Trailer parking HYDRAULIC brake.

[Reg]

How I got to here and why.... lets skip that for now.

What I have is a trailer with hydraulic brakes on it.
What I want/need is a parking brake.

Ok, I know about wheel chocks, but those don't qualify as a "Parking Brake".

So, given that I don't have drums with backing plates that have the lever to a cable - and I don't want to fit them.

Is there a neat and reasonably simple way to add a secondary "device" to apply hydraulic pressure ?
I have looked at hydraulic hand brakes used in drift cars for skidding the back end out (Rally trick) and that seems
reasonable as the actuating mechanism, it already has a locking button.

Where I'm having trouble is figuring how to splice into the hydraulic braking system;
1) If I just Tee in the pressure of the handbrake would just go back to the regular master cylinder.
2) If I Tee in and add some sort of a reverse flow blocking valve in the master cylinder's line I need a way
to unblock that or it would block normal release of the brakes.
3) This may be too fancy, but it would SEEM that a solenoid operated block/shut-off in the line from
the master cylinder would do it and the way to wire that would be from the trailer plug AUX line,
I would need an "energize to open" type of valve.
This would automatically shut when the trailer is disconnected from the truck, but wouldn't interfere
with the breakaway system.

I acknowledge that hydraulic leak down happens, this would NOT be a substitute for wheel chocks.

Is there a simple known solution to this ?
Just ~$100 or so in parts ? (-:

Ideas are welcome - other than attempts to talk me out of this or question the want/need (-:

 

[bcp]

You might be able to use steering brakes:

Pacific Customs: Steering Brakes and Dune Buggy Parts, Sandrail Parts, VW Parts

Bruce

 

[Reg]

Thanks, but I think the hydraulic parking brakes that I already mentioned may be a better choice
because they have the lock button already in the handle.
This is for the thumb when in normal driving position, but if I mount it where I want to on the trailer
I may have to pull with one hand and press the button in with the other.

I only need ONE, so a paired set is redundant.

 

[bamboozled]

I guess I don't see the point of why you are trying to do this.

Are you wanting to use it while connected to the tow vehicle or disconnected?

Assuming you have surge brakes with drums and want to do this with the trailer disconnected, only way I can see this working is if you use a line lock after the master cylinder, before the brakes. You would have to manually activate the brakes, then set the line lock, and that might work. But its only going to keep the trailer from rolling forward, not backward. I suppose the cutting brakes would work, but a line lock would be simpler.

Trailer brakes are usually finicky enough as it is, I don't think I would want to have them actuated and sitting, seems like it would lead to them sticking to the drums.

 

[94BULLITT]

Would a line lock work?
http://www.summitracing.com/search/part-type/line-locks/section/line-locks

I would not want them sitting around for a long period of time locked.

 

[Reg]

Line locks would be what I want, except for the fact that they only lock when there is power to the solenoid.
I think a solenoid operated changeover valve would work; plumbed so that when energized it connects the
master cylinder to the brakes for normal towing, when relaxed (no power to trailer) it connects the parking
brake to the wheel brakes and BLOCKS pressure back to the master cylinder.
About 1/2 of what people are using for their grapples, switching from bucket dump/roll to grapple open/close.
Yeah, I think them's the parts fer this projekt.
Surplus Center here I come - AGAIN !

Not to worry about drums being left on for extended periods, I just converted FROM drums TO discs.
12 1/4 by 3 3/8 drums WERE on it, pleased to be rid of 'em (-:

 

[DT86]

What about this. Brake Lock

 

[Boostinjdm]

I'm not sure I would trust a hydraulic set up for any length of time. You may come back a couple days later and find your trailer at the bottom of the hill. What's wrong with wheel chocks?

 

[kennyd]

We used to use Mico or Micro-Lock systems on our bucket trucks years ago. The line locks are available Ina non-electric option as well.

 

[CDN Farm Boy]

I'm not sure I would trust a hydraulic set up for any length of time. You may come back a couple days later and find your trailer at the bottom of the hill. What's wrong with wheel chocks?

My thoughts exactly. I fail to see the point of it.

Can someone identify any vehicle that uses hydraulic parking brakes rather than mechanical?

There are full mechanical line-locks available that you'd have to activate at the tongue.