School me on Surge Brakes

[hwcurtice]

While I'm waiting for my SF-97 and plates, getting the wiring done and all, I want to do some really work on the braking system on this trailer.

So, how do the surge brakes work?

What should I look for in the ways of damage or needs for concern?

Because I really haven't looked under the trailer yet, are these disc or drum?
Where can I find replacement pads or shoes, if needed?

Don't laugh, if need be, can the brakes be worked on by any brake shop or do I need to hunt down someone from the forum in my area to laugh at me while I make mistakes?

Oh yeah, it's a 1990 Kasel M101a2 3/4 Ton.

 

[steelandcanvas]

Upon stopping or slowing down, the forward motion of the trailer pushes against the lunette, pushing a piston in a cylinder which in turn pushes brake fluid to the wheel cylinders. It has drum style brakes, and anybody who knows brakes can work on it.

 

[FireFighterHill]

there is also a shock that helps regulate how fast the brakes engaged so there isnt alot of jerkiness. The lunette is suspended by 4 bars and 8 bolts and bushings. The bolts and bushings can become seized if that happens you have no brakes. The Master cylinder is from a 60era jeep.

 

[rosco]

The system uses DOT 5 brake fluid. Don't mix the stuff with DOT 3 that is more commonly used. There is a brake lock out hole in the surge system. By inserting a pin in it, it allows you to back it up, as in "up" an incline, or in sand/mud, with out the brakes being applied at the same time, thus working against you.

 

[73m819]

Now this is what I call a VERY useful thread for a NEW MENBER, no read the TMs, or before you buy read, search, ect. THANK YOU

 

[hwcurtice]

Now this is what I call a VERY useful thread for a NEW MENBER, no read the TMs, or before you buy read, search, ect. THANK YOU

Yeah, that helps...

Just went through the TMs (I dispise acronyms) Not a single mention of, as far as I can tell, a M101a2 trailer in there.

So, yes, this thread is very helpful. It might get all this information I need to work on my trailer in one spot instead of all over, like a naval bombardment would be....

I did know about the pin through the hole before I went to pick the trailer up, which helped as I was backing into my driveway. I knew about the shock that is in there, but I didn't know about a master cylinder or fluid, nor how the system works.

So, I will keep notes on all the useful information I have found, and discard the non-useful, and make my trailer work for me.

 

[KsM715]

Its a pdf file.right click and save it to a disc or your hard drive.

 

[gunboy1656]

Well normally I would say find it in the TM's, but in this case it was asking about the theory about how a part works, which usually they don't cover.

And hwcurtice, you despise acronyms, but yet collect military stuff? the mil loves to use them for everything.

 

[steelypip]

One thing I'd add - when pulling a loaded trailer with surge brakes in the mountains it is good to modify your driving technique a little to accommodate the way the system works.

With no trailer brakes, you try to keep your speed down to a consistent and manageable level for the upcoming conditions at all times because you have limited ability to control the trailer.

With remote trailer brakes (as used on RV trailers, etc), it's common to actuate the trailer brakes before the vehicle brakes to reduce the possibility of the tail wagging the dog. It can be a very convenient way to yank the rear of the tow vehicle back into line if something starts to come around, and it means that the tow vehicle brakes are cool and responsive if you need to do something sudden.

With surge brakes, you can also use the trailer brakes actively, but you have to do so in a straight line. In the mountains of Pennsylvania (US 219) pulling ~2500 lbs of two-axle box trailer with surge brakes, I very purposefully would line the rig up on a straight section, let it speed up to a little past my comfort zone, then fairly aggressively brake the tow vehicle. The 2000 lbs of cargo did a fine job of forcing a fairly hard engagement of the surge brakes. When I felt them dig in, I would back off the tow vehicle brakes to a fairly gentle slowing and let the trailer brakes do most of the work. I would enter the next turn at a good bit below my max comfort speed with plenty of additional braking available from the tow vehicle. This left me a lot of braking reserve capacity on the tow vehicle and meant that if I had to do a panic stop in a straight line the trailer brakes were already somewhat engaged and would respond instantly and consistently.

You have to resist the temptation to brake while turning when using surge brakes - at some point the traction limit of pushing the tow vehicle sideways is less than the brake engage limit of the trailer brakes. You don't want to find out what that point is.

 

[hwcurtice]

Well normally I would say find it in the TM's, but in this case it was asking about the theory about how a part works, which usually they don't cover.

And hwcurtice, you despise acronyms, but yet collect military stuff? the mil loves to use them for everything.

This is my first item of military nature, so I would not consider myself a collector, just yet.

My wonderful wife brings acronyms home from work all the time. Bugs the crap out of me. She doesn't undersatnd the 'Deer caught in headlights' look I get when she does this...

 

[Green_gator]

The spare parts for the surge brake system are available from Toledo Actuators, but are not cheap. Here is their website. You can push in on the lunette and determine easily if the shock is still functional.
Toledo Actuators | Balcrank Products Inc. Customer Service 800-747-5300 Fax 800-763-0840
Four bolts hold the coupler to the frame, the rear two have nuts attached and the forward two bolt into the coupler using fine thread bolts. There should be a break away chain attached at the top of the coupler to forcibly engage the brakes if the trailer separates from the tow vehicle.

 

[steelandcanvas]

Now this is what I call a VERY useful thread for a NEW MENBER, no read the TMs, or before you buy read, search, ect. THANK YOU

The Gentleman didn't come across as a "know it all", so it was my pleasure to explain (what I know) a little surge brake theory to him. Besides, I'm turning over a new leaf, I'm going to be nice to newbies from now on.

 

[Lifer]

And hwcurtice, you despise acronyms, but yet collect military stuff? the mil loves to use them for everything.

Anyone who has ever served in the armed forces knows that they would be FUBAR without acronyms! In your case you'd better get familiar with them ASAP or you'll be in deep kimchee*.

* That's another thing GIs are famous for...snippets of other languages tossed into normal everyday conversations. Don't ya just love it?

 

[gunboy1656]

Never had kimchee, and from what I have heard I don't intend on trying it.

There was a post I saw a while ago that listed some of the acronyms for those who never served, but could not find it.

 

[hwcurtice]

Anyone who has ever served in the armed forces knows that they would be FUBAR without acronyms! In your case you'd better get familiar with them ASAP or you'll be in deep kimchee*.

* That's another thing GIs are famous for...snippets of other languages tossed into normal everyday conversations. Don't ya just love it?

And you know, if it wasn't for GIs, we'd be speaking languages other than English. So, I suppose I shouldn't complain too much.

BTW, I was never honored enough to serve. But my father, my brother, my brother-in-law, my sister and her husband, and one of her daughters all served. In fact, her daughter is still in the Air Force. Quite a group. My brother retired as a Command Master Sergant. He interviewed for Sergant of the Army, but I don't know how that turned out...

 

[MWMULES]

When you pick up your trailer from GL makes sure the break away paw is all the way down, no notches showing. I had a newbie buddy get one and it was just one notch up, it took about 40 miles on the interstate before it locked it up and burnt one of the shoes.

 

[LuckyDog]

Anyone who has ever served in the armed forces knows that they would be FUBAR without acronyms! In your case you'd better get familiar with them ASAP or you'll be in deep kimchee*.

* That's another thing GIs are famous for...snippets of other languages tossed into normal everyday conversations. Don't ya just love it?

Here is a link to the OFFICIAL DOD dictionary. Don't download and print: its 695 pages.

DOD Dictionary of Military and Associated Terms

AND: since it from the Guberment, GI and FUBAR ain't in thar.

ASAP is: As soon as possible. Now riddle me this: Why does my boss use ASAP to mean RTFN! (and that ain't "Read The Freakin' Notice")

Whiskey Tango Foxtrot Over

 

[steelandcanvas]

* That's another thing GIs are famous for...snippets of other languages tossed into normal everyday conversations. Don't ya just love it?

Beaucoup (pronounced boocoo) is another one that comes to mind.

 

[RJM27]

the system uses dot 5 brake fluid. Don't mix the stuff with dot 3 that is more commonly used. There is a brake lock out hole in the surge system. By inserting a pin in it, it allows you to back it up, as in "up" an incline, or in sand/mud, with out the brakes being applied at the same time, thus working against you.

why dot 5 not 3 ???????????