Caravan Disc Brakes

jimricho · Guru

Caravan Disc Brakes

Kelasi Biru · Newbie

Since retiring from full time work last year, my wife and I have started researching the purchase of a new caravan. We're leaning towards a tandem axle offroad van as we like the idea of free camping and expect to purchase a new unit later this year. I'm puzzled about the apparently low usage of disc brakes, especially when it comes to the offroad style of vans. You'd be struggling to find a new car these days which is not fitted with disc brakes. Also, as a long time trailer boat fisherman, I have to submerse my trailer for launching and retrieving and I'd hate to think of the maintenance issues if using drum brakes, especially for sal****er exposure. If it is accepted that offroad vans could well be subjected to river crossings etc, it surprises me that more offroad caravan manufacturers don't fit their vans with disc brakes. Do date, I've only found one manufacturer (Spinifex) which offers disc brakes as an optional extra, with associated additional cost. Have spoken with my Dad, a long time caravanner now in his '80's and he also is unsure why so few vans are fitted with disc brakes. Would appreciate any feedback from experienced offroad van users.

Thanks and regards

Dave (aka Kelasi Biru, the name of our boat)

Landfall · Guru

In a word "COST" manufacturers do not make the best product, they make the cheapest product.

Ken

herbie · Guru

The Cost, like anything that's the crunch of it. We owned an off roader , before this van,Could not see any value in owning another one when we up dated. ..You will find the price of the off roader out weighs the value you get from it. Not just the braking system but all the inside appliances are the same as the on road vans....All that really is different is the price tag and a few build specs,but some of the roads in Aus are too rough to take them down.And if you only want to free camp ,the tracks into most of these places you could drive in owning a push bike.The days of just wondering off road where ever one liked to go are far gone. Every where you go now is almost governed by some goverment dept,so if it is say a National park they tell you were to camp/ park /drive, and because it most places are geared for user pay now most roads or tracks are ok to drive on by any mode of transport as it is revenue so all come all pay kind of thing.

wasn_me · Guru

Brakes are basically a device that creates friction . They consist of a rotating component & a stationary component. The larger the stationary component, the more friction can be created. These simple requirments make drum brakes effective with little force needed. (This is why older cars got away without boosters). Friction creates heat. lots of heat in the case of brakes. This is the down side to drum brakes. With heat, the drums expanded unevenly, the result being brake fade. Drum brakes are also difficult to cool. About the only way to cool them is stop using them.

Stone damage is a huge problem with disc brakes. I have read the reason disc brakes took so long to be fitted to the rear axles of cars, was that it took time to design effective stone guards that provided adequate ventilation for cooling, without stones thrown up by the front wheels, being able to cause damage to the discs. I'd imagine stones (thrown up by the tug) would be a major problem if discs were fitted to vans. As Jimricho pointed out, drum brakes,on a van, are applied by the rotating force of the wheel. It would be an expensive exercise to supply enough pressure to apply disc brakes on a van. Boosted hydraulics would be necessary. (Something else to fail.)

I think the manafactures have worked it out pretty well. 10 inch drums are suitable for up to 1450kg. Larger required after this, either 2 axles or 12 inch drums.

I'll stick with the drums. Keep it simple.

Cheers Pete

-- Edited by wasn_me on Wednesday 10th of April 2013 07:15:24 AM

-- Edited by wasn_me on Wednesday 10th of April 2013 07:17:02 AM

Baz421 · Guru

There is another thread in Techies forUm pages - HYDRAULIC BRAKES - here's the first post but after this things have gone a bit funny. ajdeleon aka Andrew (obviously a psuedonym) hasn't responded but he's on line here regularly.

I would guess it's gone badly by his non response as I've posted and mailed him to keep us up to date as promised.

Maybe read this thread to see how difficult it could be to fit after market discs if manufacturers wont fit them.

QUOTE FROM HYDRAULIC BRAKES THREAD...

Hi All,

Has anyone looked at this new Brake Commander controller\actuator for hydraulic brakes? Looks interesting, especially the wireless remote - no wiring needed in my new truck.

Here's their website link - www.brakecommander.com

Thanks, and looking forward to your feedback.

Andrew

END QUOTE

I'm not sure stones would be a problem as its easy to guard against them for a disc brake set up.

Food for thought. Chers Baz

-- Edited by Baz421 on Wednesday 10th of April 2013 11:24:48 AM

-- Edited by Baz421 on Wednesday 10th of April 2013 11:37:08 AM

Kelasi Biru · Newbie

Hi Folks

My sincere thanks to Landfall, Herbie, jimricho, wasn_me and Baz421 for your feedback.

Since my initial post, I've spoken with the manufacturer of my boat trailer and also to the Qld manufacturer which offers disc brakes as an option on offroad caravans. Learnings are as follows;

- there is no way a serious boat trailer manufacturer would contemplate using drum brakes. In my case, the boat trailer has tandem electric over hydraulic disc brakes; the most effective and trouble free configuration available I suspect,
- the Qld offroad caravan manufacturer offers a brake upgrade to discs as an optional extra, for a significant additional cost, but endorses the electric over hydraulic disc brake configuration as the best braking system with the minimum maintenance, albeit at extra cost. Advice received was that most caravan manufacturers use drum brakes to contain the cost,
- new caravan buyers have to make the call on whether electric drum brakes are a viable and reliable braking system, especially for offroad vans used for river crossings etc

Most caravanners would not subject their vans to really wet conditions (such as deep river crossings) under normal circumstances and also most caravanners drive at lower speeds. This being the case, conventional spring arrangements with drum brakes would be satisfactory and obviously are legal. As has been determined, upgrading to more sophisticated suspension and braking systems (if you are genuinely going to do lots of offroad towing) may be warranted, but it is going to cost you.

I now have a much clearer picture. Thanks again to respondents.

Regards Dave (aka Kelasi Biru)

Peter_n_Margaret · Guru

I don't know where some of the information that gets posted here comes from sometimes.

The OKA has disc brakes on all wheels. They are BIG, but other than that are nothing special. No special guards.

The vehicle was designed for serious off road touring.

The trailer weighs about 1.6T. It is fitted with over ride mechanical disc brakes. They don't cost a lot more than drums.

The pic is taken somewhere between Alice Springs and Marble Bar, on the way from Brisbane to the Kimberley.

08-05-13P Papunya to Kiwirrkurra 010cE2.jpg

Cheers,

Peter

Baz421 · Guru

Peter n Margaret

I think you have missed the point here to some extent,,, you said in previous post -

I don't know where some of the information that gets posted here comes from sometimes.

The OKA has disc brakes on all wheels. They are BIG, but other than that are nothing special. No special guards.

The vehicle was designed for serious off road touring.

But your axles are not tandem and are NOT 1 metre apart and capable of throwing rocks from the leading axle wheel into the rear brake assembly of the trailing axle. Vulnerable points are htdraulic hose and bleaders if electric over hydraulic is chosen, as has been mooted by some.

The trailer weighs about 1.6T. It is fitted with over ride mechanical disc brakes. They don't cost a lot more than drums.

Override brakes are generally regarded as the cheapest but is that what we are discussing???? I think not. Generally discs cost more than drums as you have to tailor the fitting to the application ie internal clearance to body work of a van where floor space is sometimes critical, not just have a simple backing plate and drum on the end of the axle. So it's not as simple as we think.

If you find someone who supplies discs cheaper than 10" drums let me know please as my brother in law is looking for good off raod van next year.

wasn_me · Guru

Peter_n_Margret Wrote

I don't know where some of the information that gets posted here comes from sometimes.

My information comes from 46 years working as a maintenance fitter in the automotive, heavy equipment, drilling & trucking industries. I also like to read any technical information in regards to on going maintenance & improvements I can get a hold of. During my work life I worked with design engineers from America to make field improvements to earthmoving equipment.

The OKA has disc brakes on all wheels. They are BIG, but other than that are nothing special. No special guards.

The vehicle was designed for serious off road touring.

The topic was about the possibilities of fitting disc brakes to a caravan being towed.

I don't believe there is a comparison between this topic & a dedicated off road vehicle.

The trailer weighs about 1.6T. It is fitted with over ride mechanical disc brakes. They don't cost a lot more than drums.

I towed a boat trailer with mechanical over ride disc brakes for about 8 years (no alternative when brakes are subject to salt water). I had to remove them regularly. Surface corrosion from the disc would build up on the pad making them ineffective. On 2 occassions I had to surface the disc & replace the pads due to stone damage on the disc. Despite this they worked well.

I just did a service on a van 12 months old & had done about 13000k. The front of the axle was totally sand blasted clean. There was some evidence of this on the brake backing plate. I have seen vans where the brake backing plate is totally sandblasted with dents from stones. I don't believe disc brakes could survive this situation without effective guarding.

Cheers Pete

Peter_n_Margaret · Guru

I don't usually bother to return to reinforce my views, but I will make a couple of points.

Driven front wheels on a big 4WD vehicle will throw a lot more more rocks than a rolling wheel on a caravan, and the rear disks are directly exposed to the stones from the opposite side front, not protected behind another tyre.
The rear discs of the OKA have never suffered stone damage, not withstanding more gravel roads than almost any caravan ever experiences and no guards on the rear disks at all.
Likewise on that trailer. There are no disc guards and no disc damage.

The method by which brakes are operated is of no consequence to the relative costs of discs and drums. If someone is charging significantly more for discs, they are doing so because they can, not because of the inherent manufacturing cost of the parts.

Cheers,
Peter

Baz421 · Guru

OK maybe I didn't explain myself clearly in regard to disc brake costs in CARAVANS, ie the subject - in my previous post. I'll take the hit for that.

If the production line manufacturer DOESN'T PURCHASE A CHASSIS THAT HAS SPACE FOR DISC BRAKES OR is generally not set up to BUILD THE BODY AROUND DISC BRAKES IN A CARAVAN, ie floor and wheel well panels/templates and changes plus any interior changes then the cost will be greater for discs than drums. I think this is obvious. PLEASE NOTE there is no room to fit discs to my chassis - take this as evidence.

HOWEVER, I believe that the cost of the disc assembly and hub is more expensive than drums due to the quality of the product.

Drum backing plates and shoes are simply pressed steel welded where required with cheap linings. Discs assemblies are cast bodies machined in several places with high quality steel rotors that cost $.

I think we should stick to comaring apples with apples, and try to provide relevant and objective advice to those who seek it.

Nuff said by me.