Poor Man's Electric Over Hydraulic

I was going to post this question latter but I ran across these threads.

The trailer that came with Absolutely has Hydraulic brakes. I was (am) having problems backing when it is level or up hill grade. I have wondered why there was not a switch or such to prevent the brakes from braking in this situation. I knew I was not the only one who backs up a boat trailer :o .

I have been using a block of wood to stop the compression of the trailer.

I too have a round 7 pin on my tow vehicle with a flat 5 way adapter to the trailer wires. So what I have read is that the adapter does not pass through the back up lights. The back up lights are what switches the solenoid to cut out the hydraulic brakes. HMM.

So do I need to wire a flat 5 way to my tow vehicle to make this work?

Thank you!!
 
The backup lights on the tow vehicle should go to that the fifth pin. That controls the lockout solenoid on the trailer allowing you to backup. You Should hear it click. They Do fail so you may need to replace the solenoid.
 
SPrice":2nvrpo37 said:
I was going to post this question latter but I ran across these threads.

The trailer that came with Absolutely has Hydraulic brakes. I was (am) having problems backing when it is level or up hill grade. I have wondered why there was not a switch or such to prevent the brakes from braking in this situation. I knew I was not the only one who backs up a boat trailer :o .

I have been using a block of wood to stop the compression of the trailer.

I too have a round 7 pin on my tow vehicle with a flat 5 way adapter to the trailer wires. So what I have read is that the adapter does not pass through the back up lights. The back up lights are what switches the solenoid to cut out the hydraulic brakes. HMM.

So do I need to wire a flat 5 way to my tow vehicle to make this work?

Thank you!!
Click to expand...

When you say hydraulic brakes so you mean:
a) Electric over hydraulic brakes (in which you have a brake controller installed in the tow vehicle and the brake system has an electrically controlled hydraulic pump) OR
b) Surge brakes (in which the hydraulic pump is a piston that is actuated by a the action of the hitch couple pressing against the hitch ball?

Assuming you have surge brakes (the most common thing), then you need to lock out the actuator for backing. Many trailers are setup to require one to manually move something to lock the actuator in place and to keep it from locking up the brakes when backing. The problem with this type of arrangement is that it's designed to unlock the actuator when you pull forward. Hence unless you can back up without forward and backward jockeying, the lock-out device doesn't stay locked in place unless you put something else in place to keep it from moving (some clamp a vice grip on for this).

The other alternative is to have a solenoid device that is wired through a 7-pin connector to the reverse lights on the tow vehicle. This (when working properly) will automatically lock out the actuator by applying power to a solenoid whenever the tow vehicle is in reverse. If you have such a lockout solenoid installed on your trailer's hitch coupler and you're still locking up the brakes in reverse, then either there's something wrong with the wiring (e.g. no power to the solenoid when in reverse) or the solenoid itself is no longer working.

If you're using the 7-pin to 5 pin adapter, it doesn't pass the reverse light through to the trailer. However, if the trailer is wired with a 5-pin straight connector, that would suggest that you don't have the hitch coupler with a solenoid lockout since it needs the 7-pin connector. If that's the case, you have a manual lockout and you'll need to engage it manually each time you back up. If so, I'd recommend you have the hitch coupler replaced (or do it yourself). It doesn't cost that much money to have a new coupler with electric lock out installed and it's a lot easier/better than the manual lockout system.
 
Thank you. I ment hydraulic surge breaks.

I will look to get a new coupler. Have any idea where best to get one?


Thank you so much.

Scott
 
SPrice":y1ditn9x said:
Thank you. I ment hydraulic surge breaks.

I will look to get a new coupler. Have any idea where best to get one?


Thank you so much.

Scott
Click to expand...

Scott,

Any good trailer place should be able to swap out the coupler. I've used Gary Estes Mobile Repairs, 280 NE Juniper St, Issaquah (206) 999-2320 at the recommendation of other brats for trailer work and have been happy with him. You can also find the parts online if you wish to do the work and feel comfortable bleeding your own brakes. To bleed the surge brakes you'll need a hitch ball on a lever arm so you can cycle the actuator on your own. For me, it's a lot easier to just pay someone to do the work.
 
SPrice":16aerb7w said:
Thank you.

Wouldn't it work just to rewire the trailer to a round 7 pin?

Scott
Click to expand...

If you have a solenoid lockout on your coupler yes. If you don't, then no. Maybe you should post a picture of the trailer coupler.
 
rogerbum":xcspy09u said:
If you're using the 7-pin to 5 pin adapter, it doesn't pass the reverse light through to the trailer.
Click to expand...

Could I make sure I'm understanding this correctly? What I'm reading here is that if I have a 7-way on the tow vehicle, and a 5-way-with-blue-wire on the trailer, I cannot effectively join these with a 7-way to 5-way adapter on the tow vehicle because that will not activate the blue wire on the trailer?

My trailer has (new) disc/surge brakes, and a new brake actuator which does have the 5th (blue) wire. It also has a manual brake-lockout pin, but I would like to take advantage of the "automatic" lockout provided by the blue wire.

Right now my tow vehicle has a 4-pin flat connector, so I'm going to be changing it. From what I have read, there may be a 7-way connector stuffed up behind the bumper somewhere, so I will be checking this. I was thinking that if this were the case, I could run with the 7-way on the tow vehicle, and get a 7-way to 5-way adapter to connect tow vehicle to trailer. Am I understanding correctly that this will not work?

A couple of reasons why I would go with 7-way connector on tow vehicle vs. 5-way flat (only if it would work of course):

a) I think the 7-way may already be there on the tow vehicle.
b) I might like the option of making a system to charge boat battery when underway trailering.
c) If I ever add electric-over-hydraulic brakes I'll need 7-way anyway.

Of course the main thing is to make the lockout work now, although if I cannot, at least the pin lockout can stay in for an extended period of backing and filling (as long as I remove it before getting out on the road so I still have brakes).

Thank-you,
Sunbeam :hot
 
That blue wire, or 5th wire on the 5-pin or 7-pin connector is the Backup Light wire. On my trailer, I used that wire to activate a "blocking" solenoid that I added in-line with my brake line feeding all 4 brakes, close to the trailer's master cylinder. You don't need a new master cylinder or coupler, just buy the solenoid from Tie-Down Engineering, about $55.

You will need to bleed the air out of the brake system. Not as easy as a car because you have to figure a way to slowly compress the coupler while another person opens/closes the bleed screws individually on each wheel -- starting with the wheel furthest from the coupler. I used my son and a crowbar against a 2x4 in a particular spot on my trailer!

I added a dash switch to provide the solenoid activation manually instead of through the backup lights. It worked fantastic on my recent trip down the Grapevine on I-5 going to the Delta Extravaganza. It also works perfectly backing up my driveway whereby I generally have to straighten out the wheels a bit before continuing into the parking space.

Why I needed the switch rather than just the backup light activation is that my driveway is all slightly uphill. So when I straightened out going forward (coming out of reverse), the blocking solenoid would release which applied full surge brake pressure to the brakes. Then, backing up again, the blocking solenoid would activate and "trap" that pressure in the brake line downstream, thus still applying full brake pressure.
 
Use a volt meter to check. Often it is the purple wire which is the back up rather than the blue (for magnetic brakes). My Yukon works fine with the surge breaks--7 pin to 5 pin adoptor--5th pin locks out the surge brakes and is the back up light circuit.

Google 7 pin connector diagram.
 
Okay.

I know Im not highly tech savvy but I should know how to attach pictures on e-mails. I did get through with 2 college degrees - post computers!! So if anyone can tell me how to attach a pic to this discussion thread I would be indebted.

Also who do I need to ask to create a photo album?

Thank you so much..,

Scott
 
SPrice":21wyjfei said:
Okay.

I know Im not highly tech savvy but I should know how to attach pictures on e-mails. I did get through with 2 college degrees - post computers!! So if anyone can tell me how to attach a pic to this discussion thread I would be indebted.

Also who do I need to ask to create a photo album?

Thank you so much..,

Scott
Click to expand...
Scott - send a private message to either Da Nag (Bill) or Tyboo (Mike) and ask them to set you up with an album.
 
Back
Top