| Author | Message | ||
| Glenn F Campbell (Gfcgfc1)
Registered Member Username: Gfcgfc1 Post Number: 8 Registered: 12-2008 Posted From: 63.214.229.54 Rating: N/A |
Hello ,I Have read all the archives, and I dont have 'DaBook'. I think my shutters are working OPPOSite of how they should. Please explain how they should open close and the causes of mailfunction and repair. Mine are open after parked or cold, as I drive hotter and at altitude the shut. Than when I stop they either cool off or lose some air pressue? they snap open again .This seems backward they should be open when hot ? | ||
| David Dulmage (Daved)
Registered Member Username: Daved Post Number: 246 Registered: 12-2003 Posted From: 142.46.199.30  Rating: N/A |
They should be open when the engine is hot. | ||
| John and Barb Tesser (Bigrigger)
Registered Member Username: Bigrigger Post Number: 179 Registered: 9-2007 Posted From: 96.42.7.186  Rating: N/A |
FWIW shutters have always seemed like more of a pain than they were worth. When I had them on a KW I tried to keep them working, eventually threw them away and used a winter front in cold weather if the engine didn't warm up enough. Under normal conditions I don't see what good they would be on a bus. | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 1065 Registered: 12-2000 Posted From: 71.3.157.139  Rating: N/A |
We removed the shutters on our bus. Of course, we live in Florida and try to never go north of central Florida during December through February. Jack | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 902 Registered: 11-2005 Posted From: 208.54.200.6  Rating: N/A |
Open when hot, shut when cold. Open when engine shut down. At least that is the way mine work. I like them, sure wouldn't want to go without them. Before they worked I could never get the engine to run warm enough. | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 711 Registered: 7-2006 Posted From: 75.208.41.62 Rating: |
" Under normal conditions I don't see what good they would be on a bus."..... ...really?....wonder why the engineers put them there in the first place?...  I have always understood " when you got a good thing going....why mess it up?... FWIW... But then, what do I know? (mine are welcome and ...far as I know, work just fine TTL!) RCB | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 822 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Shutters should be open when hot, closed when cool. Air pressure usually closes them, so you will find working shutters open on a bus with no auxiliary air pressure. The purpose of shutters is twofold, one is to keep the engine at operating temperature along with the thermostats. The other is power and fuel economy. A fan takes much less power to run in a partial vacuum than it does in full atmospheric pressure, so any time cooling is not needed, closed shutters save fuel. G | ||
| David Guglielmetti (Daveg)
Registered Member Username: Daveg Post Number: 56 Registered: 2-2009 Posted From: 64.163.110.102  Rating: N/A |
Now all you need is a thermostatically controlled fan and you could do away with the shutters! | ||
| Bill Holstein (Billmoocow)
Registered Member Username: Billmoocow Post Number: 17 Registered: 5-2009 Posted From: 98.232.218.68 Rating: N/A |
David, explain what you are talking about and the cost of such a project? | ||
| Glenn F Campbell (Gfcgfc1)
Registered Member Username: Gfcgfc1 Post Number: 9 Registered: 12-2008 Posted From: 63.214.229.58 Rating: N/A |
I realize the shutters should be open when engine is hot and closed to help with warming up in the cold. Mine are perhaps malfunctioning.What could cause them to close when hot? What repair will correct this OR is it simpler simplest? to remove them? I prefer system to work as designed but if it is too difficult I can chop it with out remorse....Thank you , Glenn | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 824 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
Glen, I am not exactly sure if you have a problem from your first post. Specifically, does your engine overheat every time you drive it more than about 15 minutes on a hot day? The shutters are controlled by a shutterstat which looks at the engine outlet water temperature. This will be cool until the thermostats BEGIN to open, at about 180 degrees, in MOST cases. The thermostats will not be fully open until ABOUT 190, which is the USUAL shutterstat setting. Some air gets by the shutters, providing some cooling, so around town, or on cool days on the flats, the shutters may not open. The shutterstat is not like the engine thermostats, it is on or off, depending on the outlet water temperature, a couple of feet from the engine. Follow the air line from the shutter cylinders, it will go down to the shutterstat which is mounted in the hot water pipe coming out of the engine and going to the radiators. Always air pressure in the line from the auxiliary tank, when the bus has air. Pressure in the line to the shutters when they should be CLOSED. The shutterstat is usually adjustable, we just don't know what type you have. Once again, if your bus doesn't overheat going down the road at speed, nothing is wrong with the shutters. PROPERLY WORKING SHUTTERS SAVE FUEL! G | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 90 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
Shutters were initially installed because thermostats were not that great. Then they redesigned the thermostats to be "shutterless". On my 1980 KW with 8V-92TA, it had no shutters. Only when the temp got below 30 was where I had to use a winter front cover over the grill. With the marginal cooling that buses have, I would first try disabling them and wire them open to see how it operated-then if OK, remove them. Good Luck, TomC | ||
| larry currier (Larryc)
Registered Member Username: Larryc Post Number: 215 Registered: 2-2007 Posted From: 205.188.116.203 Rating: N/A |
Since you live in AZ you probably won't miss them. It sounds like you need a new shutterstat. There is an air shutoff valve that feeds the shutterstat and with the air turned off the return springs on the shutters will hold the shutters forever open. Shutters were invented to stop engines from breaking crankshafts in cold weather. No one ever cared if the drivers froze, but engines are spendy. If you climb a mountain, the water is at max temp as you go over the top. Without shutters, the water temp drops rapidly and the crankshafts broke. With shutters, when you top the mountain and go from throttle to brake, the shutters snap shut and keep the engine from cooling to fast. If you were trained in a knowledgable trucking company you were taught to cool the engine down just before you reach the top of the mountain and a driver could add many miles of service to his equiptment by doing this. I still drive that way today although its not as big of an issue anymore. If you need coach heat in the winter, you will want shutters on your coach if it was in the original design. If you take them out, I know several people in my area where it gets cold who would like to have them. They polish out real nice. Shutterstats are available in many different temps, 170, 180 are probably the most common. Shutterstats are sold under the brand name Kysor Cadillac and the last one I bought was around $100 and that was a few years ago. If you remove them, I will give you something for them and pay the shipping. | ||
| Glenn F Campbell (Gfcgfc1)
Registered Member Username: Gfcgfc1 Post Number: 10 Registered: 12-2008 Posted From: 63.214.229.60  Rating: N/A |
Hello , Thanks fellas' Now I feel I am getting somewhere!GeorgeMC6 I will try to trace track that THANK YOU AND LarryC Thank you if I decide to remove them , I am not a parts butcher , I will let you know THANK YOU! How is the Shutterstat adjustable??? PLEASE tell me Thanks , Glenn | ||
| Glenn F Campbell (Gfcgfc1)
Registered Member Username: Gfcgfc1 Post Number: 11 Registered: 12-2008 Posted From: 63.214.229.60 Rating: N/A |
I will try to explain: My coach runs great no smoke very little oil used 1 gallon 3000 miles.The TEMP gauge on the dash reads normally above 180 below 190 ok. That is ok to me but I am a little nervous at 190ok. Now pulling the hills west bound I-10 into New Mexico temp would climb no matter if I down shifted or babied it or floored it .When I'd pull over it would cool down pretty quick on the gauge on dash and the shutters were closed when I pulled over after cool down they SNAP OPEN . I resorted to caveman tec and wedged them open with empty aluminum cans the temps stayed lower when the shutters were propped open.Is this sound like normal operation? Thank you I prefer the system work as designed but...Thanks Glenn | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1474 Registered: 10-2003 Posted From: 71.58.110.9  Rating: N/A |
I don't know if yours is the same, but on the 4104, you can shut the air off and leave them open if desired in hot weather. | ||
| larry currier (Larryc)
Registered Member Username: Larryc Post Number: 218 Registered: 2-2007 Posted From: 205.188.116.203 Rating: N/A |
Glenn, I still use them on some of my older trucks that do local work. When the shutterstat quits working properly it is usually something in the air release part of the shutterstat on the engine water manifold. So what happens is that the shutterstat reads the required temp and shuts the air off. At this point the air is supposed to vent to the atmosphere through the shutterstat, but it doesn't, so what happens is that since the air is shut off, it has to leak past a large O ring in the actuator system bolted to the shutters before they will open. Once several minutes pass the air leaks past the O ring and the shutter return springs pull them open. If that is what is happening you need the shutterstat replaced. It should shut the air off as soon as the temp reaches the number stamped on the side of the shutterstat and immediately the shutters should open. Shutterstats are not adjustable and you purchase the temp you want them to open at. Living in AZ, I would likely pick about a 170 or 175 degree, and here in Wa the 180, but I would not go hotter than 180. My old 05 ran hot with the 318 truck engine and we thought it would need more radiator for the 8V71 TA, but it did not work out that way. The TA runs plenty cool and I am wondering if it has a water pump upgrade of some kind or maybe just a better water pump. That engine will take alot of heat, as long as the coolant doesn't boil its a hard engine to hurt, if the shutters are opening/closing properly. The idea is if you get it hot, don't let it cool off real fast and keep the maximum ammount of air going through both the radiator and the engine that you can, so keep a real clean air filter in it if possible. I would not be concerned about seeing 200 degrees with the 8V71, I'd just back out and shift down before I crested the mountain and cool it some before I went over the top. Another thing I do is put heat back into the engine (throttle) in small ammounts going down the other side so the heads and crank don't have one long fast cooling cycle, thats what cracks heads, is shrinking them real fast. Oh, and thats what the shutters are designed to avoid. When I come off the highway I also have a habit of using high idle for at least 1 minute to pull some of the heat out of the engine before I shut down. A newer tight engine will spit water out if you turn them off and they are not cooled off first and one like you have is well worth a little extra care. If the shutters are snapping open after you shut down, and you still have air, you are leaving heat in the engine that should be dissipated before you kill the engine using high idle or just letting it idle for several minutes to pull the heat out. Once the shutters close, its hard to release any more heat and that is why in Az. I would chose a shutterstat that let air cross the radiator before the thermostats open when cold and also after the thermostats close when the engine is hot. 170 or 175. | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1598 Registered: 12-2000 Posted From: 76.68.133.14  Rating: N/A |
Hello Glenn. Something sure sounds strange! Have you opened the drain at the bottom of the control valve? Anything come out? You'd like to have some comparison of temperature to the shutter actions. Do you have an infrared temp gun to shoot the pipes where the shutterstat is mounted? If there is a spike in temp in the pipe where the shutterstat is mounted after shut down, that would trigger the shutters to open back up. Being from the north, I am a fan of properly operating shutters. The shutters themselves, the mechanical bits in front of the rads, are rarely the source of problem. Ensure they spring open completely, and that nothing is blocking the fins' full movement. Watch for broken or missing springs, or some obstruction to full movement. The shutters require NO lubrication, their moving parts should be clean and dry. Give them a good wash if someone tried lubing them, lube and dust creates a thickening mess that will obstruct their operation. What condition is the sensor in the pipe? Covered in greasy residue or clean? Beware! There are also the dampers on the other side of the fans, the partners to the shutters, which are NOTORIOUS for being weak at opening fully, as the return springs in the pistons age. A leaking blower gear at some point in the past will coat the fan damper hinges in the same lube and dust mix to impair their smooth movement, further impairing the system's ability to function. In a stock MC8, if one damper door hangs up by a little over 1 inch, you will get an overheat in 70 degree weather. My lazy busnut choice has been to pull the pins on the damper pistons, let them hang down, and then leave the damper doors fully open, and leave the shutters fully functional. Little air comes through from the fans with the shutters closed, so the loss in "efficiency" is small for a busnut style operation. happy coaching! buswarrior | ||
| Glenn F Campbell (Gfcgfc1)
Registered Member Username: Gfcgfc1 Post Number: 17 Registered: 12-2008 Posted From: 68.3.224.234 Rating: N/A |
Thanks a bunch! I appreciate it , This is a new ,to me , beast. I don't want to monkey around.I think the engine is fresh / tight it did spit a lil water the last time I shut it down , I thought I had been off the highway in down town long enough to 'coolit off' Thanks , Glenn | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1603 Registered: 12-2000 Posted From: 76.66.18.100 Rating: N/A |
Where is this water spitting from? Simply coming in for a landing off the highway should be sufficient to get the edge off the heat. They don't usually need any more cool down that coasting in the off ramp and toodling around the parking lot to find a spot. pressure cap on the overflow? some kind of modification by a previous owner? happy coaching! buswarrior |
