Thread: trailer breaks/kits

looking at building a 3x2m flat deck trailer and wondering if anyone had any experience of mechanical vs hydraulic breaks (trailer wont get regular use just on occasion).
currently planning on rated to 2.5T or potentially non braked to 2T. also does anyone have any recommendations kits to use (hubs, springs, lights, etc)?

That is one set of kit that isn't getting any cheaper... I'd caution on the 2t unbraked as you are exceeding the regulated unbraked tow rating of the vehicle towing the light trailer (regulated max unbraked is 750Kg). I've heard of some people who have run into insurance issues with accidents while towing.

I've got an unbraked tandem contractor trailer here that we were looking at getting converted to one braked axle - used to be a pretty cheap and simple conversion with a caliper bracket to fit standard RHS axles and you could pick up a kit for around $600 to do it. Best I could do buying all new was $1200 for a basic kit - bloody near fell over! Also WoF are getting a bit twitchy about trailers that are obviously able to be loaded past 750Kg - this is the issue we had with the tandem unbraked as it's 550Kg empty (solid little hua) and they are looking sideways at us just loading 200Kg. Yeah yeah it's used for plastic pipe nudge nudge wink wink.

Mechanical brakes are pretty much reserved purely for the parking brake for electric over hydraulic TB-class (3500Kg) trailers now, not worth investigating as a standalone. I would park electric drums in the same category - they work well but have issues like the requirement for an in-cab controller to get the best performance out of them.

Best, easiest, simplist and most reliable trailer brake setup is hydraulic with the override type coupling (coupling slides back pushing the lever onto the trailer master cylinder which applies the brakes to the level that the trailer is pushing the tow vehicle for in-built proportioning). What I've just found is a Trademe seller getting rid of 6 sets of calipers needing rebuild (I've got a few caliper spares here already), a pair of stub axles and a duo-fit override coupling (all up under $130). An installation kit and a master cylinder with lever and a few misc fasteners and good to go... The only other bit I'll need to fab up is a set of caliper brackets to fit the 50mm RHS axle tubes - you used to be able to buy them off the shelf but not any more. Cheapest I can do it for to be realistic and not shortcutting on any of the equipment (rebuilt calipers and couplings are fine, I use brand new brake cylinders fittings and pipework). To buy a complete kit off Trailparts or CM was prohibitively expensive for what we were looking at, as with labour and install it became cheaper to buy a new trailer!

Lights are a bit of a suck it and see - Hella and Narva make good LED's (not worth fitting incandescent bulbs now) but they are not cheap. You need to be a little careful with the cheaper options as well as often times they are orphans and you cannot replace like for like. If you can stretch to the top name gear for a new build you'll buy once but cry once. I've used several cheaper options in the past that were rated IP67 or better but flooded quickly and failed not long after. As far as fitting I would connect and terminate using either solder and two layers of glue lined heat shrink or use duraseal crimps and also find a way to run the cable with a reserve or excess amount tucked away to allow replacement and servicing of the lights. Also marine grade tinned cable - it's not uncommon to see trailers that have never been swimming turn up with buggered cheap cable that has fizzed down it's length and needing replacement. Usually it's the negative/earth cable (if you use the full 7-core cable you can get away with using one of the accessory cores to replace the earth, but most often they have fitted cheap crap 5-core so you're buggered and need to replace the lot).

Cheers for that. Seems I over looked the vehicle ratings and only looked at the trailer regulations. Hydraulic brakes it is. So buying individual components might be the way to go to ensure high quality parts.

Mechanical brakes hands down best. European system with mechanical rods, cant leak, cant fail cant get out of balance between sides. I have a trailer sitting here that was made in europe ( not mine) and the build is way better than local gear. Clean, simple, sensible

Originally Posted by No.3

That is one set of kit that isn't getting any cheaper... I'd caution on the 2t unbraked as you are exceeding the regulated unbraked tow rating of the vehicle towing the light trailer (regulated max unbraked is 750Kg). I've heard of some people who have run into insurance issues with accidents while towing.

Good words here, but not entirely legislate yet. We have a grey area in our towing laws whereby the NZ trailer tow ratings do not line up with the vehicle manufacturers rating. In Aussie they do under ADR63 regs and currently NZTA is planning on a major review on this subject, as I have sat in on a meeting in Wellington relating to it.
I would suggest you go down the hydraulic disc brake on one axle of the tandem trailer rated at up to 2500kg. Make sure your tow ball is rated high enough as well, would suggest a 1" shank ball is used as well to obtain the correct rating.

https://www.facebook.com/pg/TinyHous...=page_internal

The photos are from trailers for sale at Kaiapoi. Can get some idea of the mechanical brake actuator from the photos.

Originally Posted by Moa Hunter

Mechanical brakes hands down best. European system with mechanical rods, cant leak, cant fail cant get out of balance between sides. I have a trailer sitting here that was made in europe ( not mine) and the build is way better than local gear. Clean, simple, sensible

While @Moa Hunter is correct in what he says with mechanical rods, against that no one in NZ is manufacturing them to my knowledge and supply lines if (or to be fair, when) you damage something could be problematic. My own experience of mechanical brakes is they do get out of balance and they are also a lot more expensive, bulky, more prone to damage and also heavier than the equivalent hydraulic. Apart from some sort of specialist reason that I can't currently think up hydraulic override is the most simple to configure and also easiest to source parts for in NZ.

I've converted two electric drum brake setups and one mechanical to the hydraulic override for that reason (the electric drums while effective need to be used otherwise they seize up quickly) and the mechanical setup was good but we couldn't get parts locally (all indent from Aussie as the nearest agent).

I've converted one hydraulic override to electric over hydraulic (TB-class 3500Kg) as that was set up with one 3/4 master cylinder driving two axle sets of calipers and one 3/4" master cylinder doesn't produce enough oil volume to drive two sets of calipers. Thats why a 2500Kg trailer will only have one axle braked - the brake master cylinder can't drive any more. Interestingly enough, the Trojan style calipers are rated to a max of 2000Kg per axle (on 275mm discs - the usual size you encounter is 225mm@1400Kg) so theoretically aren't rated to stop a 2500Kg trailer. I don't have the Al-Ko or Trigg specs off the top of my head, but they probably aren't rated much more.

The hydraulic systems are the least prone to damage as the bundy tube and hoses do not project out from the chassis of the trailer, and apart from a mechanical kink in bundy tubing the worst you can expect is overheating through operator error or some sort of foreign crud jamming the works up (sticks and stones haha are bad for that if you go off road a lot). The benefit of the override hydraulic systems which to my experience no other system has is that on a downhill the trailer will lightly apply the brakes on itself independant of the towing vehicle as the trailer weight tries to override (or overrun which is the other name for the system) the towing vehicle. This helps keep everything in a straight line and also minimises wear and tear on the towing vehicle.

The legal requirement is be able to stop with 7m from 30kmh, if cantcdo that with anticipated load add brakes (consider wet roads etc) I contacted my insurance, asked people in industry etc when had my boat, there was a bit of back and forward and difference of opinion but that is where it landed. I'm looking at a new trailer (will likely end up building) and will be looking for braked options to keep things simple

Yes that's correct, 7m/30Km/H flat standard-friction ground.

Legal requirement is one thing, the one that tends to create the most issues at the moment is insurance compliance and getting them to pay out if you have a whoops. Insurance companies damn well know that there are issues with the regulations and make a point of hunting them to look for the easy out. The towbar regulations for towing vehicles are the main out for them, if you go over 750Kg unbraked most likely congrats here's your refusal for claim #xxxxxxxxx (and thanks for your continued business) - especially if you slide into someone else's rear bumper. The issue we had was just that - it doesn't actually matter what the trailer regs say in terms of insurance as most people don't actually separately insure their trailers (with the exception of boats or machinery) but include them under the towing vehicle policy. That's where the insurance companies have you by the balls.

Easy way to make it difficult for the insurance company that holds the policy on your vehicle is not going over 750Kg unbraked, keeping to the loading recommendations for towball downforce (10% to a max 350Kg), max towed mass staying within the GCM limits (which means in a lot of cases you can't load the tow vehicle up and drag a large loaded trailer), and staying within the coupling and equipment ratings. Also as someone mentioned up above towball max load (some vehicles with max 1600Kg towed weight limit are fitted for 3/4" shank towballs which can be limited to 2000Kg, 1" shanks are often 3500Kg rated although this varies), and the other is correct rated safety chain(s) with rated shackles and not hardware chain and shackles from the local dairy...

Another good one is interchangeable towball setups where the wrong ball is used, or duofit (1-7/8 or 50mm) couplings with the 50mm setting used on a 1-7/8 ball... I see this so often it isn't funny!

And a last mousetrap - especially 3500Kg trailers is cracking 6000Kg on a Class 1 car licence. Easy to do, and good for a walk home too.

Shame that class 1 6000kg rule isnt better policed. I get really frustrated with the dangerous poorly / overloaded trailers and horse floats getting around on a car licence and a light truck as a single vehicle with really good big brakes must run on an HT.

Originally Posted by No.3

While @Moa Hunter is correct in what he says with mechanical rods, against that no one in NZ is manufacturing them to my knowledge and supply lines if (or to be fair, when) you damage something could be problematic. My own experience of mechanical brakes is they do get out of balance and they are also a lot more expensive, bulky, more prone to damage and also heavier than the equivalent hydraulic. Apart from some sort of specialist reason that I can't currently think up hydraulic override is the most simple to configure and also easiest to source parts for in NZ.

I've converted two electric drum brake setups and one mechanical to the hydraulic override for that reason (the electric drums while effective need to be used otherwise they seize up quickly) and the mechanical setup was good but we couldn't get parts locally (all indent from Aussie as the nearest agent).

I've converted one hydraulic override to electric over hydraulic (TB-class 3500Kg) as that was set up with one 3/4 master cylinder driving two axle sets of calipers and one 3/4" master cylinder doesn't produce enough oil volume to drive two sets of calipers. Thats why a 2500Kg trailer will only have one axle braked - the brake master cylinder can't drive any more. Interestingly enough, the Trojan style calipers are rated to a max of 2000Kg per axle (on 275mm discs - the usual size you encounter is 225mm@1400Kg) so theoretically aren't rated to stop a 2500Kg trailer. I don't have the Al-Ko or Trigg specs off the top of my head, but they probably aren't rated much more.

The hydraulic systems are the least prone to damage as the bundy tube and hoses do not project out from the chassis of the trailer, and apart from a mechanical kink in bundy tubing the worst you can expect is overheating through operator error or some sort of foreign crud jamming the works up (sticks and stones haha are bad for that if you go off road a lot). The benefit of the override hydraulic systems which to my experience no other system has is that on a downhill the trailer will lightly apply the brakes on itself independant of the towing vehicle as the trailer weight tries to override (or overrun which is the other name for the system) the towing vehicle. This helps keep everything in a straight line and also minimises wear and tear on the towing vehicle.

Looking at the drums on the mechanical brakes they look for all the world like the rear drums on a VX Cruiser with the cable handbrake actuator that works over the hydraulic drums - the drums have have hydraulic and mech actuators on the one set of brake shoes.

Ahh that's more like the the TB-Class (3500Kg) trailers with the electric or electric over hydraulic actuators, must have a means of holding the trailer on a defined slope with no power to the electric brake system. That means a cable parking brake setup on a separate calipers for disc brakes or the dual actuated shoes on drum brakes. Drums are actually the better system in outright performance, but with the issue of corrosion, water ingress and fade. Plus drums can be a pain to set up, calipers are easier to swap pads out bleed and do all the other maintenance tasks.

The other interesting thing with TB-Class trailers is the breakaway rule, requiring a breakaway switch and a battery setup that operates the brake system long enough to stop the trailer. Now that's great in theory, but the rules are a bit ambiguous on the use of safety chains with a 2501-3500Kg trailer meaning that some inspectors are requiring crossed safety chains (which should be for the 2001-2500Kg weight class) which effectively makes the breakaway system useless and leaves potentially 3500Kg's flopping around on the back of the (usually lighter) tow vehicle. I'm not sure why they are doing this, as the rules are meant to be interpreted in the safest manner and for me the breakaway system is much better than the crossed chains in that weight class.

I had a fairly robust discussion with the local VTNZ outfit with that trailer I had to convert - now this was for a trailerable barge and the rig had a road weight of 3485Kg (fairly well worked out haha). They went into the computer on one WOF check and it was registered as a TA-Class single axle general purpose trailer. Oops. So the point of correcting the rego details opened a few worm cans, one of which was the override coupling rated at 2500Kg failed the new WOF check, only one safety chain, one master cylinder so brake performance was below spec for two braked axles and it went on from there including the fact that the parking brake wasn't up to spec for the weight as the master cylinder went straight to the floor. About $3500 later in hydraulic actuator and the TB-Class kit to convert the thing to the 'right' spec and I went back in - only to get failed on no safety chains which was a requirement of the trailer inspection form at the time. Hmmm - as I said not required due to the breakaway switch and demonstrated it in use. Scratch head, followed by the other two inspectors summoned, heads together for the obligatory pow-wow, heads up for a meercat looking at the trailer, heads back down, hmmm again. Inspector says wait one, steps into the office and a call to somewhere and 5 mins later walks out and everything was right in the world. Well I got the sticker haha.

Our first thought with this issue of the insufficient braking performance was to fab up a dual-master-cylinder adapter to fit two master cylinders to the override coupling, But it wouldn't meet the specs for the weight class so no point... Would be good for a 2500Kg trailer that you want to have good stopping power though and it woud give good redundancy to have two separate hydraulic systems on the one trailer.

Originally Posted by No.3

The other interesting thing with TB-Class trailers is the breakaway rule, requiring a breakaway switch and a battery setup that operates the brake system long enough to stop the trailer. Now that's great in theory, but the rules are a bit ambiguous on the use of safety chains with a 2501-3500Kg trailer meaning that some inspectors are requiring crossed safety chains (which should be for the 2001-2500Kg weight class) which effectively makes the breakaway system useless and leaves potentially 3500Kg's flopping around on the back of the (usually lighter) tow vehicle. I'm not sure why they are doing this, as the rules are meant to be interpreted in the safest manner and for me the breakaway system is much better than the crossed chains in that weight class.

The reason for this is, recommending safety chains being used in conjunction with breakaway (NZTA Verm in 2021) was to add safety to oncoming traffic if the trailer was to disengage with the tow vehicle and cross into the path of another vehicle. Electric drum brakes are prone to imbalance and with breakaway activated can veer off the path of travel, if indeed the breakaway works at all.

Originally Posted by Mathias

The reason for this is, recommending safety chains being used in conjunction with breakaway (NZTA Verm in 2021) was to add safety to oncoming traffic if the trailer was to disengage with the tow vehicle and cross into the path of another vehicle. Electric drum brakes are prone to imbalance and with breakaway activated can veer off the path of travel, if indeed the breakaway works at all.

So what's the point of a breakaway system if you tie the trailer to the towing vehicle which means the breakaway can't (or more than likely won't due to the relative length of the breakaway cable vs the safety chains) activate?

Also, what usually happens if the tow hitch disconnects from the towball is that the trailer heads off the camber to the left dragging the tow vehicle's arse left and punching the front across the centerline. Bloody counterproductive is what that is, safest option is a) build the roads properly with correct cambering, and b) have the greatest mass vehicle separate from the tow vehicle and apply it's brakes as it heads off to the left following the (correctly road engineered) camber.

Not getting at you personally @Mathias, but the brains trust in Wellington needs to sort this sh1te out and decide which way they are going with these things because the status quo is just confusing and way behind best practice overseas. The fact we can't run air/over systems like other jurisdictions is a complete joke.

Originally Posted by No.3

So what's the point of a breakaway system if you tie the trailer to the towing vehicle which means the breakaway can't (or more than likely won't due to the relative length of the breakaway cable vs the safety chains) activate?

Also, what usually happens if the tow hitch disconnects from the towball is that the trailer heads off the camber to the left dragging the tow vehicle's arse left and punching the front across the centerline. Bloody counterproductive is what that is, safest option is a) build the roads properly with correct cambering, and b) have the greatest mass vehicle separate from the tow vehicle and apply it's brakes as it heads off to the left following the (correctly road engineered) camber.

Not getting at you personally @Mathias, but the brains trust in Wellington needs to sort this sh1te out and decide which way they are going with these things because the status quo is just confusing and way behind best practice overseas. The fact we can't run air/over systems like other jurisdictions is a complete joke.

Very true, NZTA have left it way too long to address the ruling and now it'll be a huge expense to the tax payer to put it in a more workable format. There is talk & plans of alignment with NZ 5467:1993 Code of Practice for Light Trailers but this has to be brought into the current century to be effective for a start, which they (NZTA) have acknowledged.
To scare the folks out there more, there's currently no legal standard required to build a tow bar suitable for under 3501kg for a vehicle with a WoF.

Anyway, you & I aren't going to fix it on the forum. As suggested, the OP would be wise to have at least one axle braked, preferably hydraulic override disc of good quality manufacture, proper safety chains & suitable tow bar etc.