Lube S Cams

[jimbo2013]

Anyone have the steps needed, I thought the drums had to be removed to get them.

[Skip426]

That was my understanding too.
There should be a grease fitting for the shaft 1/2 way between the auto slack adjuster and the S cam. Other than that I can't think of a way to lube the cams themselves that wouldn't contaminate the brake linings , if the drums were on.

[FIRE UP]

Originally Posted by jimbo2013

Anyone have the steps needed, I thought the drums had to be removed to get them.

Jimbo,
Well Sir, I've done the "S-Cam" lube job and, you're right, the proper and most "complete" way of doing it, is to remove the drums. Now, this is one of those things that many will not take on 'cause of the steps involved in getting to the S-Cam. You see, for the most part, the lug nuts on most diesels are on there with some serious torque. So, those have to be broken loose. Then, getting the rig up or, at least that tire/wheel combo may be a problem for some. Now, you've got remove it, and that wheel/tire combo in some cases, hovers around, 146 lbs. plus or minus, depending on tire size.

Now, the drum itself, hovers around 75 lbs. and, can be quite cumbersome. I use a motorcycle jack to handle the job. It works slick as a whistle. It will lift that drum, just enough to relieve pressure on the studs and, slide it right off and out of the way, without me having to lift one pound. Now, you've exposed the brake shoes and the S-cam. But, here's the deal, you can just try and get one of those little soldering paste acid brushes and dab some grease on the wear sides of the s-cam or, you can do what I did.

And that was to use the slack adjusters and, back off the brake adjustment enough that, the S-cams will almost fall out. I do it that way because, I can take that S-cam out and clean it and inspect it for wear etc. Then, I lube it up, sparingly. Not too much.

I re-install it and, re-install the drums and put two lug nuts on, 'till finger tight. That keeps the drums true on the hub. Now, I adjust the slack adjusters 'till there's just a tiny bit of rubbing from the shoes to the drum. Done.

Then, I remove the lug nuts, install the wheel/tire combo and re-install all the lug nuts. I get them fairly tight and let it all back down on the ground. Then, I use my 3/4" drive clicker torque wrench and torque them all to specs, around 450 ft. lbs.

Now, I move to the other side and repeat all of it. It's really not very hard if, you've got a place to work, the tools for all of what's needed and, the willingness to take it on. Good luck.
Scott

[jimbo2013]

thanks, that looks doable, I keep a 4' breaker bar with me and 3/4 drives to break those lugs.

[Bigd9]

First I wanted to say Scott did a great job describing the cleaning and lubricating the "S" cam. I learned something new also.

And that was to use the slack adjusters and, back off the brake adjustment enough that, the S-cams will almost fall out. I do it that way because, I can take that S-cam out and clean it and inspect it for wear etc. Then, I lube it up, sparingly. Not too much.

I didn't know about the "back off the brake adjustment enough that, the S-cams will almost fall out" part. Boy that sure would have saved my a lot of time trying to clean the "S" cam.

Now for a few ideas I use to get this job done. First do not over grease the Zerk fittings on the adjuster shaft. It is possible, especially when using high pressure grease guns, to over grease and push some grease into the shoe area contaminating the shoes. (see picture)

I use a few very helpful, and not that expensive, tools to aid in getting the tire off. First is the Proto Torque Multiplier. This tool allows me to easily remove and install the lug nuts by inputting 121 pounds and getting 400 ft pounds out. Adjust those numbers to get the torque needed. (see Picture)

Next is the Tire Dolly. This is a really useful tool for me. I can lift the tire, roll it off the drum and then roll the tire out of the way. But the real beauty is installing the tire back on the drum. Roll the tire up to the drum, rotate the tire on the dolly's rollers align the holes and slide the tire right onto the lugs. (see picture)

[FIRE UP]

Originally Posted by Bigd9

First I wanted to say Scott did a great job describing the cleaning and lubricating the "S" cam. I learned something new also.

I didn't know about the "back off the brake adjustment enough that, the S-cams will almost fall out" part. Boy that sure would have saved my a lot of time trying to clean the "S" cam.

Now for a few ideas I use to get this job done. First do not over grease the Zerk fittings on the adjuster shaft. It is possible, especially when using high pressure grease guns, to over grease and push some grease into the shoe area contaminating the shoes. (see picture)

I use a few very helpful, and not that expensive, tools to aid in getting the tire off. First is the Proto Torque Multiplier. This tool allows me to easily remove and install the lug nuts by inputting 121 pounds and getting 400 ft pounds out. Adjust those numbers to get the torque needed. (see Picture)

Next is the Tire Dolly. This is a really useful tool for me. I can lift the tire, roll it off the drum and then roll the tire out of the way. But the real beauty is installing the tire back on the drum. Roll the tire up to the drum, rotate the tire on the dolly's rollers align the holes and slide the tire right onto the lugs. (see picture)

Bigd9,
Your operation is almost identical to mine with one exception. I use the "hand crank" torque multiplier. I can actually sit on my little stool, and with one arm, break all those 450 ft. lb. lug nuts loose, with one arm and, I'm no Arnold Schwartzenager. It's the torque multipliers that are sold on ebay. I paid around $165.00 for mine and, it's a 75:1 ratio unit. It's incredible how easy it is to break those loose with that tool.

As for the tire dolly, yep, right on partner! I've got one of those too and will never be without it. It makes for handling those seriously heavy tires and wheels almost a breeze. And, like you stated, it allows for stud alignment when re-installing the wheel. I got lucky on ours, I bought it at Quartzsite during the big RV event and, paid a whopping, $20.00 for it. But, the trick is, the use of the motorcycle jack for the drum.

You know, we don't do this kind of work very often but, if and when we do, having those fairly simple and somewhat less expensive tools, really makes a hard job, much, much easier and seriously safer.
Scott

[Pigman1]

All great info, but just one minor clarification. The S cams don't come out, the rollers that you see on the S cams come out and need to be cleaned and lubed. Go to NAPA and get a small can of their ultra high temp brake grease. It's purple and woun't melt off onto the brake drums and shoes on the first hard brake application.

[Fred Cooper]

That tire dolly is nice...learned something today.

If you don't have the tire dolly or the jack, you can still lube those front S cams. I only had the 3/4 inch drive wrench, breaker bar, coach leveling jacks, and jack stands. I positioned the coach so that when down on the jack stands, the wheel was within 1 inch of the ground. When you slide the tire off, it does not have far to fall. That brake drum can be easily lifted by hand (at least on my coach). I rolled the tire onto a 1 x 4 inch board and used the board for leverage to help get the tire back into position.

Fred

[KSCRUDE]

Originally Posted by Bigd9

First I wanted to say Scott did a great job describing the cleaning and lubricating the "S" cam. I learned something new also.

I didn't know about the "back off the brake adjustment enough that, the S-cams will almost fall out" part. Boy that sure would have saved my a lot of time trying to clean the "S" cam.

Now for a few ideas I use to get this job done. First do not over grease the Zerk fittings on the adjuster shaft. It is possible, especially when using high pressure grease guns, to over grease and push some grease into the shoe area contaminating the shoes. (see picture)

I use a few very helpful, and not that expensive, tools to aid in getting the tire off. First is the Proto Torque Multiplier. This tool allows me to easily remove and install the lug nuts by inputting 121 pounds and getting 400 ft pounds out. Adjust those numbers to get the torque needed. (see Picture)

Next is the Tire Dolly. This is a really useful tool for me. I can lift the tire, roll it off the drum and then roll the tire out of the way. But the real beauty is installing the tire back on the drum. Roll the tire up to the drum, rotate the tire on the dolly's rollers align the holes and slide the tire right onto the lugs. (see picture)

Ive been in the trucking business all my life. Never have I heard of anybody greasing their S cams and rollers. I would never do that. They are made to run dry. The picture in this post looks like they had wheel seal failure. That was not caused from greasing the S cam bushings. That is wheel bearing grease. Once that happens its best to throw the shoes away and replace with new. And new drums if needed and clean all the oil off of everything. It ruins brake shoes on contact. I just took delivery of a 14 Peterbilt last week, and it has air disc brakes all the way around. First one I've ever ordered this way. They are supposed to be the cats meow. Lighter, better stoping power and longer service life.

[FIRE UP]

Originally Posted by KSCRUDE

Ive been in the trucking business all my life. Never have I heard of anybody greasing their S cams and rollers. I would never do that. They are made to run dry. The picture in this post looks like they had wheel seal failure. That was not caused from greasing the S cam bushings. That is wheel bearing grease. Once that happens its best to throw the shoes away and replace with new. And new drums if needed and clean all the oil off of everything. It ruins brake shoes on contact. I just took delivery of a 14 Peterbilt last week, and it has air disc brakes all the way around. First one I've ever ordered this way. They are supposed to be the cats meow. Lighter, better stoping power and longer service life.

KSCRUDE,
While you may have never heard of it in your line of business, lubing the S-cam and rollers has been talked about and done, here on IRV2 and, RV.net on several occasions. Many folks, (guys) that drive the Freightliner chassis'd coaches, including me, have complained about the rough "noise" and "clunking" of the front end when driving and applying brakes at very low speeds. I had it happen and had no idea what it was. I looked at all kinds of possible reasons under that big beast. I couldn't find anything that looked loose, worn out, broken, anything.

I found nothing. I posted that problem on either here or, RV.net and was immediately answered with "have you lubed your S-cams"?? I said "nope" that I wasn't aware of them needing lubrication. From that point, I received several responses of folks have the same exact "clunk" and noise, at low speed, intermediate brake applications. Every one of them lubed there s-cams and, every one of them had the noise and clunk, go away, immediately.

So, I figured, what the heck, it's worth a try. So since I have all the tools and the place to do the work, off came the tires/wheels and, the drums. I already knew how to back off the brakes via the slack adjusters 'cause I adjusted brakes on fire trucks for half my life. So, as I stated earlier, I cleaned, inspected and lubed both the rollers and the s-cams, and again, as stated, a very light coat of high heat resistant grease was applied. The drums were inspected and, re-installed.

I took the big beast out for a ride and, I could not replicate that noise/clunk again, no matter how many different application conditions I tried. And yes, those pics I displayed were of the rear s-cams and, one of them did have rear axle oil on it and many other components in the area. I had to remove the axle, the hub and many other parts and do a major cleanup. But, the shoes were not contaminated at all. They were in fine shape.

I purchased a new seal (monster in size) and, made a seal installation tool and put it all back together. That was last year and it's doing fine. The pics were just to show the s-cam and it's surroundings. There's very little difference between all the working parts of the rear brake assemblies and the front.

So, yes, the s-cams have been lubed by many, at least in the diesel motor home, Freightliner chassie'd vehicles.
Scott

[dennis45]

I agree with KSCRUDE,
If you have a clunk, I suggest you have a good look at the rest of the brake components because lubing the S Cams is putting a Band Aid on an Amputation.
You can skimp on some things and get by but Brakes are not one of them. If it's worth doing, do it right.

[FIRE UP]

Originally Posted by dennis45

I agree with KSCRUDE,
If you have a clunk, I suggest you have a good look at the rest of the brake components because lubing the S Cams is putting a Band Aid on an Amputation.
You can skimp on some things and get by but Brakes are not one of them. If it's worth doing, do it right.

Well,
I'm not going to try and convince anyone here that, lubing that s-cam worked flawlessly for correcting that clunk/noise issue. I've been under cars/trucks/motor homes/boats/motorcycles for decades and have a bit of experience in maintenance. I've done more brake jobs than I care to admit and, been involved with truck/fire truck break jobs also for a few decades. And, as stated, if ANYONE did any research, they'd find that I'm by far, not the only one who's cured the "clunk" by lightly lubing the s-cams and rollers.

My brakes and all components are fine. There are no issues with any of the parts or shoes. If ANYONE chooses not to believe in this minor maintenance cure for a SPECIFIC low speed brake application problem on an air braked unit, that's fine. THERE IS NO SKIMPING on any of my maintenance. I've done more "in depth" repairs/maintenance on this coach than any other rig we've owned.
Scott

[dennis45]

Originally Posted by FIRE UP

Well,
I'm not going to try and convince anyone here that, lubing that s-cam worked flawlessly for correcting that clunk/noise issue. I've been under cars/trucks/motor homes/boats/motorcycles for decades and have a bit of experience in maintenance. I've done more brake jobs than I care to admit and, been involved with truck/fire truck break jobs also for a few decades. And, as stated, if ANYONE did any research, they'd find that I'm by far, not the only one who's cured the "clunk" by lightly lubing the s-cams and rollers.

My brakes and all components are fine. There are no issues with any of the parts or shoes. If ANYONE chooses not to believe in this minor maintenance cure for a SPECIFIC low speed brake application problem on an air braked unit, that's fine. THERE IS NO SKIMPING on any of my maintenance. I've done more "in depth" repairs/maintenance on this coach than any other rig we've owned.
Scott

Pardon me,

[Wizard]

Everyone needs to remember that most motorhomes do a lot more sitting than rolling, unlike most trucks that is just the opposite. Things tend to corrode and lock up more when just sitting.