M105 Trailer Recovery - Brakes on Fire

[ecostruction]

Slight problem while recovering a pristine M105 this week at Mechanicsburg. Hooked up fine to one of my Deuce's. I was actually able to maneuver the trailer by hand from behind abother trailer out to the drive to hook it up. No help needed. Everything seemed fine. The new LED lights worked. Everything seemed to work fine. Front landing gear swivled almost too easily. Everything was going great and looked like I would be able to make my holiday lunch at noon. Or so I thought.

About 6 miles from home the truck started loosing power on the highway (I 83). I was going up a hill, so didn't think too much of it. This particular truck while great on the flat, gets lost going up the slightest grade with the slightest load. Even an empty 105. Anyway, topped the hill and started down the other side but couldn't get any speed, so knew something was up and pulled over. Luckily I was able to hit the grassy area next to a wide shoulder of a long offramp. So was not too close to the main travel lanes. As soon as I came to a stop, I saw a bunch of smoke coming from the back end. Oh crap!!! Hoped out and the smoke was coming from the brakes of both sides of the trailer wheels. Didn't know quite what to do, so unhooked the air and tried to move it further off the road, but now everything was really locked up. Just dragged the trailer about 25 feet to get it in a better spot. Got out of the truck and went back to the trailer to look under. Now the right side (passenger) caught fire. Not bad, just some little flames, but oh crap!!! I have a fire extinguisher, but thought I couldn't get to it (another long story) so started trying to flag someone down. One of the major construction outfits has a yard right next to where I was stopped and I was trying to flag one of the employees down to get an extinguisher. No luck. Went back to check on the fire and it had gone out on it's own. PHEW.... So now what? Well, I called my faithful backup (aka: dad) who is long retired and happened to be sick and I ended up unhooking the 105 at the spot and going home with the deuce to grab another construction trailer that i just bought. It's not adapted to the deuce yet, so I had to park the deuce.

We weren't sure how to get a 105 onto the construction trailer when the 105 had frozen wheels/hubs/brakes. We had a cable puller, but those things aren't all that strong. So decided my dad would drive the suburban with the trailer and I would take my LR Disco II with a 12k lb winch and might be able to winch it on with the rover. I thought I would have enough room on the off ramp to do a 3 point turn against flow of traffic to load the trailer. So we headed out. Oh, the construction trailer is not mated to the rover yet. When I hit the brakes in the rover, the trailer brakes lock up.

When we got back to the trailer, everything was done smoking, but things were still hot. BUT, we could wheel the trailer by hand again. The wheels were not frozen. That was amazing. As cooked as everything was, I though sure they would be looked until I took everything apart. So that made getting it on the other trailer that much easier. Which it was considering my dad was sick and I had to do it all by hand with the cable puller (didn't want to maneuver the rover if I didn't have to for saftey reasons). Chained and strapped it down and headed home (but still missed my lunch). We decided to still load it in case it happened again and we weren't in a great spot to pull over.

Now we needed to get it off the trailer, again by hand. This is where my JD 350B crawler loader would have come in handy, but it's at another spot. So we were left to get it off by hand. Ultimately I decided to exercise the winch on the rover and it winched it down just fine.

Pics attached of some of the recovery including the chared hubs/wheels on the inside. It is a shame because this thing was rebuilt in '06 and never saw service. Now it's got charred wheels on the inside and who knows what kind of damage. Any thoughts on that? Will take everything apart in due time to see what happened. I can't think of why it would roll by hand then lock up. Not sure how I could have avoided this since everything seemed fine. Crap happens I guess. At least the fire went out and didn't do any damage to the tires. Those on fire adds a whole new dimension to this event.

 

[Recovry4x4]

The problem you experienced is a common one. The relay valve has failed and applied the brakes gradually while driving. Once the air bled off after unhooking the truck, the brakes free up. Don't hook up the air lines until you replace your relay valve. Any big truck shop or air brake shop should be able to match one up. In the future, releasing the trailer air (by draining tank on the trailer after unhooking air lines) will free up the trailer and have you back on the road in no time.

 

[m35tech]

wow , so what happend, bad brakes, sieze up, glad your ok, hows the trailer now

 

[emmado22]

The relay valves go bad FREQUENTLY from lack of use... .... I wrote a post on my M105A2's brakes and it's bad relay valve.. Has the part # you'll need for a new valve... Looks like you just burnt the paint off the drums... I saw it happen a few times in the Army.. Pull the hubs, see if there is more damage than burnt paint.
Good luck

 

[ems4ty]

ecostruction,

Always check your wheel hubs after the first 5 to 10 minutes of travel, and then again later on. That being said, I had a similar issue with my 105 trailer. Hooked up the service line on the deuce and took a drive down the freeweay. When I got off the freeway and parked I thought to check the axles and brakes. When I got to the trailer, the hubs were burning up and could smell the brake linings cook a bit. I unhooked the air line but there was no pressure. So, I grabbed a crescent wrench and went for the bleeder valve on the brake cylinder and wouldn't you know it, a steady stream of fluid shot out. (I just flushed the brakes with new DOT 5 Silicone fluid before this little trip.)

Now, I never got around to figuring out what the deal was. I wanted to know why the brakes would drag or be under pressure when there was no air in the glad hand line. Kinda seems like the master cylinder on the trailer had failed or was sticking. I mean, all that is back there is a diaphram that pushes on the master cylinder. Can't be that complicated. Anyways, I never took it apart to check it out. I pretty much always towed the trailer empty so there was never a real need for the trailer brakes in my opinion. I'd still hookup the air line to the service valve (Drivers side of the truck) but keep the valve closed. That way if I ever got stopped by Highway Patrol when in tow, it looked like they were connected.

Good luck to you and be sure to check the hubs frequently when in transit until you know you don't have any problems anymore.

-Tyler

 

[ems4ty]

emmado22,

When you say the relay valve, are you talking about the diaphram looking assembly that is bolted directly to the Brake Master Cylinder on the Trailer? (I Call it a diaphram just because I didn't know what else to call it...)

Thanks,

-Tyler

 

[Scrounger]

There are two types of systems on the 105 trailer. The early systems use one air line and the later uses two. The first uses the service line to operate a diaphragm that operates the master cylinder. The later type has an emergency side and a service side. The emergency side charges an air tank and the service side goes to a trailer relay control valve. Unlike the early system the later system operates by having air from the service line operate the diaphragm/ master cylinder thru the relay control valve. The advantage of this system is if the air pressure drops below a certain level the brakes will be applied with the air that remains in the air tank. One of the purposes of this is if in the event the trailer was to some how come unhooked from the tow vehicle the brakes will come on automatically. While the second system meets the “new” DOT rules it does have its problems. It complicates what was a simple system and I really don’t see the need for it.
Now as far as what may have happened to your trailer, the relay control valve may have failed. Or maybe the service side of your deuce may have sent air to the trailer when you applied the brakes and it didn’t bleed off. That would allow the brake to drag. I have a 5 ton that does that. I haven’t had the time to figure out why.

 

[emmado22]

I dont know whats wrong with your trailer, but do this. The relay valve is in the pictures.. http://www.steelsoldiers.com/showthread.php?t=20000&highlight=m105a2+brakes Read the thread, I posted what I found and how to fix it. It may not be your problem, but it sure wont hurt anything to follow what I posted.

First, check the brake fluid in the MC.. Should be filled to the brim with DOT 5.
Next, check your relay valve by hooking up the truck to the trailer, open the air valves on the back of the deuce, and have one guy hit the brakes, and the other listens for relay valve operation. When first connected, the air tank on the trailer should fill with air. Hit the brakes on the truck. the brakes on the trailer should operate.. Make sure they release fully. Jack up one side of the trailer to do this.. Spin the wheel, then hit the brakes.. The wheel should stop instantly. Not "roll" to a stop.. Check both sides.


The diaphram looking thing is called an actuator pancake. Make sure the rubber disk inside it isnt ripped. Make sure there is no crap in the whole assembly and the rubber can freely move when the brakes are applied.. Rocks, dirt, etc will impede it's function.

The relay valves go bad from lack of use. Some old time mechanics say to hit it with a hammer to loosen stuck parts up.. I'd rather unhook some air hoses to it, and squirt some air tool oil in there...

Also, check the air filters on the trailer itself.. There are 2. (very little known fact)
They are located where the air lines "meet" the cross member on the frame.. Unscrew the bottoms of them, remove the guts, clean, and reassemble.. It's in the TM..

Make sure your air lines are all clear. Mud wasps love to make homes in the air lines, this isnt good. Blow out all the lines when the air filters are off.. wiggle them while you blow them out with high pressure air to get any stuff out.

One thing to check for on airbrake trailers is that the glad hands are colored correctly.. I have seen the emergency gladhand colored yellow and the service one colored red because someone didnt think there was a difference and just shot some paint on them without looking at the TM to see which is which.

Let me know if you need more help.

 

[KaiserM109]

The problem you experienced is a common one. The relay valve has failed and applied the brakes gradually while driving. ...

There are two types of systems on the 105 trailer. The early systems use one air line and the later uses two. ...

Recovery4x4 would be right on except that econstruction has the early type with no relay valve.

The fastest way to tell them apart in the pic's is the presence or lack of the lifting lugs with 2 holes each welded to the frame just in front of the box. also, if the pic' is clear enough, there is a second air line stowed in front of the electric line on the left side.

This might help:

 

[emmado22]

Eco's trailer DOES have the relay valve. You can see 2 air lines (blue and red) in the pictures he has posted. The presence of the lifting lugs is not a sure fire way to tell old "1 line" vs newer "2 line" air systems, as over the years, rebuilds and the smart thinking military mechanic has retrofitted the 2 line sytem onto older 1 line trailers, chassis swaps have happened, etc

I also have reason to belive his trailer was recently manufactured right from Pribbs..

 

[ems4ty]

KaiserM109 - HAHA - Love the use of that great pic - Very Funny

I have a early version trailer with no Relay and single air line. The brakes on that trailer dragged on one occasion and haven't used them since. I think it's a problem with the Actuator Pancake as Emmado22 called it. I never got around to pulling it out and getting a new. Visually, it looks like its about time to be replaced. The MC probably could use a rebuild (IE. New seals) but never had the MC Leak. Oh well. Too cold outside to do anything about it anyways.

Thanks for the info,

-Tyler

 

[wsucougarx]

Wow very nice trailer!!! Great catch

 

[MilitaryRestoration]

I have a 5 ton that does that. I haven’t had the time to figure out why.

All 5tons I've driven do this as well as all the ones my buddy has had. Have gone through the complete systems and can't find a solution. So what we do is crack the service line valve on the back of the truck (by tail lights, when pulling a trailer) this allows just enough air to escape, stopping it from getting backed up. This happened to my just recently... driving into the neighbor hood and going about 20, truck comes to an instant complete stop and truck would not move at all. So thinking it was trailer brakes and not able to get them free'd we went to unhook from trailer and couldn't even do that. Come to find out the truck brakes along with... the trailer brakes were all locked up. Normally I crack that service valve but I forgot to this time and I noticed so went over and opened it up and was like opening a pressurized air compressor tank. But instantly the whole truck and trailer started rolling. Can't seem to figure it out, others have had same problem and can't either... Anyone else got any suggestions since we are on the braking topic ?

 

[ecostruction]

I did check the hubs and everything about 5 miles and again at about 10 miles from base. Everything was good. But, what emmado posts seems like what happened. I'll tear into it in the coming weeks and let you know what I find. After posting, i remembered reading about the relay valve on these things and figured that's what happened. Thanks for all the suggestions.

 

[emmado22]

Eco, PM me with your email. I have something that may help you...

 

[KaiserM109]

I stand corrected. I see the hoses, but I don't see the bracket in front of the electrical bracket for the blue hose. Maybe that is why the blue hose is hanging down.

In that case I have to endorse what Recovery4x4 said. If you need help, these folks sent me some used but FREE wasp excluders for 3 of my trailers that were damaged: (clipped from http://old.steelsoldiers.com/index....pic&t=15404&postdays=0&postorder=asc&start=40 :

I want to plug www.airbrakespec.com for being helpful and generous. They deal with all kinds of valves, including the ones that come on the M105s

If you need a valve replaced or overhauled, I would recommend that you talk to these folks first.

Arlyn
Colorado

 

[shenkmen]

Since I'm the new owner of this trailer with the "brakes grabbed a little" issue I'll add the solution to the thread.

It definitely needed a new relay valve. The Midland part number is KN30300X and is available from NAPA - NAPA AUTO PARTS

The bottom of the relay valve (see image #4) has four air line attachment ports. Only one is needed. The existing relay valve used allen head plugs for the unused ports. I used external hex head plugs. These plugs are in picture #1. The port which is not plugged came with a 90 degree fitting and was replaced with the same. Two straight air line fittings which thread into the side of the relay valve are required as well.

I used air line fittings which thread into the relay valve with push lock fittings on the air line side. The push lock fittings allowed me to reuse the existing air lines by cutting the end of the lines / compression rings off. The push lock fittings are a bit longer so that allowed the cutting. Two straight push lock fittings(picture #2) and one 90 degree push fitting (picture #3) were used.

Teflon tape was applied to all of the brass threads. I used a mini pipe cutter (picture 6). The pipe cutter was used to score the plastic(?) airlines. I cut the rest of the way through with a utility knife. The rule with using a cutter is to 1) tighten the cutter to contact then 2) rotate 180 degrees forward then 3) rotate 180 degrees back and start over at step #1.

Pictures 4 and 5 show the bottom and top of the old and new relay valves.

I removed, inspected and reinstalled the drums and bearings on both sides while inspecting the shoes and brake internals. Last, I lubed all points as per the LO.

Enjoy. Thanks to SteelSoldiers.

 

[fasttruck]

For those with m809 trucks where the brakes drag with or without trailer: when this happens remove the dummy coupler from the front emergency air connection behind the bumper. If air comes out and the brakes then release the vent on this coupler is inop and not allowing air to vent to atmosphere when brake is released thus it drags. obviously put the hand brake on or chock the vehicle so it does not roll away if the brake releases.

 

[davey8943]

Pictures 4 and 5 show the bottom and top of the old and new relay valves.

They also show you have pretty good taste in beer!

I liked the Amish Four Grain the best, but the milk stout was a close second...



Dave

 

[brasco]

Does anyone know how this story ended? Were the brakes completly toast? How much had to be rebuilt or replaced, if any?

My recent recovery had similar results. I don't think my brakes got quite as hot but they were really smoking for a while.