What's wrong with disc brakes?

[NevadaGeo]

Originally Posted by Dspchef

I replaced both axles on my 76 Excella 500 2 years ago. I ordered mine through High Sky RV Parts and had a great experience using them. I know they have gotten a bad rep previously. Anyway, I just gave them the model of the trailer and they took care of everything else. Our unit had the old disc brakes that were no longer usable, and I ordered the EZ Lube axles with 12" electric brakes. I also ordered a lift kit. Axles took about 6 weeks to be delivered to the closest Redneck Trailer Supply dealer that was in Lincolnton, NC. Just a 3 hour drive for me. Here is my YouTube video on my axles and install.

I'm curious, I've seen several times where folks say the disc brakes were not usable or something like that. Is there some type of team out there that is being paid for people to put 100 year old drum brake technology on your airstream instead of modern disc brakes?

[Dspchef]

Originally Posted by NevadaGeo

I'm curious, I've seen several times where folks say the disc brakes were not usable or something like that. Is there some type of team out there that is being paid for people to put 100 year old drum brake technology on your airstream instead of modern disc brakes?

Well, if you have the disposable income that can afford the newest disc brake technology, then by all means go for it! I have a family that wants to camp in a safe, usable unit. I went with the electric brakes. I am not aware of any cabal for pushing electric brakes, but then again, I am not paid spokesperson for Raybestos or any other brake shoe manufacturer. I guess every thread or group has “that guy” who…..lol!

[richard5933]

Originally Posted by NevadaGeo

I'm curious, I've seen several times where folks say the disc brakes were not usable or something like that. Is there some type of team out there that is being paid for people to put 100 year old drum brake technology on your airstream instead of modern disc brakes?

I think there are a number of reasons for going with electric drum brakes. A big one is the wide availability of parts and service across the country for the electric. Another would be the complexity of installing disc brakes vs electric, especially on a trailer that has not had disc brakes previously.

For many people the increased performance of the disc brakes is not worth the effort since their drum brakes are doing the job at hand.

[4RXLA]

Airstream offered vacuum/hydraulic disc brakes as an option on top line models in the 70s-early 80s. The brakes were made by Ausco and there was a thread not too long ago from mindheavy who said they contacted Ausco and ordered replacement calipers and other parts. What makes these brake systems unusable is the vacuum/hydraulic actuator which is no longer available and not compatible with modern auto anti/lock braking systems. The old actuator ran off of tow vehicle engine vacuum and a hose needed to be installed on the tow vehicle to a vacuum booster. These Ausco brake systems can be converted to electric/hydraulic by purchasing a 1600 psi actuator.

In the 90s-early 2000s Airstream again offered modern disc brakes with an Actibrake electric/hydraulic actuator. The Actibrake actuator was recalled and needed to be replaced and there were issues with the brake lines kinking and being too short causing wheel lock while traveling.

Both the Ausco and more recent disc brake systems work great when they work, but are problematic when they fail while on a trip in the middle of nowhere with limited parts availability or a mechanic willing to touch the system, especially the actuator. This is why most owners replace them with drum brakes especially when replacing the axles. I still use the Ausco brakes on my 77 with a Hydrastar electric/hydraulic actuator purchased in 2011 and they work great. I have collected replacement calipers, pads and rotors and cart them with me on trips in case I have a problem. If my actuator were to fail while on the road, I would be dead in the water until I can replace it. Drums are more convenient and can be repaired by anyone anywhere.

[Action]

Hundred year old drum brake design works well because of many reasons.
They are reliable, easy to modulate pressure for different braking, they do the job, they are cheaper than disc and parts are very easy to find for repairs.

Disc brakes are superior in stopping a vehicle. No question.
However, on a trailer, it is applying the brakes that becomes the issue. It becomes complex which makes it costly and less reliable. Parts are not common and techs that know how those brakes work are not plentiful.

The only way disc brakes will make it into the trailer market is if the trailer industry jumps into that in a big way bringing down the cost and making it common place. Otherwise disc brakes will be a feature on high end trailers. And drum brakes will be the common choice among new trailer builders, mostly because they do the job and are less money. The consumer demand for lower cost trailers versus newer/better/more costly technology has always been slanted towards cost.

Action

[kb0zke]

Interesting discussion! A friend of ours has a 2010 high-end fifth wheel with the standard Kodiak disc brakes. No problems in the 12 years he has owned it. Back in 2011 we owned a Heartland mpg travel trailer as a "learner" while we considered full-time rv'ing. It had electric drum brakes and required a couple of visits to the dealer to get them set properly. They would either lock up at the first application of brakes or not do much of anything unless the tow vehicle's brakes were locked up.


We're looking at Airstreams from the early 2000's, 30-34 foot models, so they may be in need of new running gear in the near future. I had planned to replace the axles with disc brakes when that time comes, but maybe that isn't necessary.

[10Smiles]

We have a 2005 30 foot Classic. I think I am going to upgrade to disc brakes when we get new axles. The drum brakes seem to work fine, but I am pretty careful with them.

[Thiss]

Big disc brakes on the TV with added engine braking options is much more cost effective and where I would sink my money.

I would rather have the trailer brakes as a backups and just there to keep everything in a straight line. The electric drums are more than enough for these lighter trailers.

[Sylvain]

Some older, larger, more expensive models came with disc brakes as it was the case for my 79 excella 500. I think the main reason I have seen for people sticking with drum brakes is the cost. They are cheaper to buy and the electric conversion is also much cheaper. As stated by someone before, the models that had disc brakes were using vacuum which is a pain more difficult to connect with new vehicle. Disc brakes are more expensive to buy, but definitively easier to maintain (in my opinion), however as state by someone before they will require electric over hydraulic actuator, that are about $1000 if I recall.
I personally stay with discs and actually went for bigger ones one my rebuild. I have driven heavy trailers with tractors during harvest season and really saw a difference between trailers that had smaller brakes and those that had enough brakes on the trailer to stop it by itself. That's why I went for bigger ones.

[4RXLA]

Back in the 70s most cars still had drum brakes and most cars could tow a trailer, so the vacuum/hydraulic Excella-Vac disc brakes were really promoted for safety. I remember as a kid the Airstream dealer promoting them and watching a short film in the dealership. The original tow vehicle for my Airstream was a 1975 Cadillac coupe de ville that had front disc and rear drum brakes. Towing with the Cadillac was never easy given the huge length of the car and soft suspension.

[ROBERT CROSS]

KISS..
If it ain't broke, fix it 'til it is.

Bob
🇺🇸

[Wazbro]

Originally Posted by 10Smiles

We have a 2005 30 foot Classic. I think I am going to upgrade to disc brakes when we get new axles. The drum brakes seem to work fine, but I am pretty careful with them.

The first thing to buy if your going to disc brakes is the electric over hydraulic actuator. Just to make sure you can get one. There have been a couple threads lately on people having trouble finding them.

[Boxite]

Hydrastar or Kodiak systems are readily available from eTrailer… and are good systems…. But to answer your question as to “what’s wrong with disc brakes?”…. In my opinion the main thing wrong with them is price.

Otherwise I think they’re good conversion.

Here’s a good overview article about the subject and answers the question “Is a disc brake conversion for you?”

https://www.etrailer.com/faq-drum-vs-disc-brakes.aspx

[Coopdejour]

Originally Posted by ROBERT CROSS

KISS..
If it ain't broke, fix it 'til it is.

Bob
🇺🇸

Love it!
Mr. Cross,
Can always count on you to bring an issue to its lowest denominator!
Right to the point.

[hairyclive]

Originally Posted by 4RXLA

Airstream offered vacuum/hydraulic disc brakes as an option on top line models in the 70s-early 80s. The brakes were made by Ausco and there was a thread not too long ago from mindheavy who said they contacted Ausco and ordered replacement calipers and other parts. What makes these brake systems unusable is the vacuum/hydraulic actuator which is no longer available and not compatible with modern auto anti/lock braking systems. The old actuator ran off of tow vehicle engine vacuum and a hose needed to be installed on the tow vehicle to a vacuum booster. These Ausco brake systems can be converted to electric/hydraulic by purchasing a 1600 psi actuator.

In the 90s-early 2000s Airstream again offered modern disc brakes with an Actibrake electric/hydraulic actuator. The Actibrake actuator was recalled and needed to be replaced and there were issues with the brake lines kinking and being too short causing wheel lock while traveling.

Both the Ausco and more recent disc brake systems work great when they work, but are problematic when they fail while on a trip in the middle of nowhere with limited parts availability or a mechanic willing to touch the system, especially the actuator. This is why most owners replace them with drum brakes especially when replacing the axles. I still use the Ausco brakes on my 77 with a Hydrastar electric/hydraulic actuator purchased in 2011 and they work great. I have collected replacement calipers, pads and rotors and cart them with me on trips in case I have a problem. If my actuator were to fail while on the road, I would be dead in the water until I can replace it. Drums are more convenient and can be repaired by anyone anywhere.

There should be some sort of electric or wheel powered vacuum pump out there that would make the old vacuum powered systems usable for a decent price if someone looked around in the industrial catalogs for a low pressure vacuum pump (most older cars produced less than 15" of manifold vacuum at idle and many large engine less than that under heavy loads like towing).


https://www.gardnerdenver.com/en-ca/...f-vacuum-pumps

[Mollysdad]

People have converted from the drums to discs. They love them.
But it's usually people with larger trailers and fifth wheels.
The disc cylinder needs hydraulic pressure. Where's that coming from? A pump that's actuated by your brake controller.
It's a matter of complexity, running the hydraulic lines and a space to put the pump.
Lippert will be happy to convert drums to discs.

[Life is a Highway]

Disc work well. I doubt anyone would service them properly brake fluid is hydroscopic it absorbs moisture so as most trailers sit outside for extended periods brake fluid would have to be flushed every two years. Many never have their TV brake fluid flushed

Sometimes simple works better. If I had a zillion dollars I’d like a regeneration electric motor off our trailer wheels that would help with braking and charge house batteries.

[dznf0g]

Originally Posted by Life is a Highway

Disc work well. I doubt anyone would service them properly brake fluid is hydroscopic it absorbs moisture so as most trailers sit outside for extended periods brake fluid would have to be flushed every two years. Many never have their TV brake fluid flushed

Sometimes simple works better. If I had a zillion dollars I’d like a regeneration electric motor off our trailer wheels that would help with braking and charge house batteries.

I am one of those who does a fluid change every 2 years. I believe that is the reason my original actibrake actuator is still functioning properly. I love my disc brakes for a lot of reasons. I just wish someone would produce one with a pressure accumulator to cure that apply lag time while pressure builds.

[Al and Missy]

I was comfortable with electric drum brakes on my 6300# Safari. When I traded it for my 9100# Classic I felt the brakes were inadequate. Surprise - it had the same 4 2x12 brakes as my Safari. 50% more weight, same brakes, not a good idea.

I put on a Hydrastar actuator and ran the wiring and main hydraulic line myself. I had a mobile tech install the Kodiak calipers and their lines when he replaced the axles. My tests indicated that I had twice the braking power I had with the electric drums. The truck/trailer combo stops about the same as the truck alone.

https://www.airforums.com/forums/f43...ss-177345.html

In four years I have done nothing but change the pads, which are a standard automobile pad. When I replaced the axles I ordered EZ-Lube hubs. No need to disassemble drums to clean and inspect brakes or re-pack bearings.

Smaller trailer I might use electric drums, but maintenance is more difficult. Big two-axle trailer, I choose discs. Three axles, same as smaller as there is 50% more braking power.