| Author |
Message |
Norm Edlebeck (199.3.9.7)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 06, 2001 - 12:01 am: | |
Need some advice on best course of action to take on 1970 MC-7 that is rusted and leaking air above the drive axle air bag and the air chamber above it. One possible solution suggested putting in 2 air tanks in the rear bay and somehow inserting a steel plate between the present air chamber and air bags, thus eliminating the present air chambers which would be replaced by the 2 new air tanks in the bay. Will this work??? Anyone else have the same situation - maybe different solution??? It is not to critical stage, but needs to be done in near future. HELP !!! |
Frank Walka (Ivirfrank) (64.12.104.181)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 06, 2001 - 3:14 pm: | |
Hello Norm:
Not to imply that MCI used outdated technology :-), but when a fleet that I worked for finnally got rid of all the 4104's with the bellow bolts, all use guys in the shop rejoiced. Then they went and bought two MC-7's, we were in tears. But the fix on the old GM's was to use a plate between the bellow and the beam, drilled for the bellow bolts and having an air line to go to the leveling valve. Obviously, you'd need to do this in pairs at each wheel position. We even did it one side at a time as they would go bad and did not see a noticable difference in the ride by eliminating the volume of air in the air beam. We used to buy the plates already made, but it would not be hard to fabricate. There was always available a supply of bellow bolts in different lenghts and head styles to accomodate these changes. I kind of think Firestone makes a double-bubble bellow with a solid upper and lower plate that attaches with two studs at the top and two studs at the bottom which you could also get in there.
Remember that ride quality is dependent on air pressure in the bellows, not volume. So to get the same ride, use the same diameter bellow, for a harder ride, smaller, a softer ride, larger.(This is like spring rate on a mechanical spring)
Frank |
Jim Ashworth (Jimnh) (172.166.251.2)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, May 06, 2001 - 7:30 pm: | |
As to the extra tanks to replace the volume in the air beams, Prevost has just recently been doing this to improve their ride. They use a rolling lobe airbag that has the top plate with the air fitting. You will have to cut away the tube that supports the present air bag and leave room to access the mounting bolts and air line for the new bags. If you go this route, oversize the air line from the bag to the tank to ensure adequate flow. If the bus hasn't been converted yet, remove the floor and rebuild the existing air beam. This will be the best solution and if properly rustproofed, will probably outlast the bus. To just plate over the existing bags or using a rolling lobe bag kit will make the thing ride like a skateboard. Not noticable up front from the driver's seat, but sit in the back and the bumps will beat the crap out of the bus. I have been that route and found it worth it to tear up the floor to fix it the way MCI designed. Having owned both MCI and Prevost, in my opinion, the 8's & 9's are still the best riding busses on the road because of the extra volume of air in the beams.
Jim |
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