| Author | Message | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 204 Registered: 10-2007 Posted From: 206.45.93.160  Rating: N/A |
I have been through some achives but never found a straight forward annswer. On our trip I scaled our bus and found be have over 20,000 on the drives and only about 2500 on our tags. I would like to increase the pressure in our tag air bags but how do I do this?? I'm sure there is an easy way with a valve adjustment somewhere. Thanks Grant | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1145 Registered: 12-2000 Posted From: 68.26.167.87  Rating: N/A |
Grant, There is an adjustable pressure regulator on the bulkhead near the fast idle and engine stop solenoids. On our MC-8, the factory spec is 35 PSI, but I have heard of several that have increased the pressure to 40 PSI. Jack | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 206 Registered: 10-2007 Posted From: 206.45.93.160 Rating: N/A |
excellent! Thanks Jack. I trust your travels are going good?? Haven't had a chance to check your thread on it yet. | ||
| Ralph Peters (Ralph7)
Registered Member Username: Ralph7 Post Number: 38 Registered: 3-2004 Posted From: 206.251.12.226 Rating: N/A |
Did that tag free up? | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 341 Registered: 1-2009 Posted From: 24.129.232.232  Rating: N/A |
thing about air leveling system and scales , was there any ramp or incline/decline where the roadway stopped and the scale began that you have forgotten to contend with and was the bus loaded as usual ? can makes a significant difference in your readings, especially if you don't allow enough time for pressure to equalize through those tiny line . -only weight the a old mci bus a few times, but weight thousands of loads of aggregate in many pits on many different gravel semi-truck trailer combination, some with full air suspension , some with air on one unit , spring on the next, both on the first. +also consider a faulty tag unload valve system ( if you have that option on your nine ), as that is about what the unload pressure should be, 50% of max... you wouldn't want to break frame parts with a overload or make a brake lock-up skid waiting to happen if you had not done a full inspection of the parts you can not see unless you are doing a disassembly , if you set the pressure too high & the (possibly stuck)tag unload valve system manages to free itself , or cause a sudden change in ride characteristics when murphy is on board. Consider changes to the steer weights when you get all the above "know" variables and how it changes with the tag loaded & unloaded , the next time up. P.S. the driver manual on a nine saz- not to exceed 45 kph with tag unloaded, or was that 15 mph , well , knowing is often cheaper than guessing , and much safer,I guess ??? ...There is more to it than just four bolts ... | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1673 Registered: 12-2000 Posted From: 76.69.143.97  Rating: |
Hello. 2500 lbs on the tags with 20 000 on the drives seems a little low to me. I'm suspicious as to why you aren't also reporting sliding the tag tires under moderate braking, best to be sure those brakes are working! For curiosity sake, check the pressure going to the tags as they are now. Quick and dirty, pull a convenient fitting apart and rig a tire pressure gauge to it. The tag axle structure on these vintage MCI MC7,8,9 are notorious for requiring reinforcing due to rot. Be sure your beams are in good shape before asking them to do more work. happy coaching! buswarrior | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 207 Registered: 10-2007 Posted From: 206.45.93.160 Rating: N/A |
Well I was going to keep it a secret haha, no I didn't get my tag released. One side still seized. I have had the brakes backed off somewhat but not completely on that side. I have put about 5000 miles on it, and it never released, nor I have i slid a tire, although all the grease fittings are all taking grease but I don't think the grease is making it around to the top on that side. I think we are pretrty much done with the bus for a little while, so I am going to tackle it again. I realise the ticks to scaling from my 15 years of trucking, however even with the one side being seized I think 2500 lbs or so is what I'd like to have on one side. The pressure is close from side to side according to my tire temps. The one that is froze up doesn't have quite as much weight on it because the tire runs between 5 to 10 degrees cooler. So once I get the brute washed etc. I will pull the tire, shock, block it, put some good downward force on it and get undernieth with my friend the torch and see what kind of damage I can do. Oh by the way BW the tag axle stucture looks to be in good condition, thanks for the heads up. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1146 Registered: 12-2000 Posted From: 68.26.122.6 Rating: N/A |
Grant, The last time we weighed our coach with full fuel & water, empty holding and inside fully stocked,our weights were front axle 11,800, drives 18,000 and tags 4,000. Jack | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 209 Registered: 10-2007 Posted From: 206.45.93.160 Rating: N/A |
Interesting, thanks Jack, close to ours, I don't have the weights in front of me, but my steering was around 10,800, drivers were about 20,500 and about 2500 or so on the tags. We were also full. I was expecting a little heavier, so given this info I'm gradually going to start changing my wheels over to a 11R24.5. Thanks Jack |
