| Author | Message | ||
| Joe & Brandee (Bioventure)
Registered Member Username: Bioventure Post Number: 4 Registered: 11-2010 Posted From: 68.188.235.159  Rating: N/A |
So we awakened our bus from a three year slumber from which the previous owner put a total of 100 miles on. Some documentation and service records were still on the bus when we bought her. Being retired from service I think around 1990. It had and engine overhaul and new clutch in 1989. The installed hubmeter shows 78K miles. After that was used as a church bus and prob not very well maintained. We had (what I suspect) is a rear brake valve fail on her 180 mile trip home. I can hear a leak near the rear and park brake keep setting itself. My real concern is getting the engine tuned best I can. She burned about 1\2 gal oil on the trip home (some of that leaked out, she leaves quite a puddle) Where can I get procedures on setting the inj. timing and other regular maint. adjustments? | ||
| les marston (Les_marston)
Registered Member Username: Les_marston Post Number: 233 Registered: 1-2010 Posted From: 68.151.225.213  Rating: N/A |
It is common for 2 stroke detroits to leak. Some people think if they don't leak they aren't running properly. Tuning the engine wont do much for leaking, that just takes time and effort to find and fix. How well does it start? How much does it smoke? how is the power? These sorts of things are indicators of tune up time, not oil leaks. If this engine has sat for a long time or has been idled a lot a good long run was the best thing you could do for it. My old 8V71 would blow out the first 1/2 gallon of oil if I filled it to the mark on the dip stick then settle down to very low loss | ||
| Joe & Brandee (Bioventure)
Registered Member Username: Bioventure Post Number: 5 Registered: 11-2010 Posted From: 68.188.235.159 Rating: N/A |
8v71 - has 2 new 8D batteries and starts great even @ 30 degrees without being plugged in. Before her trip home it smoked a little all the time. I've heard idling is not good for them so I try not to do so for long and when I start her periodically to keep the batteries up i run it on fast idle. Id does however smoke pretty good on acceleration. Hard to tell if its fuel or oil though. I run an auto repair shop so I have a good mechanical aptitude but very little experience with these monster diesels. | ||
| Joe & Brandee (Bioventure)
Registered Member Username: Bioventure Post Number: 6 Registered: 11-2010 Posted From: 68.188.235.159 Rating: N/A |
oh, and it does seem to have good power, although i really have nothing to compare it to? | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 1001 Registered: 8-2006 Posted From: 74.33.43.204 Rating: N/A |
Very first thing is check and see what oil is in it the 15/40 will leak and smoke on a 71 series go with the single grade 40 w good luck (Message edited by luvrbus on January 10, 2011) | ||
| Gary Seay (Gdude)
Registered Member Username: Gdude Post Number: 31 Registered: 6-2010 Posted From: 216.67.52.2  Rating: N/A |
Joe One thing to check on for excessive smoke is the oil. Some guys make the mistake and run 15w40 and the 2 stroke should run ( Delo 100) 40wt Just a thought Gary | ||
| Gary Seay (Gdude)
Registered Member Username: Gdude Post Number: 32 Registered: 6-2010 Posted From: 216.67.52.2 Rating: N/A |
Sorry Must have posted at the same time | ||
| Joe & Brandee (Bioventure)
Registered Member Username: Bioventure Post Number: 7 Registered: 11-2010 Posted From: 68.188.235.159 Rating: N/A |
Come to think of it I did read that somewhere else too. I think the previous owner was running 15w/40 rotella which is a great oil, but not right for this application. I will be changing out all her fluids once spring hits. 20 degrees is a bit cold to be rolling around on my back in the snow. :-) What about rocker adjustments, and ive heard talk about setting injector height or something like that. I'm not paying for labor so anything I can do to get her TIP-TOP. Gonna have to learn anyway, but I would prefer not to learn on the side of the highway :-) | ||
| Gary Seay (Gdude)
Registered Member Username: Gdude Post Number: 33 Registered: 6-2010 Posted From: 216.67.52.2 Rating: N/A |
Joe come on I read someware you are only in your early 30's Rolling around in the snow and cold should be nothing. Lol I live here in Alaska and i'm kinda hibernating for a while. Gary | ||
| Cory hart (Chart1)
Registered Member Username: Chart1 Post Number: 35 Registered: 1-2010 Posted From: 66.249.37.60  Rating: N/A |
There is a lot to know on tuning these beasts. First of get a copy of the detroit 71 series manual and there is a whole section on tune ups with a list of the special tools with part numbers that you will need to do the job. | ||
| Cable (Fe2_o3)
Registered Member Username: Fe2_o3 Post Number: 61 Registered: 10-2004 Posted From: 74.110.84.128  Rating: N/A |
You probably already know this, but, I'm going to say it again.. Never get under the bus until you block it up.. A failure anywhere in the air suspension will crush you...Cable | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1762 Registered: 12-2000 Posted From: 71.195.124.20  Rating: N/A |
Joe - FYI, Greyhound used to "run the racks" on their two-strokes every 100,000 miles. As Cory mentioned, the proper procedure is spelled out in the DD 71-Series manual, but it still requires a little "touch" to really get the rack set correctly. Ask Don Fairchild. One thing you're going to have to wrap your brain around is the fact that diesels cool when they're idling, just the opposite of a gas engine. Thus, even running the engine on fast idle will not put enough heat or load into the beast to really bring it up to operating temperature - especially if it's in a Michigan winter. Add in the wrong oil, and you're creating a great mosquito fogger. The best thing you could do for your Buffalo right now is to pull the batteries, putting them on a smart charger to keep them up. Just let the old girl sit as is until the weather gets warmer. Then re-install the batteries, check the oil level (the full mark on the dipstick should be 1" below the oil pan/block interface) and take her out for a drive. Not around the block, but 50 - 100 miles. Drive her like you just slammed the door on your hand - don't baby it. Come back, grab your seven gallons of straight 40wt CF-2 oil plus a filter and drain out the multi-weight while the block's still warm. Then take it out and drive it another 50 miles or so. Only by running it under load will you get the smoke to clear up, if the engine is in good condition. (Sounds like it is, since you said it starts easily at 30 degrees w/o being plugged in.) The more you run it, the better. When cold, white smoke is unburned fuel. Should go away as the engine comes up to normal operating temperature. Blue smoke, regardless of engine temperature, is burned oil. Black smoke from a warm engine is unburned fuel, either from a plugged air filter, or too much throttle under load (like pulling a grade before downshifting). Fastest way to overheat the engine, too! FWIW & HTH. . .  | ||
| RJ Long (Rjlong)
Registered Member Username: Rjlong Post Number: 1763 Registered: 12-2000 Posted From: 71.195.124.20 Rating: N/A |
Joe - I just re-read your original post. Your FIRST concern should be fixing that air leak, not worrying about "running the rack." If it's leaking enough to be automatically setting the parking brake, you've got a major leak that needs to be fixed BEFORE you ever take the coach back out on the highway. (I wouldn't even suggest driving it "as is" a mile to your shop - unless it's parked out back!) Seriously - this is a MUCH higher priority than the engine's state of tune. Take a look at the rear brake cans. OEM on the Buffaloes were DD3 brakes, which have three air lines running to each can. If your bus only has two air lines on the brake cans, then a PO has changed out the DD3s for spring brakes. DD3s can be rebuilt on the workbench. Spring brakes, OTOH, should simply be replaced - without the correct equipment, they can be deadly when taken apart by someone unfamiliar with their innards (compressed spring has enough force to blow a hole in a concrete block wall!) A blown rubber diaphragm in either, but especially the DD3s, can deceptively sound like it's coming from somewhere else. Fix the air leaks, THEN run the rack on the engine. FWIW & HTH. . . PS: If you have some trouble shifting your coach, take a look in the "Articles of Interest" section of BNO's BBS for a helpful commentary. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1411 Registered: 10-2006 Posted From: 66.82.162.20  Rating: N/A |
First thing is , GET DA BOOK! the maint and parts and drivers books for your specific coach. Then do all the maint , the 1500 mile required ,all the way to the end.Start with adjusting the chassis brakes , and then the emergency . A pair of lumber 8x8 3ft long will help get under. Most maint is lubrication , is required , and will help your coach . Then run it a couple of hundred miles , after you have CFII 40 wt oil in it. You will be amazed at how much grease it takes to blow out all the old grease , so get a bunch of your favorite, DA book specifys the type , you choose the brand.. Do the front wheel bearings , get new seals and I prefer synthetic grease , use your favorite. ON a nice day spray the engine with a half dozen cans of Gunk , rinse anf go for a 5 mile ride. Park in a clean spot and see what you can to find some of the leaks. Running the rack can be done , just by purchasing the "pin" and following Da Book, but it is FAR BETTER to observe an experienced person do it first.New valve cover gaskets a plus. Have fun, FF | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1972 Registered: 12-2000 Posted From: 174.89.176.154  Rating: N/A |
Yes, please, as RJ has pointed out, get your air system leaks fixed. Air in your coach is equivalent to hydraulic brake fluid in an auto, no juice, no stop. No air, no stop. Stopping is job one. Then worry about going. If that big diesel runs, the state of tune can patiently wait until the rest of the ignored maintenance is caught up. Lots of systems to check and confirm functional, lots of lubrication, lots of cleaning, lots of adjusting. You can frustrate yourself with many more things before delving into the realm of Detroit rack running... Welcome to the insanity! happy coaching! buswarrior | ||
| ED Hackenbruch (Shadowman)
Registered Member Username: Shadowman Post Number: 345 Registered: 11-2003 Posted From: 75.211.185.73 Rating: N/A |
I second RJ, fix the air leaks first. Change the air/fuel/oil filters and oil, then think about a tune up. It might not even be needed. | ||
| Joe & Brandee (Bioventure)
Registered Member Username: Bioventure Post Number: 8 Registered: 11-2010 Posted From: 69.41.12.140 Rating: N/A |
Thanks for all the info guys!! Cable, safety is #1 on these widow makers!! But u can't stress that enough i know! RJ, a friend once told me I need to drive her like im mad at it,lol and i fully agree. I have no problems with that accelerator pedal :-) I agree that the air leak is priority #1 here (especially after the tow bill I had to pay to get her the rest of the way home). I am just trying to get a game plan together for when the weather permits me to start opening that can of worms :-) When we brought her home about 10 miles from our destination the rear brakes started dragging and got overheated pretty bad. Now the park brake will reset itself about 1 min after being released. I have read on other forums that the valve in the rear that controls the brake chambers has a tendency to get plugged up with crud when not in use for long periods of time like she has? | ||
| ED Hackenbruch (Shadowman)
Registered Member Username: Shadowman Post Number: 346 Registered: 11-2003 Posted From: 75.211.142.231 Rating: N/A |
Check your air tanks and see what comes out of them. Could be a line is full of crud where it comes out of the tank. | ||
| tony denny (Papatony)
Registered Member Username: Papatony Post Number: 22 Registered: 10-2010 Posted From: 74.206.82.239 Rating: N/A |
Joe: If you want to run the rack find an expersied machanic to do it , watch him close then you can do it your self. belive me it is nothing like a gas engine or most other engines you have worked on. | ||
| Joe & Brandee (Bioventure)
Registered Member Username: Bioventure Post Number: 9 Registered: 11-2010 Posted From: 68.188.235.159 Rating: N/A |
I am currently doing some work for one of our local fleet shops, so I will probably be calling in a favor when the time comes ;-) Ed, I tried to purge a couple of the tanks, the one under the driver will not purge the valve is so plugged, the one above the battery tray I installed a ball valve to purge the bottom of the tank and was amazed when I seen what came out. I know that tank does feed the brakes but not sure if it is only frt, or rear or both? But the crud that came out is a good sign of what caused the brakes to fail for sure!! |