"That is not a very safe thing to do: reason being the truck's brake system has just enough capacity to actuate the 2 cylinders and 2 calipers on the truck. You would be having to activate 6 cylinders and 2 calipers on a system that was designed for half of that load."

The hydroboost systems have enough oil capacity to operate the brakes and the steering. Brakes take a relatively small amount of oil compared to the steering. It would depend on how you did it.

"Second, if you were to have a hose failure between the truck and trailer (not as uncommon as you might think) you would lose all brake capabilities on the truck and trailer."

Depends how you did it. The truck has 2 brake circuits. The hydroboost pump supplies the master cylinder and that is all. If a brake line failed, the master cylinder would lose pressure in one circuit and that is all. The pump doesn't actually power the brakes, only the master cylinder.

Ideally one would have a 2nd master cylinder for the trailer operating in the same fashion.

"Getting a pressure signal from the master cylinder like the vac or air systems, and the Brakesmart electric controller do will not cause any increased load on the system. That is because those are just pressure sensors, not an actual set of wheel cylinders that has to be activated."

I understand that part.


"One other thing about connecting the trailer directly to the truck hydraulic system is that you have to use some kind couplings or the trailer would have to be connected all the time."

1/4" quick couplers, like what are used on tractors.

 

check ouy my pics. I have vacuum over hydrolic on my truck and trailer. I thought all our trucks had a vacuum pump on them? how else does the heating duct work work if there is no vacuum? the ford and chevy's pumps are not big enough, and they need an another pump but my dodge will peg my guage and never run out of vacuum. no matter how much you pump the brakes. I bought my unit on ebay for $200 and my dad got his for $35 . setting up the trailer, that might be pricey, but to hook up the truck is a 1 hour job

 

Superduty, it's much more complicated than that. If you want an in-depth description and response to it, feel free to give me a call tomorrow evening when I have some time and I will try to explain the entire brake system and how it is not capable of the extra capacity and how the hydroboost system works.

-Trey

 

When I used to hot shot I got tired of the electric brakes too. The electric brakes will work if you don't roast them on the down grades. The jake on the truck is the way to go.
I was hauling loads of hay on the side scaleing up to 26k and needed to move more at a time to be profitable. So I got a 30ft. tandom with 12k vac/hydrolic disk brakes, and hauled as heavy as 42k once, averaged 35k. You could stop fast with any load, but empty you smoked the tires if you didn't soft pedal it. I lit the tires up a few times empty.
I transfered my system two times and it didn't take long once you knew what to do to set up the next truck. Infact I still have the truck part laying out in the garage. Vacume presure gage and all.
In MHO I would stay with your electric brakes and get the jake. My uncle did that with his Dodge and loves it. He doesn't have the ride the brakes very much if you slow down at the top and don't try going down at the speed limit. His truck is an automatic.

 

I hated the brakes on my 5th wheel, too, until I got a Brakesmart- Didn't know electric drums were capable of the kind of smooth stopping power I have now. The Jake is awsome for holding the speed steady on long decents, and the combination has me pretty happy.

How heavy is your trailer, and what controller are you using?

IF the trailer is under about 15k I guess I would suggest installing the Jacob brake, and getting a Jordan Ultima or Brakesmart (if you don't already have one) see how you like it before spending major cash converting the trailer...

Just my non-expert $.02...

 

"I thought all our trucks had a vac pump on them? how else does the heat duck work work if no vac. the ford and chevy's pumps are not big enough, and they need an ele. pump but the dodge will peg my gauge and never run out of vac."

No, not all trucks have vacuum anymore. The HVAC stuff on the Fords is run by a small vacuum pump, and I mean small. On the newer Dodges, the HVAC stuff is run with motors. I don't think the new Dodges have any vacuum on them anymore.

"Superduty, it's much more complicated than that. If you want an in-depth description and response to it, feel free to give me a call tomorrow evening when I have some time and I will try to explain the entire brake system and how it is not capable of the extra capacity and how the hydroboost system works."

Depending how it is done... I know how the hydroboost system works. Just like the vacuum system except for on the other side of the master cylinder the piston is smaller and it is run by power steering fluid, not vacuum.

Thanks for the offer to discuss it though. I'll do some digging first.

I know what you mean about the pedal going soft if 4 more trailer cylinders were tied into the brake circuit itself.

What I am thinking is this:

a) two trailer axles with hydraulic brakes.
b) a hydraulic line run to the back of the truck with a quick connect. Like a tractor, but use 1/4" instead.
c) a hydraulic accumulator so that there is hydraulic pressure to apply the brakes in the case of a run away.
d) some sort of modulator that controls the pressure to the brakes themselves. The modulator would connect to the brake controller.

The thing about this system is that a guy wouldn't have to buy a $500 pump and the brake response would be instantaneous because the pump is always running.

"When I used to hot shot I got tired of the electric brakes too. The electric brakes will work if you don't roast them on the down grades. The jake on the truck is the way to go."

I've got one ready to install. I'm not pulling again until summer, so I'll put it on in the spring.

"I was hauling loads of hay on the side scaleing up to 26k and needed to move more at a time to be profitable. So I got a 30ft. tandom with 12k vac/hydrolic disk brakes, and hauled as heavy as 42k once, averaged 35k. You could stop fast with any load, but empty you smoked the tires if you didn't soft pedal it. I lit the tires up a few times empty."

The trailer has to adjust separate from the truck.

"I hated the brakes on my 5th wheel, too, until I got a Brakesmart- Didn't know electric drums were capable of the kind of smooth stopping power I have now. The Jake is awsome for holding the speed steady on long decents, and the combination has me pretty happy."

I can hold the trailer on long descents. What I am worried about is a panic stop. Even with 12A going to the trailer brakes, I can't lock the trailer wheels.

"How heavy is your trailer, and what controller are you using?"

10K+ I've got a Jordon Ultima. It works very well. I just want more braking power in emergencies.

 

You don't want the trailer brakes to lock up ever, at least not on pavement. When my trailer was loaded I couldn't lock up my disk brakes either. If you are looking for that kind of stopping power your going to have to have a seperate system that only read how much your pushing on your brakes. Disk brakes not drums they fade fast with that much pressure. Its been 8yrs since I was around that stuff. The electric over hydrolic sounds great for you but when I was around it the electric pumps were not up to the job. They were always going out. .02

 

Superduty,
A lot of people have posted some good information on this subject and yet you are still entertaining the idea of tapping directly into the hydraulic brake system of your truck. Forget about the hydroboost system because it is only an assist system so you don't have to press on the brake pedal so hard.

The fact is that it's not a good idea and will give you nothing but trouble everytime you try to use it. If you think that $500 is a bit much for a tried and proven braking system, wait till you try to design your own system. After you've spent a bundle of money and still don't have a reliable system $500 would have been a bargin.

The fact is that when the engineering is applied to this idea it just doesn't fly.
The master cylinder is sized for the fluid displacement of the brakes on the truck and there isn't much left over for additional wheel cylinders. The only way to add more cylinders is to increase the master cylinder displacement. That would mean a bigger master cylinder and that's possible but then we have to think about the connection between the truck and trailer. There isn't an easy or safe answer to this problem. Most likely you will end up bleeding the brakes on your truck and trailer every time you hook or unhook the trailer.
Not my idea of a good time.

The idea of using an additional master cylinder is a good one but only if that cylinder was permanently mounted on the trailer. That's where we get into the electric, vacuum, or air system to active it. A leakage of any of the three would not compromise the tow vehicle brakes because the brakes on the tow vehicle and the trailer are isolated from each other. On the other hand a hydraulic leak is not acceptable at all.

Keep the electric or spend the money for something better, there's just no safe way around it.

Hyspeed

 

I wish you all would use some other term then "Jake " as there is no such deal in the little cummins world.....just a exhaust plug

 

Well, it is an exhaust brake instead of an engine brake, but it is Jacob brand...

 

I don't even consider electric brakes to be brakes at all.

Exactly what durasmack said, if you want real brakes, get vacuum-over-hydraulic.

If you had sense enough to get that Cummins screwed into your Ford, then mounting a little-bitty belt-driven vacuum pump shouldn't be no hill for you to climb.

My truck/trailer/big load of horses will stop quicker with vacuum-over-hydraulics than the naked truck by itself.

They are worth every cent they cost.