Combining override and electric trailer brakes?

Submitted: Sunday, Oct 29, 2023 at 12:27
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Hi all. Has anyone heard of having override brakes and electric brake both being fitted and operational at the same time on a trailer/van? I have never looked into it and I have always believed you had either one or the other, however on another site, there is people claiming they have both fitted and “flip the lever over to disconnect the mechanical brakes and just use the electric brakes”. This statement frightened the hell out of me as I believe they are just disconnecting their mechanical brakes with the lever meant to be used for reversing and effectively driving around with no brakes! I’d like to think I’m wrong, but as I have never heard of both combined, I’m doing some fact finding. The posters are adamant they have both. Thought I’d start asking here however just like the other site, I realize there may be people that think they have both when in fact they may not. I was thinking it may be possible as it could use the handbrake cables for the override brake? I’ll be off to the trailer builder and parts supplier tomorrow to ask them.
Interesting to hear your thoughts. Cheers.
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Reply By: Nomadic Navara - Sunday, Oct 29, 2023 at 13:24

Sunday, Oct 29, 2023 at 13:24
Back in the 1990s when the smaller vans were equipped with mechanical brakes there were some companies who put override couplings onto vans with electric brakes. This attracted purchasers with existing vans to buy new vans and not have to worry about fitting a brake controller. They were promoted as an each-way operation. I did not hear of any problems doing that.

Override brake cables and the internals of the brake drum assemblies are much the same. The main difference between the two systems is the override coupling that interacts with the handbrake lever.

As far as your concerns regarding "flipping over the reverse lockout lever," there is no problem with that providing you have an efficient brake controller setup in your tug and it is adjusted to suit the van. You should do your checks when coupling the van to a tug without a brake controller to check the brakes will work every time you couple up - you may not have reset the leaver after the last time you reversed the van.


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Follow Up By: tonysmc - Sunday, Oct 29, 2023 at 13:57

Sunday, Oct 29, 2023 at 13:57
Thanks Peter, makes sense, I just wasn't sure the brake internals were compatible or it was done. They definitely don't need to attract purchasers now, so I wonder if they still do it.
My concern as to the lockout lever were more that it sounded like (or I read it that way) is that they fitted a controller to the car and flipped the lever and drove off thinking they now had electric brakes.
I do realise that you could upgrade to electric brakes on a van and just leave the same mechanical coupling in place and although redundant you could still use the handbrake component and save a little cost. If that was the case you may as well leave the lever flipped in place.
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Reply By: RMD - Sunday, Oct 29, 2023 at 13:52

Sunday, Oct 29, 2023 at 13:52
Tony
You have to be talking about twin axle vans for a start, because you cannot have electric brakes and override on the same axle/hub setup.
I am usure as to what you mean with the definite people you mention who claim to have both, that is unclear.
If you had one axle with override and the other with electric, the electric would largely negate the override when electric applied and also tend to reduce total braking ability. No doubt you can block out the mechanical system by a latch, but that still leaves you with only one axle doing the braking, Electric!
A bit nonsensical all round as they can't be operating as they are intended to with both trying to do the same thing. YES, the van may stop but the braking distance will be longer. Perhaps in depth multiple fine tuning of a combined system MAY operate ok. but who does that?
Cvans should be able to brake more than required for themselves AND provide some additional braking effort for the tow vehicle too, in an emergency. Overall the braking with the van should be better than normal.
I had an HJ61LC with a single axle van and with it attached the braking distance was better than the HJ61 alone. Tested in a real emergency.
Not many people actually go out and test stopping distances of their rig with van, or without, judged and measured with markers on the road for braking start and finish/stopping distance. Sort of guess work if you don't know how far your stopping distance really is.
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Follow Up By: tonysmc - Sunday, Oct 29, 2023 at 14:20

Sunday, Oct 29, 2023 at 14:20
RMD, I totally agree with you that it sounded nonsensical and that is why I posted and asked the question. Peter above says it was an option in the 90's so it seems it can be done.
My guess (and one person stated) is that they had override brakes and upgraded to electric brakes. One is adamant he has both systems operational.
A number of people said they flip the lever over so they are just using the electric brakes. My concern was, as I replied to Peter, was that they had an electric brake controller fitted to their car and think they are now operating with electric brakes. One stated " I flip the lever over to disengage the hydraulic brakes and just use the electric brakes" I'm hoping they have upgraded to electric brakes on the van too and just utilised the redundant mechanical coupling, but if they think the override brakes are still operational they may tow it with another car without the electric brake controller, so once again no brakes.
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Follow Up By: Nomadic Navara - Sunday, Oct 29, 2023 at 18:01

Sunday, Oct 29, 2023 at 18:01
Quote "Tony
You have to be talking about twin axle vans for a start, because you cannot have electric brakes and override on the same axle/hub setup."

RMD, go back and read my reply above. The dual system brakes were on single axle vans that were small enough to not require electrical braking. I have seen the vans for sale. They were produced in the late 1980s & 1990s during the period when manufacturers were transitioning from fitting mechanical brakes and fitting electric brakes to single axle vans. The system operated successfully and worked well.

If you fit the right handbrake lever and an override coupling to a van the handbrake function will work as an override brake system.


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Follow Up By: tonysmc - Sunday, Oct 29, 2023 at 18:46

Sunday, Oct 29, 2023 at 18:46
I went back to the site and looked up what vans they were talking about and it seems to be single axle.
I'll be dropping into the local trailer manufacturer, repairer and parts centre tomorrow and asking them. They've been in business for over 55 years, so I'll be interested what they say.
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Follow Up By: RMD - Sunday, Oct 29, 2023 at 19:35

Sunday, Oct 29, 2023 at 19:35
PeterD.
You didn't mention single axle at all, only "small".
Explain to all how the single axle had both types of braking system so we know what you mean. It is not clear.
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Follow Up By: Nomadic Navara - Sunday, Oct 29, 2023 at 21:08

Sunday, Oct 29, 2023 at 21:08
"I went back to the site and looked up what vans they were talking about "

Tony, what was that site? Can you please give us a link to it?
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Follow Up By: qldcamper - Monday, Oct 30, 2023 at 08:18

Monday, Oct 30, 2023 at 08:18
Mechanical over ride could be fitted to the hand brake mechanism if no hand brake is required but why? Maybe to give flexability of tow vehicles.
If on a duel axle with different types on different axles, it would be near impossible to know if it is adjusted correctly, how would the driver know what system is doing what, be forever flat spotting tyres.
We should be more worried about the future of caravan brakes, undoubtably computer controlled ALB and sway and stability control making them idiot proof but if the system fails will garantee the driver wont know how to control the van the first time a semi passes in the opposite direction.
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Follow Up By: Nomadic Navara - Monday, Oct 30, 2023 at 11:32

Monday, Oct 30, 2023 at 11:32
"Mechanical over ride could be fitted to the hand brake mechanism if no hand brake is required but why? "

What's this talk about 'if no hand brake is required?' The override coupling works on the handbrake mechanical system. The handbrake still works normally, as it does on override brakes without the electrical system in them.

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Follow Up By: qldcamper - Monday, Oct 30, 2023 at 16:44

Monday, Oct 30, 2023 at 16:44
Good point Peter.
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Reply By: Peter_n_Margaret - Sunday, Oct 29, 2023 at 17:57

Sunday, Oct 29, 2023 at 17:57
Here are the rules......
"15.2 All other trailers that do not exceed 4.5 tonnes ATM
These trailers must be fitted with an efficient brake system that complies with ADR 38/-. Except for over-run brakes, all brakes must be operable from the driver's seat of the towing vehicle.

For trailers up 2 tonnes GTM, an efficient braking system is considered to have brakes operating on the wheels of at least one axle. Over-run brakes may only be used on trailers that do not exceed 2 tonnes GTM.

Every trailer over 2 tonnes GTM must have brakes operating on all wheels. The brake system must cause immediate application of the trailer brakes in the event of the trailer becoming detached from the towing vehicle. Under these circumstances, the brakes must remain applied for at least 15 minutes.

All flexible hydraulic brake hoses, air or vacuum brake tubing and air and vacuum flexible hoses must conform to SAA, SAE, BS, JIS, DIN, ISO or ECE Standards and be fitted to the vehicle in a way that will prevent chafing, kinking or other mechanical damage under normal motion of the parts to which they are attached.

(For further information, refer to ADR 38/02 clause 5)

Note
Manufacturers should consider the merits of including a parking brake function when designing the braking system. ADR 38/03 clause 8 and 14 provides guidance for parking brake systems."
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Follow Up By: Nomadic Navara - Sunday, Oct 29, 2023 at 18:06

Sunday, Oct 29, 2023 at 18:06
Peter, the vans I am talking about were all below 2 tonnes GTM and were fully compliant when operating with their override brakes alone.


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Follow Up By: tonysmc - Sunday, Oct 29, 2023 at 18:28

Sunday, Oct 29, 2023 at 18:28
Hi Peter, thank for the reply. I'm aware of what the rules and regulations are and my post wasn't about braking requirements, It was more about if anyone can confirm electric brakes and override brakes could be connected at the same time? There seems to be a number of people out there that say that's what they have, I didn't believe you could do this. Obviously what I was asking would only apply to trailers/van under 2 tonnes.
Here is a couple of cut and paste of what was said; Quote " if you push the clip across the space it stops the hydraulic brake working when you use your electric brakes. " also "has mechanical override brakes but has been fitted with electric brakes as well. I flip a little lever to disable the mechanical brakes as we have an electric brake controller in the car. Either braking system should be legal but I don't believe it is a good idea to have both working at once."
For me those 2 statements raised a few questions, there was a couple of others similar. RMD mentioned maybe? on dual axle but these are single axle vans. I was thinking there is some people driving around with disconnected over-run brakes thinking they have electric brakes when they don't.
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Follow Up By: Nomadic Navara - Sunday, Oct 29, 2023 at 19:28

Sunday, Oct 29, 2023 at 19:28
"I was thinking there is some people driving around with disconnected over-run brakes thinking they have electric brakes when they don't. "

Probably far fewer people doing that than those with override brakes who have flipped the lock over to reverse park their vans and then driving off later without flipping it back. That was very common in the days of mechanical and hydraulic override brakes brakes.

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Reply By: RMD - Sunday, Oct 29, 2023 at 19:42

Sunday, Oct 29, 2023 at 19:42
If you actually had both systems, ie, override and electric on dual axles, you definitely want the electric on the front axle and NOT on the rear axle.
I still would like to know how electric, ie, magnet actuated can be also with a mechanical override. Which is hydraulic initiated. They are different in many aspects.
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Follow Up By: Nomadic Navara - Sunday, Oct 29, 2023 at 21:00

Sunday, Oct 29, 2023 at 21:00
RMD, the ends of the brake shoes in the electric brakes are pulled up on two supports by the springs holding them together. One end rests on the brake adjuster. The other end rests in an expander which is part of the handbrake mechanism. That expander pushes the ends of the brake shoes apart when you pull on the handbrake cables. The handbrake cables are pulled by the handbrake lever. If you have mechanical brakes on your van, the handbrake lever is operated by the override coupling pushing on it. It does not matter whether the handbrake lever is operated by hand when parked or the override coupling when the van is in motion, the brake shoes are activated in the same manner. In either case they stop or retard the motion of the van in the same manner.

My one reference to hydraulic override brakes was in reference to the reverse lock on the override coupling being forgotten after it has been activated to reverse the van onto site. If that oversight is not picked up and corrected at the time of driving off, the brakes on either the mechanical or hydraulic system will remain inoperative for the whole journey. (If you previously had not noticed it, the same override coupling is used on both the mechanical and the hydraulic brakes.)

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Follow Up By: RMD - Monday, Oct 30, 2023 at 07:54

Monday, Oct 30, 2023 at 07:54
Peter D

What you describe, style of brake system, is exactly what my van has as a braking system, and most do, but it isn't mechanically activated by anything during travel.
Trying to apply brakes mechanically via a cable, ie, using handbrake system is hardly a braking system for road usage, and shouldn't be considered the same ability either. Maybe it may work to some extent but the inherent friction and leverage of operation is lacking, much the same a Model T Fraud which were super effective as we all know.
The above you describe is electric bakes or maybe some mechanical brake if it operates to some degree. I presume it died out very quickly. you are the only person I know to report of one.
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Follow Up By: tonysmc - Monday, Oct 30, 2023 at 11:31

Monday, Oct 30, 2023 at 11:31
Many boat trailers have mechanical cable only overrun brakes fitted, as does my 2 tonne rated trailer. The reason for this is there is very little moving parts and very simple and most parts are exposed so easier to wash/hose down. For something being dunked in salt water all the time, simple cable, override, disc brakes work great.
RMD, I agree that if dual axles, brakes should be on the front axle and I was under the impression that it was a regulation that with dual axles the brakes had to be on the front axle or both axles, however never on the rear alone. Tried to find it but cannot find anything that actually says that, so maybe not a regulation but common sense. Only that over 2 tonnes to have brakes on both axles.
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Follow Up By: Nomadic Navara - Monday, Oct 30, 2023 at 13:51

Monday, Oct 30, 2023 at 13:51
Tony, None of the older copies of VSB1 that I have on hand specified which axle on dual axle vans has to carry the pair of brakes. If these documents do not specifically mention which axle the brakes were to be fitted then either axle is acceptable.

We were talking about the late 80s and early 90s period when small vans were under 16' overall body length (the fictional internal length had not been invented then.) The small vans were mostly single axle models, dual axle trailers in that range were special vehicles for carrying heavy loads, caravans supposedly carried less than 300 kg of load. 16' vans were sometimes single axle, sometimes dual axle, that was the crossover size. Single axle vans over 16' were extremely rare, the rest were all multi axle vans. As well, almost none had non load sharing axles. I don't think it matters much which axle of a load sharing suspension should carry the brakes. (As an aside, in those years, many vans over 20' were tri-axle models.)

I also don't think that 'common sense' cane into the equation of which axle to fit the one pair of brakes on either. It was simply a case of it is easier to run the handbrake cables to the nearest axle.

With that in mind, I am also at a loss as to whether I should have to had to specified whether I was talking to specify whether I was talking about one or two axles, I did specify I was talking about small vans. I was talking about 30 years ago, not modern times. I was also talking about the time when mechanical van brakes were all the go and it was the period where expensive electric brakes were being fitted to small vans. You don't have to go back many years before that when most power brakes on vans were vacuum operated and not electrically operated.


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Follow Up By: Nomadic Navara - Monday, Oct 30, 2023 at 18:47

Monday, Oct 30, 2023 at 18:47
"The above you describe is electric bakes or maybe some mechanical brake if it operates to some degree. I presume it died out very quickly. you are the only person I know to report of one."

RMD, you never give up do you. You just keep up having to justify yourself even when you are out of your depth, don't you. Firstly about me being the only person 'to report one.' Well the OP raised the subject so he must have known about them (and there was a third person who has heard about then that replied just after you reply above.) The vans were produced 30 years or so ago so there are not many people on the forum who were active around caravan that far back. The vans were not mainstream, their production was not for very long and there were not too many of them produced. In addition, I don't remember this being discussed online before. Most of the discussion I would have seen would have been in Q & A with Tom Olthoff in Caravan World. Have you heard of either of those?

Mechanical brakes were considered OK in their day. After all, they were produced when many of the the tugs had mechanical brakes. The only alternative back then was vacuum brakes similar to the ones used on semitrailers. When I first started towing vans there were no electric brakes. The only automotive electronics were the steam-driven valve radios. There were no electric brake controllers around until transistors developed that would handle the power required. The round trailer plugs only had 6 pins, not 7.

I retreated from vanning in the 1970s so I am unsure when electric brake controllers arrived but when I regained interest in the 80s they were around but they were very expensive and crude. The proportional controllers came in way after the first controllers did. At that stage electric brakes were a little better than mechanical brakes but their main advantage was the thumb control brake override.

In 1988 I regained interest and started hunting around and we got our van in 1990. At that time, most of the large vans had progressed to electric brakes but the smaller ones were still being produced with mechanical brakes. My Nipper had mechanical brakes and at the time I was not concerned about that. A couple or years on I commenced looking at new vans, that's when I noted the dual system brakes. When I eventually purchased the bigger van (still under 16') it had electric brakes but the synchroniser brake controllers were still all the rage.

As far as your description of the effectiveness of mechanical brakes go, I have not found them that poor. The first van I towed was a Franklin Hunter with hydraulic brakes. The difference in braking between having the reverse lock on and off was similar to the electric brakes with the trailer plug in and the trailer plug forgotten to be inserted. Or to put it in simple terms, the feeling when braking in the two vans with and without brakes was similar.

During the time I had my Nipper I was living in the ACT. We had annual vehicle inspections there and the brakes were thoroughly tested. The first generation tester had 4 individual wheel areas that were topped with expanded steel on the top. When you drove over them you were given the signal to brake hard. The forward movement of the pads pumped up individual columns of coloured liquid. That showed how effective your brakes were. I was surprised how this test demonstrated the effectiveness of the override brakes. I thought the van would have been so light that its tyres would not have gripped the pads very well. The height of the column was much higher than my Morris 850 produced. The second generation tester employed a pair of driven rollers that each wheel sat between. With that test they asked you to reverse the van up against the rear roller and the result was displayed in 7 segment display tubes. Again the brakes performed well, both in the override mode and applying the handbrake tests.

I therefore have to disagree with you on the effectiveness of override brakes. We have progressed to electric brakes not because the override brakes were so poor, but because the electric brakes are better. You were sounding like the brakes of the day were poor, but they of the standard of the day, and the manufacturers should have been using the brakes we now have available.

On the subject of mechanical brakes, here is something for you to mull over - Mechanical vs. Electric Brakes. Mechanical brakes have also improved since those days, not just electric ones.

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Reply By: Gbc.. - Monday, Oct 30, 2023 at 08:53

Monday, Oct 30, 2023 at 08:53
Yes, our TrakShak came with an overrider drum brake setup on the handbrake and also normal electric brakes. I retro fitted a pot controller into the trailer so my sister could have decent brakes when she borrowed it and didn't have a car mounted controller.
As said, just flip the reverser lock on and the elecs work as normal. The override drums as you'd imagine were never awesome and constantly needing adjusting - leaf springs travel in an elipse as they load up so if you loaded heavy or hit big bumps the brakes could engage if not adjusted well enough....
I believe it was on this forum about 15 years ago that I was 'informed' that i didn't have that setup and that it was impossible - haha
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Follow Up By: Nomadic Navara - Monday, Oct 30, 2023 at 11:12

Monday, Oct 30, 2023 at 11:12
"I believe it was on this forum about 15 years ago that I was 'informed' that i didn't have that setup and that it was impossible - haha"

So much for the armchair experts on these forums.
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Follow Up By: RMD - Monday, Oct 30, 2023 at 11:25

Monday, Oct 30, 2023 at 11:25
I think GBC has nailed it by saying, he did work so his sister could have decent brakes. Yes, you can make a thing pull a cable, but in anyone's language it isn't really a brake system anyone would want to have apart from none at all.
The ones who tried it didn't really understand how Servo brakes operate, ie, leading/trailing shoe, as most are.
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Follow Up By: Gbc.. - Monday, Oct 30, 2023 at 11:50

Monday, Oct 30, 2023 at 11:50
Yes, I've had cable override disks and hydraulic override disks on boats that got the job done no worries - again assuming the load state and spring shape stayed fairly constant - we have a 1.4t work trailer with cable override disks that do nothing when the trailer is empty but the cable takes up as the trailer gets loaded with whatever. One of our tradies thought he'd 'fix' it by tightening the cable when the trailer was empty and next time someone went and got a load of dirt the brakes locked up solid....
Override drums on the handbrake lever weren't an awesome 'invention' at all IMHO -because they only activate the trailing shoe.
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Reply By: tonysmc - Monday, Oct 30, 2023 at 13:29

Monday, Oct 30, 2023 at 13:29
Thank you to everyone that replied.
I’ve always had a curiosity of how things work and when I heard people claiming they had combination of electric and override brakes it sparked my interest as I thought it didn’t sound correct.
A couple of you confirmed you had heard of it, with one even had that set up.
As I said I would, I dropped into the trailer business and they also confirmed that they have seen it many times.
So, I have learnt something new that I will probably never use in life. Maybe if I see an override coupling, I won’t assume it doesn’t have electric brakes. I’m not advocating it’s a good system, but I suppose if someone was to upgrade to electric brakes it may make sense to keep the override system as well.

Cheers
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Follow Up By: RMD - Monday, Oct 30, 2023 at 14:15

Monday, Oct 30, 2023 at 14:15
Tony
The internals of the modern electric brakes are cable operated for handbrake reasons and designed that way. The concept being discussed is only some sort of action which tugs the cables when trailer overrides the vehicle as it brakes. Since the whole idea relies on a leverage system on a short stroke slide it is dubious how it can be effective unless purposely tuned to actually do something and tested too before it was used.
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Reply By: noggins - Saturday, Nov 04, 2023 at 19:05

Saturday, Nov 04, 2023 at 19:05
I had a small 14' Viscount many years ago that had over-ride brakes fitted from new.
Being cable-operated the ride height of the springs either with the van loaded or unloaded did affect the stopping,( I suppose you could call it) "Rate"
I ended up using brake cables slightly modified from a Holden that had the cable to the drum run through in a heavy outer flexible braided sheath
It took about 1 hour to modify the cable mounts onto the chassis and as the supporting clips were already on the brake backing plate that end was really easy
Then a simple single adjustment of the cable was all that was ever needed until I later retrofitted electric brakes when I had to replace the brake shoes due to being worn out.
I simply flipped the reversing lockout when parking, and just once, I didn't have the electrics adjusted hard enough and the over-ride brake came on in a HARD Braking emergency.
It is possible to have both working for sure, but you do have to remember to flip the lock when reversing into a site.

Note :- It's a pity some of the Ex Sperts here do not read and duplicate the posts
It would have saved Peter a heck of a lot of correspondance
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