as the driver's foot is on the brake pedal that hydraulic pump is churning fluid and overheating the fluid.

I pulled several trailers with disc brakes when I was transporting. I hated them because of the delay between truck brake application and trailer braking. I kept my finger on the manual slide on my BrakeSmart controller when pulling a heavy disc brake trailer on LA or Phoenix freeways during rush hours because the delay scared me."

End quote.

You may want to think about the delay issue that could come about with the use of electric over hydraulic braking system on a trailer.

Just another view point from the past.

Jim W.

 

[RUSSELL5000]

This has been good discussion. I had a conversion to disc brakes as the next item on my list. Clearly, more homework to do. I think I'll try to think on this some, read those previous articles in the TDR magazine, and see if I can't enunciate some pros and cons.

 

[Killgore]

Jim, you're probably right. I think I'll table my efforts, labeling them as too expensive for my budget, too many unresolved issues, and maybe trading one problem for another. (I do better discussing military history and the brakes on old steam engines.) I think if this discussion has resulted in any constructive thoughts it would have to do with "buyer beware", periodically inspect beyond the obvious, and exercise caution when on the road realizing that what we pull is not up to the standards of what we drive.

- Ed

 

[GAmes]

I've pulled several big boats that had electric/hydraulic brakes on the trailers. I've pulled some RVs with them too, but never could really tell much difference. Since boat trailers spend a portion of their lives under water, disc brakes are the best choice. I didn't hate them, and I think they are an improvement over drum brakes. Just not $1500 worth of improvement.

 

[AfterBurner]

My horse trailer came from the factory with kodiak discs. They are the cat's meow! While I can't do a before and after comparison with this trailer, I have pulled horse and utility trailers of similar weight and the drums can't hold a candle to discs. In 8 years and 70K miles, I've only had one problem... one caliper blew a seal and drained all the brake fluid. I was on the road, but kodiak is common enough that I was able to find a trailer shop that had a spare caliper.
I did have an issue with the OEM brake controller on my 2011. Despite the dealership's promises I found out that it wasn't programmed to handle EOH (installed maxbrake). That's not a problem on my 2014 as the OEM controller now has a setting for EOH.
After living with disc brakes so long, I get annoyed when pulling someone else's trailer with drums.

 

[GCroyle]

Sorry, didn't take the time to read all of the posts but I do have Dexter 4 piston disc brakes on my twin axle Airstream. While I admit I have worked on them a bit more than what should have been normal due to incorrect hoses and setting up capabilities for inboard bleeding. These are incredible stopping power brakes. Comments about rigs hauled that didn't have the owners touch and might not have been fully bled, I bet that's what leads to questionable reputations.

Disc brake delay normal, hogwash.

Here's my writeup and comments about disc brake lag and it includes a video.

http://www.airforums.com/forums/f439/disc-brake-lag-pressure-vs-time-96724.html

Gary

 

[Killgore]

Gary, an outstanding write-up!

 

[mwilson]

Outstanding Job Gary!!!

You are like the maestro of trailer disc brakes!!!

I am moved by the sheer power of your written word and I'm surprised that you even hang with us........:-laf