Jump to content

Disc brakes on the 5th?


oletimer

Recommended Posts

I know I must be the only one on this forum that's not so crazy about disc brakes on the trailer. When we ordered our new 2003 Teton we ordered disc brakes, and aluminum wheels. The day we were to leave the factory, they stopped us, and MADE us change to HD 3 3/8" drum brakes. A story behind that, but not for now. In the last 2 1/2 years I have been remodeling the Teton, and have spent more than the 2003 purchase. One upgrade was disc brakes. After about 16K miles, the pads were shot. My drum brakes had 75K miles on them and still had at least 50% shoe left.

I rebuilt the axels with SS pads USA bearings, but thought I would never put disc brakes on a trailer again. I kinda' laughed at an article in the last Escapees magazine when it was stated disc brakes stopped the camper in 25-50% less travel than drum. I think the author either had his gain set wrong, or was talking about electric mag brakes. I could slide my tires with the drum brakes, and I just don't see how you could do any better than that. BTW, while rebuilding my brakes, I visited a couple trailer manufactures who said they had more problems with disc brakes than drum. I know, I know less fade on long steep grades, and in the rain, but they do run hotter, as the pads are touching the rotor most of the time. OPPS, got SIDE TRACKED!! Back to my question. I have ordered a new 5th. I will still have air over hydraulic, but the only way Dexter offers HD drum is on 8K axels. I'm not sure what the Spacecraft will weigh, but our Teton weighs 18-19K, depending on how we load. The new 5th will have air ride, and Marsha knows what she is talking about, and thinks 7K axels would be enough, and might be a better ride, but no HD drums. I'm now wondering if I should give the disc brakes another try? The ones I had installed were not Dexter. I do have complete confidence in drum brakes, but do want the best ride I can get. Do Dexter disc brakes have backing plates to keep some of the salt spray, and muck away from the calipers? I seem to always over build, and I know in 1999 when I ordered our new Freightliner I got the axels too heavy, and the ride was always stiff in the truck, but I had an air hitch so that helped the 5th. Any open minded ideas?

 

 

Thanks, and I always value the comments, Dick T

 

Link to comment
Share on other sites

Even disk brakes need to be sized to the braking load needed. Single piston caliper brakes won't have the same stopping as opposed piston caliper units.

 

Properly adjusted, drum brakes deliver the same stopping power as disk brakes. Both can lock the wheel which is the maximum brake effort you can generate. The best is just before lockup.

 

Assuming proper sizing, the advantage of disk brakes is that they require no adjustments. Electric drum brakes need continual adjustment unless you know how to force the auto-adjusters to do their job.

 

Disk brakes clear themselves if they get wet and are far more resistant to brake fade than drum brakes.

Link to comment
Share on other sites

We have Dexter disc brakes and 8000 lb. axels on our Hitch Hiker. Before we left the house in mid May I checked the pads. With 24000 miles on them they still look like new. Our HH weighs about 16500 lbs. with about 3400 on the pin. I gota tell you coming down Wolf Creek Pass and La Veta Pass last month I'm glad I had disc brakes.

Link to comment
Share on other sites

Dick, one of your comments said that you always overbuild, and I wouldn't change that now with your axles! That is a great place to be overbuilt.

Dexter is also now building the 8K axles (for the last few years) with @ 1/2 walls instead of their older ones. All three of mine have been replaced.

With the air suspension, I think the ride is going to be much smoother on your fifth. It does somewhat "lumber" down the road and I've always wondered what the force is on all the suspension when the whole trailer is on the down stroke.

I've been running about 3 years now with my pads and they look great! The big secret is bleeding the system correctly.

Link to comment
Share on other sites

It is perhaps important to recognize that air suspension is wonderful for smoothing out 'primary ride'.

 

It does a great job of smoothing out major bumps and whoopsies.

 

It's not the best on the market for secondary. Probably better than leaf springs, but coil springs for sure, and arguably Rubber blocks in shear cope with minor imperfections much better. This is called 'secondary ride' and there is a wealth of information available.

 

Geo

Link to comment
Share on other sites

"... but they do run hotter, as the pads are touching the rotor most of the time ..." This could be the source of your premature wear. The pads should not touch the rotor at all when not applied.

And that is why correct bleeding of the system is so important. Any air and you've got expansion and pressure of the pads on the rotor.

Link to comment
Share on other sites

When we bought our trailer used, I had it in my head that I was going to upgrade from magnetic drums to discs as soon as I could. After a few trips out, and a couple stale green lights turning on me at 55 mph, I became convinced that the mag drums work just fine. They are adjusted correctly, I check em every time I am under there via the inspection holes, and once a year with each wheel in the air while I twiddle the adjuster. (they never seem to need any tightening)

 

If you still have your tandems on your truck, not having lost at least 1/3 of your service braking power, there is a good chance you will be satisfied with drums on the trailer.

 

Rich

Link to comment
Share on other sites

Dick, I'll give you my opinion. It is based on a large trailer in the 23K lb category. I assume any SC you build will be in that range. Unless you are building something tiny. Feel free to contact me directly if you wish.

 

You may be at the "rollover" point between 7 and 8K axles. IF you are building a 40' or larger trailer I'd at least consider the 8K axles. I'd trust Marsha and Wyatt, but you need to verify.

 

Personally, I'd NEVER have drum brakes again. They are simply too hard to maintain at a good braking capacity. Way too many things to go wrong in my opinion. I ONLY would put on the large Dexter discs. With a BluDot system you will be amazed at how well they work. I've had them on the last three trailers and they are pretty problem free. You WILL have to do dual BluDot actuators if you use the large Dexters, though. Too much fluid volume for the single actuator.

 

On the suspension issue, I WAY prefer the Mor/ryde IS for overall performance. The air is good, but I feel the IS is better. And less risk of issues. In MY experience. If you do end up with the air ride you might consider a combined air tank for both the brakes and suspension with proper protection valves. You can do dual tanks if you want, but I'd eliminate the compressor for the suspension since you have an air truck. But you HAVE to protect the brake system if you do that. No big deal to do.

 

My opinions only, but I've worked with these issues for years on many of my own - and customers - trailers.

Link to comment
Share on other sites

If you still think drum brakes are as good as disc brakes, here's a link to tractor brakes tests performed by DOT. 3-8% improvement in stopping distance of all discs over traditional s-cam drum brakes. Keep in mind that the the s-cam drum brakes are light years more sophisticated that mag drum brakes. Kind of like comparing the starship enterprise to the Nina, pinta or Santa Maria ships. Mag brakes are cheap dinosaur technology. Blue dot has antilock air over hydraulic controllers and Tuscon has antilock electric over hydraulic controllers. Can't do better than having anti lock on the trailer as well as the truck.

I have the sometimes problematic Kodiak discs on my trailer, but I think my problems were due mainly to my maintenance person's lack of detail working on my trailer. They are much cheaper than the Dexter's, but I would put on Dexter's when ordering a new trailer.

Link to comment
Share on other sites

Dexter does [or did] make a hybrid axle, 7k tubes ? and springs and 8k hubs with 12 1/4 x 3 3/8 shoes. I have them on my Keystone Cambridge. Alternately, you could use 8k axles and 7k springs. Being a redneck engineer, I see no downside to using 8k axles and 7k springs if you want a little better ride. Charlie

Link to comment
Share on other sites

Dick, one of your comments said that you always overbuild, and I wouldn't change that now with your axles! That is a great place to be overbuilt.

Dexter is also now building the 8K axles (for the last few years) with @ 1/2 walls instead of their older ones. All three of mine have been replaced.

With the air suspension, I think the ride is going to be much smoother on your fifth. It does somewhat "lumber" down the road and I've always wondered what the force is on all the suspension when the whole trailer is on the down stroke.

I've been running about 3 years now with my pads and they look great! The big secret is bleeding the system correctly.

 

Rocky,

Not sure what you mean by lumbering down the road, but I think I could take that for the smoother ride. When I upgraded to the disc, I kept bleeding the system over and over, thinking that was the problem. I now think, I might have had the wrong BluDot booster, but if I go with the disc this time it will be Dexter. I hate to bad mouth suppliers, so that's all I'll say on that issue.

"... but they do run hotter, as the pads are touching the rotor most of the time ..." This could be the source of your premature wear. The pads should not touch the rotor at all when not applied.

 

Dennis,

With drum brakes, the shoes are "pulled back" by the springs, I think with the pads, the pressure is just relieved. I know on smaller disc brake systems, if the rotor is warped, a little, the pressure just keep building.

Dick, I'll give you my opinion.

Personally, I'd NEVER have drum brakes again. They are simply too hard to maintain at a good braking capacity. Way too many things to go wrong in my opinion. I ONLY would put on the large Dexter discs. With a BluDot system you will be amazed at how well they work. I've had them on the last three trailers and they are pretty problem free. You WILL have to do dual BluDot actuators if you use the large Dexters, though. Too much fluid volume for the single actuator.

 

On the suspension issue, I WAY prefer the Mor/ryde IS for overall performance. The air is good, but I feel the IS is better. And less risk of issues. In MY experience. If you do end up with the air ride you might consider a combined air tank for both the brakes and suspension with proper protection valves. You can do dual tanks if you want, but I'd eliminate the compressor for the suspension since you have an air truck. But you HAVE to protect the brake system if you do that. No big deal to do.

 

My opinions only, but I've worked with these issues for years on many of my own - and customers - trailers.

Jack, Dennis, and Rocky,

I ALWAYS value opinions from everyone on this forum, even though it's "hard to be humble, when you're perfect in every way". :wub: I don't look in the mirror though.

Whenever I get a little cocky, Susan starts singing that song to ME.

In 2003, Teton could not install the IS system, but they could the RS(?) Mor/Ryde. We upgraded to the IS a couple years ago when we also changed to the disc brakes.

I couldn't see much difference in the ride or the stop.

Listen folks, I know disc brakes are state of the art, and has some advantages, but those drum brakes ain't bad, and I've never had the rust and corrosion with them like I have on the disc brakes. When I did my resent axel rebuild I installed SS pads, and USA bearings(kinda').

Jack, I might get in touch, and pick your brain before I make some final decisions. Thanks for that invite.

As always thanks for all the comments, Dick T

Link to comment
Share on other sites

Why go air to hyd to brake? Have Spacecraft put a commercial axle under it w/ full air & be done w/ it. Not to mention the Dexter stuff is their part$$$$ only whereas commercial axle is universal. Go with a 17" tire like moving vans.

That is a valid point. You certainly can do that, but I suspect there will be some "complications" with clearance and specs, etc. It would be an interesting project to follow. IF you decide to go that route I personally would only have confidence in Marsha and Wyatt doing it (Spacecraft). There are some very good commercial axle sets out there with air disc brakes and antilock. I looked at a bunch of them at MATS.They will not be cheap though. But If I ever build another 5er I'll likely pursue that path.

Link to comment
Share on other sites

 

Dennis,

With drum brakes, the shoes are "pulled back" by the springs, I think with the pads, the pressure is just relieved. I know on smaller disc brake systems, if the rotor is warped, a little, the pressure just keep building.

Jack, Dennis, and Rocky,

Dick T

With disc brakes, that square section sealing ring "rolls back" when pressure is released to move the pad away from the disc, ever so slightly. The size and section of that ring are very important to the proper release, and application, of the brake.

 

If the groove in the caliper gets crud in it to the point that the ring doesn't have the proper clearance to "roll", then you're right, the pad will drag. OR, if the wrong ring is installed, that too could cause drag, or ineffective braking.

 

All this being said, I'm talking strictly about hydraulically actuated discs. I have zero experience with air operated disc brakes.

Link to comment
Share on other sites

With disc brakes, that square section sealing ring "rolls back" when pressure is released to move the pad away from the disc, ever so slightly. The size and section of that ring are very important to the proper release, and application, of the brake.

 

If the groove in the caliper gets crud in it to the point that the ring doesn't have the proper clearance to "roll", then you're right, the pad will drag. OR, if the wrong ring is installed, that too could cause drag, or ineffective braking.

 

All this being said, I'm talking strictly about hydraulically actuated discs. I have zero experience with air operated disc brakes.

Rickeieio,

 

When I rebuilt all my calipers, I install all SS pistons, and new "O-rings". Did I miss something, because they were just O-rings? I do see what you mean, if there was a square part to the ring. Does all calipers have the option, because I ordered all the kits from the manufacture?

Dick T

Link to comment
Share on other sites

Disc brake pads should never "drag". They may touch the rotor surface but the assembly should never drag to the point of building heat the rotor is not dissapating.

 

My Dexter manual says to adjust their shoes till they just touch the drum but you can turn the wheel by hand.

 

My ideas binder has some notes about low profile air disc brake axles with 17.5 tires and ABS and be done with stupid controllers and wires and magnets and converting power supply to the brakes from air psi to electric to hydraulic etc etc.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
RVers Online University

campgroundviews.com

Our program provides accurate individual wheel weights for your RV, toad, and tow vehicle, and will help you trim the pounds if you need to.

RV Cable Grip

All the water you need...No matter where you go

Country Thunder Iowa

Nomad Internet

Rv Share

Dish For My RV.

RV Air.

Find out more or sign up for Escapees RV'ers Bootcamp.

Advertise your product or service here.

The Rvers- Now Streaming

RVTravel.com Logo



×
×
  • Create New...