Thinking about converting surge brakes to electric - Tri-Axle Trailer

[tpenfield]

My 2021 trailer came with surge brakes on all 6 wheels. Even so, stopping is a weak-point as it puts too much forward pressure on the truck. I'm assuming that with electric/hydraulic brakes the trailer will tend to stop more on its own.

I am thinking about a conversion to electric (what I understand to be called "electric over hydraulic"). The truck came with the "trailer brake controller", so I believe most of the work will be replacing the surge coupler with the electric actuator and various wiring.

Any experts in the group that can walk me through this a little bit? TIA

 

[Scott Danforth]

the electric over hydraulic replaces the surge actuator with a hydraulic pump and valve assembly. really straight forward.

however if your current setup is pushing forward on the truck, something is not working right.

 

[04fxdwgi25]

I did the conversion to EoH this past spring on my tandem axle trailer w/ disc brakes. Possibly the best conversion I ever made on a trailer, aside from discs. Trailer will actually slow the truck down if the gain is turned up a tad. Didn't replace the surge coupler, just modified it.

And no surge coupler clunk..... Big bonus.

All I had to do was add and wire the EoH unit to the blue brake, red trailer power and white ground wires, remove the MC and shocks from the coupler and move the hydraulic line to the EOH unit. Then need to lock the surge coupler from moving by drilling it and adding another 3/4" surge coupler pin to prevent the movement (Could have welded to lock, or added a 3/4" grade 8 bolt instead of the pin. but this was easier and cheaper). Then do a complete brake fluid flush with new brake fluid. EOH unit I used is a 1600 psi unit and plenty good for 3 axles of disc brakes.

https://www.etrailer.com/Brake-Actuator/Hydrastar/HS381-9067.html. Was on sale for $800 when I bought it.

 

[tpenfield]

. . . .
however if your current setup is pushing forward on the truck, something is not working right.

Yes, it might just be wet brakes or sticky calipers . . . I don't drive the rig often or far enough to really exercise the brakes. I took the trailer out on the road to test the brakes, as per my other trailer thread, and they are working . . . just not sure they are working well enough.

It seems as the weight of the towed load goes up, folks tend to favor electric brakes. My tandem trailer for my Formula 242 had surge brakes and they worked pretty well for that size of trailer/load.

Are you back from WI yet?

 

[Scott Danforth]

you may be running out of actuator volume with calipers on all 6 wheels.

got back late last night

 

[tpenfield]

you may be running out of actuator volume with calipers on all 6 wheels.

got back late last night

That is what I was thinking that the brakes are not fully engaging. If I were to go electric over Hydraulic, I'd want to make sure it had enough power/volume for 6 disc brakes.

 

[bruceb58]

I have put two EOH systems on two different trailers. Not hard to do. I suggest going with a conversion to all disc brakes while you are at it if you don't already have disc brakes.

What is your tow vehicle?

For my 2018 F150, I had to run a much larger gauge wire from the battery to the back of my truck and then to the trailer using Anderson connectors to allow the EOH pump to work properly.

I use the Dexter DX EOH unit on one trailer and the BrakeRite on the other. Both are tandems and both work well.

Most triple axle trailers I see these days for boats have EOH. Many triple axle 5th wheels are also EOH.

 

[tpenfield]

Thanks @bruceb58. I'll check out those EoH units.

The truck is an F-150 EcoBoost 4x4. The trailer has disc brakes on all 6 wheels.

 

[tpenfield]

@bruceb58 Another question . . . You mentioned needing a larger 12V feed wire on the F-150 (assuming to get enough power to the actuator). Would an on-trailer break-away battery supplement the power during breaking? or what that not enough? It looks like the Dexter 1600 psi actuator wants a 40 amp feed.

I assume the 1600 psi model is what I would want for the 6 wheels of disc brake.

 

[Scott Danforth]

Ted, you most likely will need to run 6 or 8 gauge back to pass 40 amps

 

[dingbat]

I assume the 1600 psi model is what I would want for the 6 wheels of disc brake.

Hydraulics is primarily a displacement game.

Pump capacity needs to be sized to demand. A #10,000 psi unit is useless of it can't supply the required displacement.

 

[JASinIL2006]

@bruceb58 Another question . . . You mentioned needing a larger 12V feed wire on the F-150 (assuming to get enough power to the actuator). Would an on-trailer break-away battery supplement the power during breaking? or what that not enough? It looks like the Dexter 1600 psi actuator wants a 40 amp feed.

I assume the 1600 psi model is what I would want for the 6 wheels of disc brake.

My breakaway battery only supplies power when the pin is pulled (i.e., when the trailer has broken loose from the truck). Otherwise, it does nothing but receive a charge when truck is running.

 

[bruceb58]

@bruceb58 Another question . . . You mentioned needing a larger 12V feed wire on the F-150 (assuming to get enough power to the actuator). Would an on-trailer break-away battery supplement the power during breaking? or what that not enough? It looks like the Dexter 1600 psi actuator wants a 40 amp feed.

I assume the 1600 psi model is what I would want for the 6 wheels of disc brake.

You could use a battery on the trailer if it was possible to charge the battery sufficiently through the 7 pin over time. In fact, on my travel trailer, I solely use the travel trailer batteries but I have 560AH of battery capacity so no need to worry about running down the battery. Personally, just run a 6 AWG wire from the battery, through a circuit breaker back to the rear of the truck. The Dexter pump unit I have has a timeout feature so there is no standby draw after around 30 minutes or so if the brake pedal isn't pressed.

You need a breakaway battery anyway so you will always have a battery on the trailer.

I 3d printed a mount for my SB50 Anderson connector at the back of the truck and have a mating connector on the trailer.

Out of curiosity, are you using a WDH? The F150 receiver hitch is rated for 500# dead weight. My tongue weight is 600#...I use a WDH.

 

[Lou C]

What is your hydraulic surge actuator rated at? Just curious….

 

[tpenfield]

What is your hydraulic surge actuator rated at? Just curious….

IDK . . . It is fairly massive. Might be the 12,500 lb. or 16,000 lb. capacity rating.

 

[tpenfield]

You could use a battery on the trailer if it was possible to charge the battery sufficiently through the 7 pin over time. In fact, on my travel trailer, I solely use the travel trailer batteries but I have 560AH of battery capacity so no need to worry about running down the battery. Personally, just run a 6 AWG wire from the battery, through a circuit breaker back to the rear of the truck. The Dexter pump unit I have has a timeout feature so there is no standby draw after around 30 minutes or so if the brake pedal isn't pressed.

You need a breakaway battery anyway so you will always have a battery on the trailer.

Out of curiosity, are you using a WDH? The F150 receiver hitch is rated for 500# dead weight. My tongue weight is 600#...I use a WDH.

I have the Class IV hitch (10,000 lbs / 1,000 lbs tongue wt), but need a WDH to get to 14,000 lbs.

Since braking is infrequent vs. driving, I figure the battery on the trailer will charge during non-braking and supply any additional current needed during braking. I think the Dexter Actuator wants a 40-amp supply.

 

[Lou C]

What I’m wondering is this….what’s the total load in terms of weight, my boat weighed quite a bit more than I was led to believe…not about 3,000 lbs more like 4,000. Tie down/Dexter make a 16,000 lb capacity actuator but Titan makes a 20,000 lb one. Perhaps upgrading the actuator to the highest weight rating you can get and making sure all air is bled out, might be a simpler solution. As an example my boat & trailer weighs in at 5050 lbs. The actuator is rated at 6,600 lbs & the surge brakes are rated at 7,000 lbs (12” drums). Even on the steepest hills we have here (north shore Long Island very hilly) it stops right now. So my thinking is your whole brake system might work better if it’s rated well over the weight of the towed load.
Have you bled the whole system? Might be worth trying that first. With 6 individual brakes there is definitely places for air to hide.

 

[tpenfield]

Since my truck has the brake controller, I'd rather go EoH than merely upgrade the surge coupler.

Ideally, I'd like the trailer to stop itself, not really relying on the force of the coupler pushing the vehicle. Surge brakes worked fine for my 24 footer & tandem trailer (6500 lb total load), but the CY338/tri-axle total load is 13,500-14,000 lbs. A different league. Often you find tri-axle trailers as having electric brakes rather than surge.

 

[Lou C]

Agreed that electric control should be better than the reflexive action of a surge system esp with that much weight is involved.

 

[bruceb58]

Since my truck has the brake controller, I'd rather go EoH than merely upgrade the surge coupler.

Ideally, I'd like the trailer to stop itself, not really relying on the force of the coupler pushing the vehicle. Surge brakes worked fine for my 24 footer & tandem trailer (6500 lb total load), but the CY338/tri-axle total load is 13,500-14,000 lbs. A different league. Often you find tri-axle trailers as having electric brakes rather than surge.

It's a no brainer for you to go EOH.