Freightliner S-cams?

[rvrat]

Hello all, I think the S cams on the front brakes of our 02 Journey with the Freightliner chassis are rusted and sticky. I think from driving in the rain and snow (not on purpose) the right S cam may be rusted solid. My question is, can I free the cams myself without removing the wheels and brake drums? What is the method if I can do it myself?
Thanks in advance for the help, Bob

[Martind4]

When I did my S-cam rollers, I had to remove the wheels, brake drums and the brake pads. Duane from Freightliner Help Line was most helpful in making sure everything went back together properly and the self adjusters were working. Make sure you have adequate sized jack stands before you start. When I finally got to the rollers I used a wire brush mounted on a bench grinder to clean them up. A wire brush mounted in an air drill worked well on the S-cams themselves. The whole project took me a couple of days (one for each front wheel), but would go a lot faster the second time around. Duane suggested I have the factory or another FL service center do the rear wheels because of the spring loaded parking brake and the weight of the dually brake drums. I took his advice.

Definitely a do-it -yourself project if you have the tools and desire. FL said that once the rollers are lubricated and free, it probably won't need to be done again in my lifetime.

2000 Itasca Horizon, Cat 300, FL XC chassis, 102K miles

[J Walker]

I read about the S-Cam lubrication a while back and got a download on the Meritor S cam which shows how to disassemble it. I no longer have the link to share. I learned that lubing the slack adjusters also lubes the S-Cam so hopefully it will never need to be disassembled. What I don't know is how to tell if you need to free up the S-cam.

[Pigman]

You'd best be careful trying to lube the cams through the slack adjusters. To begin with, there is no way to tell how much grease you're dropping inside the brake. A bit of heat and it's all over the shoes, and that can get expensive real fast. Also the grease will not get past the cam to the outer areas where the roller rests on the shoes.

At the Camp Freightliner classes, Mike recommended no more than three pumps into the tube zirk between the slack adjuster and the wheel brake. This assumes you lube the chassis at the 6000 mile interval recommended in the maintenance schedule.

John

[J Walker]

Quote:

Originally Posted by Pigman You'd best be careful trying to lube the cams through the slack adjusters. To begin with, there is no way to tell how much grease you're dropping inside the brake. A bit of heat and it's all over the shoes, and that can get expensive real fast. Also the grease will not get past the cam to the outer areas where the roller rests on the shoes. At the Camp Freightliner classes, Mike recommended no more than three pumps into the tube zirk between the slack adjuster and the wheel brake. This assumes you lube the chassis at the 6000 mile interval recommended in the maintenance schedule. John

I didn't attend Camp Freightliner since either I didn't know about it or it had not started in 2000 when I got my MH. Anyway, I have always lubed the same way which is to pump until grease comes out of the slack adjusters. That is a whole lot more than three squirts. I lube at about the 6000 mile point or once a year. I hope this procedure works and I haven't had any problems in nine years.

[Pigman]

Jim, I was talking about the zirk on the outer end of the tube that runs from the slack adjuster to the brake. The slack adjuster is greased until grease appears at the slack adjuster spring loaded dog. Then 3 shots into the tube at the brake end. This is for rear brakes only. Fronts are all different depending on suspension, disk or drum, and other factors.

Regardless, you can't lube the S Cam rollers without pulling the drums. Meritor recommends every 6000 miles/ 6 months, and that's what Freightliner restates in their maintenance schedules. But you can't do these without pulling the duals and drum, and most techs won't do it, regardless of what they say they did. I've had issues with Oasis shops about this.

I do mine once a year using a high temp brush on brake lube I got from NAPA. I just did mine this morning after an 11,000 mile Alaska jaunt, and found them fine. I may go to M-3 cycles, 24.000/24 mo, as I could still see evidence of the purple grease on the rollers and rubbing surfaces. This is also a great time to check shoes, springs and the rest of the internal brake assembly.

John

[J Walker]

Pigman, Thanks. I will look at my rear lube points when I do my fall lube soon. I am lubing all of the zerks I have. I have never pulled the wheels and lubed the S-cams and don't plan to. I may be sorry. What an awful place to lube on a regular basis. It is hard or impossible to do yourself and I am sure very expensive to have a shop do it.

[FleetMan]

FWIW. In the fleet maintenance program I was involved in, we cleaned and lubed the S Cam Rollers only when we pulled the drums for brake or front wheel bearing work. Intervals could run well over 100,000 miles for OTR rigs and I can't remember ever seeing a frozen or bad roller. Having seen some of the litigation and litigation considerations facing the industry, many of the recommended maintenance items are purely CYA measures on the part of the manufacturer, they are not based on real world maintenance experience.

[Gary RVRoamer]

Just one precaution: OTR trucks seldom sit long enough to ever rust up a brake caliper or anything else. Constant use avoids that problem, at least. RVs, on the other hand, tend to sit around a lot and things seize up.

[J Walker]

Quote:

Originally Posted by FleetMan Having seen some of the litigation and litigation considerations facing the industry, many of the recommended maintenance items are purely CYA measures on the part of the manufacturer, they are not based on real world maintenance experience.

Interesting. Some of the service intervals for MHs seem unrealistic to me, though I say that with caution. It seems that many of our components are derived from trucks where miles are nearly always the governing factor. For MHs miles are usually never the deciding factor but time is. How the time interval is determined is sometimes a mystery to me. I usually stay close to the specified time interval but sometimes I stretch it some, and even they I probably could go further.

[wagonmaster2]

I have pulled front drums on many chassis that required the bearing be packed with grease but haven't yet on my Freightliner chassis with oil bath bearings, and solid front axle.
Can someone describe the procedure for pulling these drums off? When I've changed the oil bath fluid I can't remember seeing a nut and lock key (or however the nut is locked in place). Is there any definite procedure for adjusting the bearing nut, which on the packed bearing hubs I always set the bearing nut up firm then backed off to the the first cotter pin slot. And I assume like the other drums, the wheel must be removed first.

Appreciate any help here.

Wagonmaster2

[Martind4]

Our 2000 Freightliner XC chassis with the solid front axle doesn't require anything to be disturbed on the oil bath bearings in order to remove the brake drum. All I had to do was remove the wheel lugnuts (& covers), wheel and pull on the brake drum. Sometimes there may be a tinnerman nut on one of the studs that also needs to be removed. The axle bearings and brake drums are totally separate pieces.

FWIW, the FL help desk (Duane) told me that unless the bearing is leaking, don't mess with it. Check the level and don't worry about draining or changing the oil in the oil bath bearing.

[indiana journey]

I've done the front wheels-remove wheels, remove brake drums, check brake shoes, lube s-cams. My question is; how do you get the rear brake drums off? I've removed the rear duals and have the emergency brake off and the brake shoes won't budge. Did I miss something? How do I get them off?
Any and all help is appreciated.
Thanks, Indiana Journey

[smlranger]

Quote:

Originally Posted by indiana journey I've done the front wheels-remove wheels, remove brake drums, check brake shoes, lube s-cams. My question is; how do you get the rear brake drums off? I've removed the rear duals and have the emergency brake off and the brake shoes won't budge. Did I miss something? How do I get them off? Any and all help is appreciated. Thanks, Indiana Journey

OK. I'll take a stab at an educated guess....if your air has leaked down to a pressure below 60 psi, the spring which activates the parking brake will apply the brake, even if you have pushed the button in. You would have to have enough air pressure to compress the spring to release the brake.