Dirty Job But Somebody has to do it!

[Jon Wehrenberg]

Dale,

This is just an observation about my brake lining, hub seal project.

I got into it because I had one of the brake shoe return springs break. When I got things apart I saw one seal was starting to leak and some oil had gotten on the shoes, and I saw one of the shoes had cracked friction material. It was because I took things fully apart that all these little things became apparent.

I should add to maintain my A1 status that once I had the wheel with the broken return spring apart (that was the only problem there) I took the other one apart just to do a detailed inspection and found the remaining problems.

It was at that point that I looked at all the other linings and just decided to do the entire bus, and to replace the leaky seal.

My coach at the time was in the 175 to 185,000 mile range. While none of the shoes was worn down to the point where the friction material absolutely had to be replaced, several had cracks radiating from the screws holding them in place. But, and this was unknown to me, I had two seals replaced early on by Prevost before I started doing my own work, and I found that the oil from the seals seemed to have glazed a couple of the linings. When I replaced the brake lining friction material my coach stopped like it never had before. I never knew how bad my brakes were.

Our brakes are not that good relative to the other vehicles on the road, and I now know anything I can do to improve them is a big plus.

[dalej]

Peter, I like the way you think, it make very good sence to me.

Jon, I will be cleaning up all the parts soon so I can take photos if somthing looks questionable. I wll be asking more questions I'm sure.

I sure don't want to still be working on the bus for at least a week from leaving for Kerrville. Keep in mind if you don't see me at the POGIII, one of the hubs probably fell off along the way

[Joe Cannarozzi]

Peter

I think you are dead on with your comments and observations regarding the Dryer.

The contaminating oil is deffinatly a common occurance.

I would also like to add that concidering its location on the bus compared to where they are mounted on semis it is shielded better in extreem cold conditions and probably would last longer without failure in those conditions.

Failures at the heating element or power going to it are also reletivly common as well.

Good comments about conciderations of adjusted service intervals with our application.

[JIM CHALOUPKA]

Peter

I think you are dead on with your comments and observations regarding the Dryer.

The contaminating oil is deffinatly a common occurance.

I would also like to add that concidering its location on the bus compared to where they are mounted on semis it is shielded better in extreem cold conditions and probably would last longer without failure in those conditions.

Failures at the heating element or power going to it are also reletivly common as well.

Good comments about conciderations of adjusted service intervals with our application.

Peter, how can you tell if the desiccant is contaminated?

Joe, how do you know that the heating element is functioning ?

[Gary & Peggy Stevens]

Keep in mind if you don't see me at the POGIII, one of the hubs probably fell off along the way

Dale; Don't even JOKE about something like that happening!!!!!

Gary S

[dalej]

When we built our house in 87/88 I did a lot of the work myself and I always have this feeling that I might have forgot somthing. So when the wind blows (which it does a lot in Nebraska) I look for somthing like the roof to fly off.

I have been cleaning the hubs, drums and everthing else while I wait for the new seals to arrive.

I'm pretty sure the seals have never been touched since I have been having a time seperating the drums from the hubs. One down and three to go. Probably start putting things back together tomorrow or Friday.

If I thought anyone out there would do this I would take photos and do a show and tell via the internet.

[dalej]

If I were you guys I would invest in floor-dri, the way I'm using it it's bound to go up. I can't believe how much 90 weight gear oil soaks up this stuff.

[Jon Wehrenberg]

Dale,

Go to the front page of the POG site. I wrote a blurb about replacing the hub seals. I would appreciate if you could refine it because my old bus was long gone when I wrote it from memory.

Make all the corrections you need to, add better or more pictures and see if Jim can post the revised updated document.

Jon

[Gary & Peggy Stevens]

If I were you guys I would invest in floor-dri, the way I'm using it it's bound to go up. I can't believe how much 90 weight gear oil soaks up this stuff.

Dale: You mean how much Floor-Dri soaks up the 90 weight gear oil, RIGHT?

Its probably just dislexia, or is it aixelsid. I think it comes with age.



I used to think I was wrong, but then I found out I was mistaken.

Gary S

[Petervs]

Hi Dryer fans.

The electric heater is only there to keep the unit from freezing in cold weather, heat trace if you will.

The desiccant is clean and white when new, and if any oil or dirt gets in there it begins to discolor a bit. When you change the desiccant cartridge you may be able to see the diffrence if you had been passing any oil.

The desiccant is a surface area type of thing, a pound of desiccant has like an acre of surface area ( it is porous like a sponge, only hard as a rock) and there are "sites" where the water molecules grab on. If they are covered in oil they are no longer usable by the water molecule. Eventually you replace the desiccant to keep it working.

In the industrial world, there is a special coalescing filter installed in front of the dryer to catch liquid water and any oil, so only oil vapor and water vapor gets to the desiccant. In that application, we recommended 5 year desiccant changes, but it was not needed for 10 years, and that is with the system running 24/7.

In our case, the air is hot from compression so would not have any liquid water in it at that point, only water vapor. But it is always 100% saturated with water, like 100% humidity. Think of outside air on even a dry day at 15% humidity getting sucked into the air compressor, then compressing 8 times ambient pressure to 110 psi, , the same amount of water is still in there! So if you run it down a long pipe or store it in a tank for a while, it cools back down and essentially rains inside the pipe or tank. That is why liquid water builds up if you do not have a dryer to remove it, or operate the drain ports regularly. Leave it in there on a freezing day and the frozen water blocks the air from doing it's job, like operating brakes.