M809-series (M818) Air Brake Retrofit

[rangereter]

Being in a very "road salt" environment, I appreciate the ease of maintenance of outboard drum s-cam brakes...but I also really like the stopping power of the Rockwell Stopmaster wedge air-brakes when heavily loaded.
Regards, Bob

 

[MyothersanM1]

My neighbor and I went to the storage yard and removed all the hub/drums with out any issues. I brought them to the house to do the drum conversion.

I unbolted all the old drums and set them aside. They're not so dang heavy when not married up to those hubs.

After removing the drums, I popped out the inner seals, took out the inner bearings and did a preliminary wipe down/cleaning of the insides of the hubs. I'll degrease the bearings tomorrow or later next week once I get some more degreaser.

The new set-up will use a longer stud that came with the kit. The new studs are long enough to reach through the brake drum and the hub flange. So, I removed old studs from one hub before calling it a day.

Sorry for only one pic. My hands have been either greasy or full of dirt from a simultaneous garden project all day. I didn't want to muck up the camera.

 

[Bandit02]

The kit came with an R-12V and two QR-1's valves. I won't be using the QR-1's as I'm following the diagram I posted earlier which uses the R-14 and the SR-1 spring brake valve. Yeah, I wouldn't mess too much with your truck's plumbing. The air may route differently, but all arrives at the cans the same.

I take it the wedges you battled with were not well maintained? Luckily the M939-series backing plates are two piece for easy removal. I tell you, once I find a viable s-cam set-up for the fronts, I will switch.

You know, 2 piece backing plates make all the difference.

Make sure you put a good coat of anti-sieze of those bolts. extracting broken backing plate bolts on a spider is one job that I dislike alot haha.

 

[MyothersanM1]

Finished up the stud removal this early evening. Wasn't to bad. I used a drill hammer and they all came out fairly easy.

 

[wcuhillbilly]

Im thinkin this is STICKY WORTHY when he gets this all finished up. Who agrees??????


GREAT JOB

 

[Tow4]

What is in the kit you speak of the has the longer studs?

 

[MyothersanM1]

With this kit you must use the existing hub. In it's original form, the m39-series and M809-series hub bolts to the drum via an adapter plate that bolts to the outer edge of the drum. You can see those hub bolts (they are the same pattern and size as that of the axle flange) which are just outside the inner seal in the pic a few posts above. The original studs only attach to the hub flange.

Now, with the new drum, the hub attaches outboard of the drum utilizing the studs. Hence, the studs have a longer shoulder to fit through both the inner side of the drum and the hub flange. The new studs are provided loose in the kit and must be installed. I will post pics of the difference in length later today.

 

[MyothersanM1]

Another side note...the this particular drum/hub modification will NOT work with "flipped" hubs. The new brake drum has nothing to attach to in the flipped hub configuration.

 

[Bandit02]

Could you slide the drum over from the outside or they not long enough to cover the shoe properly?

[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]Those new drums you got in your kit look like Dayton bolt-on drums. I wonder, if by chance you had a standard 16.5" steel drum used on today's s-cam equipped trucks; would it slide on?! Then you have outboard drums and that would make your life amazing come brake maintenance. [/FONT]

 

[MyothersanM1]

Here's length comparison of the old studs to the new. The old measure (from under the head) 2 13/16" and the new measure 3 3/8".

Could you slide the drum over from the outside or they not long enough to cover the shoe properly?

Those new drums you got in your kit look like Dayton bolt-on drums. I wonder, if by chance you had a standard 16.5" steel drum used on today's s-cam equipped trucks; would it slide on?! Then you have outboard drums and that would make your life amazing come brake maintenance.

The drums mount inboard to the hub flange. If slid on outboard they would not cover the shoes completely. So, sadly I won't be able to enjoy that convenience. Maybe someday someone will come up with that set up and, again, my wallet will open wide Here's a pic of a very similar brake kit installation and what mine will look somewhat like. At center/left you can see the edge of the shoe flush with the drum. I believe the photo credit goes to Brother OPCOM http://www.bunkerofdoom.com/travel/steelsoldiers4/20080929_memphis/index.html

 

[Bandit02]

Hmmm, well auto slacks were a good choice as it looks pretty tight to go in there and adjust periodically with manuals.

I understand what you mean about the drums not covering the shoes completely if mounted outboard. That setup in your pic looks 100% to me like a Dayton drum, which IIRC only measure about 10.6" or so in overall depth.

I was thinking of using a 16.5x8.62 drum as they are 10x11.2 bolt circle, 8.78" pilot and they have a 11.12" depth, which may be enough to cover the shoe. The part number is for that is Gunite Gold 9019X, also crosses to Standard Gunite 3807X, Meritor 53-123581-002, Webb 66854B and Hayes Lemmerz 90486B.

Oh, one more thing. Look at the pushrod to slack relation in that pic. When your park brake is applied the relation should be 90* max, that one is way over and eventually could cause a over-cam situation where the pushrod binds on the slack from the clevis hitting it (very dangerous). Even with a auto slack that can happen. They didn't cut the rod down enough.

Here's Haldex's literature about doing it properly: http://www.haldex.com/en/north-amer...s_and_Manual_Brake_Adjusters)_L58002_6-07.pdf

One day, with enough research I'm going to find the cure for the outboard drum for this setup. I will share that info with all my brothers & sisters on here when I do.

 

[MyothersanM1]

Oh, one more thing. Look at the pushrod to slack relation in that pic. When your park brake is applied the relation should be 90* max, that one is way over and eventually could cause a over-cam situation where the pushrod binds on the slack from the clevis hitting it (very dangerous). Even with a auto slack that can happen. They didn't cut the rod down enough.

Yeah, I dialed in that when I first found these pics a couple of weeks ago. Anything less than 90 is no bueno! I have the same push rod cutting instructions. Here...I have loaded them directly into the post.

View attachment Spring_Brake-Push_Rod_Cutting_(Automatic_Brake_Adjusters_and_Manual_Brake_Adjusters)_L58002_6-07.pdf

I've already marked the 90 degree point on my push rods. My auto slacks came in today. I just need to double check the clevis depth, make the additional marks and cut.

 

[MyothersanM1]

I have been working on removing the original backing plates. It has been slow going as I do not have a large industrial strength frame drill. I have drilled out two backing plates so far from the rear most axle. I have been using a 1/2" drill starting with a 3/16" pilot then working up by a 1/16th to 1/2". By that point, you can beat it out with a chisel and hammer. You guys with M939-series trucks don't have to worry. Your wedge brake spider are bolted on the axle. I can only wish these were bolted.



I have dry fit two spiders and and cam tubes. They just need to be torqued down. I have decided to hang the air chambers pointing down away from the frame for clearance when the axles articulate. Referring back to the parts list earlier in this thread, this is the how they are monting to the axles...
-R/H Spider 3819P + L/H Cam tube 1552 will mount to right/front and left/rear
-L/H Spider 3818P + R/H Cam tube 1553 will mount to left/front and right/rear

 

[MyothersanM1]

Later this afternoon, I cut the air chamber actuating rods to the proper length for my set up now that I have my automatic slack adjusters. I needed the clevis depth dimension for an accurate cut. Rather than get wordy about the task, I have reposted a Haldex worksheet that spells out this procedure. It's not to complicated, you just need all the components in one place to ensure your measurements are correct.


View attachment Spring_Brake-Push_Rod_Cutting_(Automatic_Brake_Adjusters_and_Manual_Brake_Adjusters)_L58002_6-07.pdf

 

[MyothersanM1]

I finally got all the old backing plates plates off. That's 40, four-zero, 9/16" rivets drilled and reamed out! SO glad that's done!

Anyway, moving right along! All four brake sets (spiders, s-cam tubes/brackets, s-cams, shoes, springs and air chambers) are now installed less the slack adjusters.



I first installed the spiders and cam brackets using the 9/16"-18 X 1 3/4" fine thread bolts and lock-nuts provided. I just torqued them down with 1/2" impact wrench. No difficulties here. Just a pretty straight forward job.

The brake shoes and s-cams were next.
First, I did some pre-assembling on the brake shoes. The "flat vee" shaped return spring hanging clips, included in the brake shoe kits that return springs hook on to, need to be installed with a hammer. Just set them through one hole on one of the brake shoe ribs lining up the other end of the clip with the opposite rib hole. Give the long end sticking out a good whack and the clip will seat loosely between the ribs.



Second, after installing the clips, I installed the s-cam rollers. I put a light coating of clay-based grease on the moving surfaces then installed the retaining clips. Setting the rollers in the corresponding round notches, I squeezed and pushed in the retaining clips until they seated in the two wholes just below the roller notches. Make sure the round end of the clip is facing outward from the shoe once installed.



Third, I installed the s-cams ensuring that right and left orienting was observed. If you don't the cams will not actuate the brakes. There is a large washer that must be installed between the cam and the tube opening. The cams just slide right into the tubes with the "s" fully seated against the washer which is seated against the tube. Now, the shoes can be installed.

 

[MyothersanM1]

Fourth, I installed the anchor pins using a light coating of anti-seize. The pins slide easily into their holes and will move freely back forth until the shoes are installed. The pins are locked into place once the brake shoes are set in place. I set the top shoe on the top anchor pin and let its roller rest against the s-cam on the other side. The bottom shoe is installed hinged all the back as if installed reversed setting on the bottom anchor pin. The black anchor springs are installed on either side ensuring their hooks are fully seated in their holes. I then rotated the bottom shoe back around to its normal position seating its roller in the s-cam. The anchor springs will hold the lower shoe in place for return spring install.



Lastly, I installed the return spring. I used a brake spring installation tool for this...
http://www.ryderfleetproducts.com/brake-tech-tools-105-1sp/brake-spring-removal-tool-p-btt-1051sp
The tool is inserted between the shoe ribs and the s-cam roller. I hooked the spring to the bottom clip and to the tool with the spring hook facing toward the upper clip. A little downward pressure and pull back on the tool and the spring hooks to the top clip. The brake shoes are now installed.



I installed the air chamber now that the push rods are cut. The mounting hole on the s-cam brackets have two settings. The outer most setting is used. The air chamber studs are inserted into the mounting hole ensuring the the service and emergency ports face inboard. Install lock washers and 5/8" nuts and tighten it all up with a 15/16" wrench.

 

[MyothersanM1]

I took some air chamber mounting pics this afternoon to continue the end of my last post. I have highlighted the proper bolting orientation with the circle and arrow (Arlo Guthrie would be proud ).

 

[MyothersanM1]

I am not going to elaborate on bearings and seals service (excellent write up here http://www.steelsoldiers.com/showthread.php?57099-5-ton-rear-axle-seal-fix-procedure) in this thread, but I thought I would address the wiper ring (AKA speedy sleeve) service.

I removed the old and installed four new wiper rings. I used the remove/install method in post #2 here http://www.steelsoldiers.com/showthread.php?81271-inner-seal-wiper
I used a cold chisel and hammer to "crease" the old ring which stretches the ring out. After several taps (tap it moderately hard, it won't ruin the axle) they slide right off with minimal coaxing. I used a little white lithium grease I had in the on-board tool box to lube up the install. After setting the ring on hand tight, I tapped around the outside edge lightly with my trusty bell peen to set it a little further. Then I used the 4" PVC pipe and coupling (from McMaster-Carr) to drive it home.





I mounted up the the new brake drums to the hubs. That was a bit of a job driving in 40 new studs. I used both air impact and drill hammer. The drum does not have an adapter ring like the original drums which the hub bolts to. The hub on these drums attaches directly through the studs. I also put in the cleaned and repacked inner bearings and new inner seals. Luckily, I had a nice length of 6" PVC from a model railroad project. I cut a piece to use as a seal driver and it worked flawlessly.

 

[MyothersanM1]

Alright, I'm back. I kept forgetting to take my camera over to the storage yard to get progress pics, but I remebered today.

Last weekend, with the help of my father-in-law, I was able to get the hubs/new drums assemblies and axles back on to truck. I only put the amidships axle's inner tires on. The rear axle had to dropped down in order to attach the rear relay valve assembly (remember the "turret") so I left those tires off.


I put two jackstands under the trunnion tube. I then jacked the amidships axle up to the stops and held it in place with another jackstand. This gave me enough, not plenty, room to crawl between the rear axle and frame in order to bolt up the rear relay assembly. I drilled out the center crossmember, then attached the relay assembly.


After getting the relays in, I began to plumb the air lines. The balance loop was simple as it only required a short piece of 3/8" tubing from the spring brake relay to the service. All other tubing, 5/8" service brake supply, 1/2" spring brake supply and 1/2" for both relays service connections were run along the left frame up to under the cab just forward of the air tanks. The spring service line was terminated at the SR1 spring brake valve. I also connected all the air chamber delivery hose (SAE J1402A) with spring guard fittings to the service and spring brake relays. I left these unattached at the air chambers until I finished the slack adjuster install.

I chose to put the SR1 valve in an area protected from grease spatter. I don't want this valve getting all fouled up as it crucial in the emergency actuation of the spring brakes. The crossmember just above and to the rear of the hand brake is a relatively clean location.

 

[MyothersanM1]

I set the clevis on the air chambers for optimum slack adjuster operation using special templates supplied by Meritor. The instructions are on page 15 and 16 in this technical manual...
View attachment Automatic Slack Adjusters.pdf

I went to install the premium Meritor automatic slack adjusters I had bought thinking it would be a straight forward job. Uh, No! The position the spiders and cam brackets are clocked at hinder the these slack adjusters going to full stroke. The lower torque rod seats interfere with the slack adjuster's squared off back side. I cured this by taking out the inner bolts on the torque rod seats then grinding out some clearance room.


Once I did the grinding, the slack adjusters were able to travel full stroke. I place the slack adjusters on the s-cam spline shaft, installed shim washers as needed then sealed it up with the snap ring. The handy slack adjuster tool set I bought came with a special ratchet for moving the slack adjuster back and forth while installed. Well, now the clearances are to tight to use it. The pawl release tool works fine. My closed end 3/8" ratchet wrench was able to get in there and it worked flawlessly. I bought an extra one at Home Depot to keep on the truck.


I attached the slack adjusters with the air chambers removed. It easier as there is nothing in the way. Once the slack adjusters were in place I bolted the air chambers back up.

I moved the slack adjuster into the proper position lining up the clevis on the air chamber with clevis pin holes on the slack adjuster using the wrench to turn the small adjusting nut at the bottom of the slack adjuster. I applied a light coat of anti-seize to the clevis pins and installed them locking them in with cotter pins. The clevis pin for the adjusting pawl is a little tricky, but not difficult. The adjusting pawl link has spring tension in it so you have to pull it up to line up with the clevis pins holes.


After the slack adjusters were installed, I connected up the air brake hoses on the amidships axles. I left the rear disconnected as I am going to install the fittings on the rear air chambers using some 45º street elbows. I will also be fabricating some brackets with rubber clamps to route the hoses up and over the axles and to keep them dressed up and out of the way of moving parts.