Backing up with surge brakes?

[Pawnshop]

HOW do you back up a M105A3 trailer? The surge brakes keep me from backing up, even a little bit. I have read how to bypass the brakes with a C clamp but there MUST be a built in way to do it, or an adjustment I need to learn. I have been looking for an operators manual but have not found one yet. Anyone out there know the "correct" way???

 

[timntrucks]

i plan on putting in a pin that i can undo for the forward driveing mode on the highway

 

[deuceman51]

LOL, I have a much easier fix than that. I just spent last week fixing this problem on 7 of the SDNGs trailers for one of our units. Just get a piece of 1/4 sheet metal and cut out a rectangle that will fit between the weld on the lunette mount and the collar of the trailer tongue. What we did was mount a small bracket using 2 of the bolts from the master cylinder and I connected the bracket with chain to keep it from getting lost. We painted ours red and put "use when backing" on it. I will try and get some pics of it this week at work for you and some dimensions. I made an extra so I should have a good template. PM me so I don't forget.

 

[Pawnshop]

There is NO way to do it without building an adapter? Where does this previously mentioned pin go?

 

[Nonotagain]

If you use a 1" C clamp on the H beam section it will allow you to back the trailer up.

Installing any mechanism to defeat the surge brakes could yield lots of trouble if you "forget" to remove it prior to going back onto public roads.

By using a small clamp even if you forget to remove it in the event of a panic stop the clamp will slip allowing the brakes to engage.

Here is a pic of the surge brake controller.

I'll post one of the clamp installed later this evening.

 

[NEIOWA]

Anyone have the NSN for the M105A3 surge brake unit? My Fire Dept has some M720 dollys need to acquire and install such so can pull with pickups.

 

[lavarok]

I have several M101A2 and A3 trailers with surge brakes. I've never had an issue just backing up....maybe my surge brakes don't work?

 

[Nonotagain]

Anyone have the NSN for the M105A3 surge brake unit? My Fire Dept has some M720 dollys need to acquire and install such so can pull with pickups.

No NSN number required as the brake activator is made by Titan and is a model 20.

There are a few different #20 models depending on whether it uses a lunette, ball hitch or a drop hitch.

For those that are still having problems backing up on flat surfaces, not hills, the dampeners are probably going bad. The replacement cost is around $40 each and there are two per unit. Look at #17 on this pdf files for the unit.

 

[lavarok]

So is the Tital Model #20 cap on the fluid reservoir a direct fit for the military models? I keep meaning to order one to test it...Titan couldn't confirm when I contacted them previously.

 

[Nonotagain]

So is the Tital Model #20 cap on the fluid reservoir a direct fit for the military models? I keep meaning to order one to test it...Titan couldn't confirm when I contacted them previously.

I can't confirm at this time, though I will be ordering a master cylinder rebuild kit from one of the two placed lsited close to where I work.

The master cylinder listed is 2374400. I can't tell by item description just what exactly comes with the master cylinder kit, but I guess I'll be finding out soon enough.

Easternmarine up in Delaware shows a cap for the 2374400 master cylinder Trailer Parts Superstore - TITAN Model 10 / 20 Actuator Filler Cap for less than $10.

 

[saddamsnightmare]

December 14th, 2009.

Gents:

You are really making me love my M105A2 with whatever minor problems it has with rust, as the Air over Hydraulic brakes work really well. Good luck, but i think the C clamp might just do it for you.

Cheers,

Kyle F. McGrogan

 

[DeuceNewbie]

Dumb question but i am looking to buy a few m105A2'S.......is it possible to back these trailers up? is there any mechanism that keeps it from backing up? also will these trailers function properly if i do not run airlines to it?

we are looking for a few of these to haul brush on a farm and will just be pulling it with a tractor.

 

[Nonotagain]

Dumb question but i am looking to buy a few m105A2'S.......is it possible to back these trailers up? is there any mechanism that keeps it from backing up? also will these trailers function properly if i do not run airlines to it?

we are looking for a few of these to haul brush on a farm and will just be pulling it with a tractor.

The A2 uses air over hydraulic brakes. If you don't apply air to the glad hands you don't have brakes.

So to answer your question, they will back up just fine behind a tractor, just you won't have brakes for stopping.

 

[Pawnshop]

I think my troubles are related to a stubborn parking brake that is not completely disengaging, once I get that taken care of the trailer should back fine.

The advantage to the A3s surge braking system is that you don't need air to make the brakes work. When I am pulling it behind my M1009 (empty only, just shagging it around town) the trailer will do it's own braking, and I like that.

 

[tanglediver]

While I have zero experience with any M-series trailers, what we like to do with civilian surge brakes is to use a backup solenoid. Adapting one would take a bit of homework, but the idea is to attach an inline solenoid that defeats the brake pressure when given voltage from the tow vehicles backup light circuit.

Edit:- The solenoid is usually not needed with drum brakes, but with disc brakes, it becomes essential.

 

[NEIOWA]

No NSN number required as the brake activator is made by Titan and is a model 20.

There are a few different #20 models depending on whether it uses a lunette, ball hitch or a drop hitch.

For those that are still having problems backing up on flat surfaces, not hills, the dampeners are probably going bad. The replacement cost is around $40 each and there are two per unit. Look at #17 on this pdf files for the unit.

To locate/obtain thru the DOD parts channel need an NSN (I use DRMS for our Fire Dept).

 

[RJM27]

go ahead and back up

I agree w/ the parking brake conclusion. I have used my m101A2 on and off road, loaded to the max(springs flat and slightly turned down) at first had problems backing up, until I adjusted the brakes. I'm amazed at how well the surge brakes work, especially going down 10% grade in the woods loaded with gravel. By the way these trailers are fantastic dump trailers as well.