| Author | Message | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 34 Registered: 12-2011 Posted From: 99.100.88.196  Rating: N/A |
Well I am making progress in getting heat in my bus. 61 TDH 4516 Buying a bus from southern California they only said the air didn't work... They never used the heat. After few days driving home with the temp in the teens it didn't take long for me to want to get that fixed. Going through the learning process of how the bus heat system works I could not have been more unlucky in the detection of the problem, or as it turns multiple problems... And every step of the way when I find a problem I'm sure it's the answer but they only need to another problem then to another and it's actually getting kind of amusing. First problem the easy solution open the circulation valve and oh yeah the easy fix right... Not!! But it was one part. I feel slight warmth in the dash so I investigate and the blower motor has a broken brush spring so I got that fixed and then I had a tiny bit of heat on my toes. Then I investigate and find out that the coolant heating system pump is not working. I take the pump apart because it's locked up and get everything un corroded and spinning. Put it back together and the motor was not working. I take the motor in for repair and they told me it was burned up. So I buy a new motor put it all back together and then I have slightly more heat. Then I investigate and the back of the defroster heater/radiator was so plugged up with gunk, tar, dirt, dust, and every king of trash. After cleaning yeah!!! I have a hot defroster and driver heat. It actually heats the whole bus a touch. Main heat I knew one of the two blowers was not working I noticed that early on. The power was disconnected to the motor I checked the wire and voltage and everything checked out so I hooked it back up but no go on the motor. I still figured that one blower would be enough to get heat I was only getting slightly warm from the main cabin heat. I pulled the blower today and am taking it in for repair tomorrow hopefully it will be a cheap repair. Since the front defroster was so plugged up and no airflow was getting through I pulled the air filters. Let me first add that I opened the hatch before and looked at the back side of them and thought they look clean enough.... Haha my bad.. I dropped them today and they were so full of crap I actually took them in and weighed them on my UPS shipping scale... OMG 16.4 lbs of air filters. And I bet 3-4 lbs fell off when I pulled them out. Hopefully when I get it all put back together I will finally have really good heat. I'm sure there will be more issues but at least I'm making progress. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 601 Registered: 3-2006 Posted From: 216.198.139.38  Rating: N/A |
Scott I remember you said you had the maintenance manuals. Keep at it. You will get it to work yet. There is a modulating valve near the pump you had fixed which is controlled by the grad-u-stat. There is also a screen in the coolant hose that comes from the thermostat housing to the heater line. It can get plugged up as well. The screen is by the bulk head when you remove the hose. Bill | ||
| Brandon M (Brandon314159)
Registered Member Username: Brandon314159 Post Number: 65 Registered: 3-2011 Posted From: 71.193.166.23  Rating: N/A |
On my 55 TDH 4512 someone has removed the drivers heater, leaving on the rheostat in the dash that used to control the fan. Sad. The main coach heat didn't work for quite some time (had flow, could feel hot pipes near my shoulder going up the wall), then one day decided to kick on and blew rats nests and stuff out all the vents over the windows. *YUCK* Turns out the solenoid is bad, and needs replacing. I vacuumed all the rats nests off the heater core (about 24x24") so that helped too. Doesn't smell nice, but makes a load of heat! | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 35 Registered: 12-2011 Posted From: 99.100.88.196 Rating: N/A |
We replaced all of the coolant hoses in the engine compartment and there was no screen where it was supposed to be. Actually the hunt for the screen is what made the hoses need to be replaced. They were dry rotted and removing them was too much for them and they were to brittle. It avoided future problems. The modulation valve is working and coolant is going through, the heater cores are warm. I've cranked the temp setting up on the gradustat and actually tested it with air pressure and it's opening and closing the valve. It might be the one part that's actually working. I'm hoping that the severly clogged filters were not allowing airflow to get through the heater cores. I'm also going to verify that there is coolant at the top of the heater cores and not air since I have them exposed. I have read that they might need to be burped. I'm also going to point my thermometer at the lines and take some temp readings but circulation seems to be working but I'm going to verify it. Question about the A/C unit. Can they be repaired and who has that skill if so? All the parts seem to be there and look like good shape. The compressor yoke is disconnected. I'm assuming it needs to be rebuilt but who knows. I was told it was drained of coolant and disconnected when the bus was taken out of service. This one I will leave to a professional. | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 36 Registered: 12-2011 Posted From: 99.100.88.196 Rating: |
Also the manuals mention a "clogged air intake screen" as a possibility of under heating issues, separate from the filter screens that was on another line of under cooling reasons, but shows no photos. I just read that last night so I'm going to go back to the diagram and look for them. If there is one, I don't remember seeing it anywhere mentioned but I was not exactly paying attention for it either. Oh and only three dead mummified Mice fell out of the heater box cover when I dropped it. There were four in around the modulation valve along with a chunk of some probably 1960's long since banned rodent killer. I'm guessing it saved my wiring from getting eaten. I have renamed the rear right side ducting the "valley of the kings" in honor of the mummified mice uncovered in my archological digs over there.  I did find a 1968 bus schedule in the one heat ducts that was kind of cool. I could not resist the urge to outline the mouse bodies with white chalk but I only had white-out and it sort of worked but all the dirt clogged up the brush and when I cleaned the white out didn't stick to the floor... It was going to be a photo op but it didn't work out right. Boredom + creativity = strange crap getting done. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1652 Registered: 10-2006 Posted From: 67.238.59.158  Rating: N/A |
Std Coach engine driven air cond can be repaired , tho its very uncommon.AS its very expensive. Even brand new the huge system would loose 3-5 lbs of freon per week! A cheap carbunkle roof top unit and a good inverter is one solution, tho some simply use the noisemaker on the road.We avoid extreme summer , so a 4104 set of drivers and door opening windows is fine. I think most folks do away with the gradustat , as it is needed for air cond. Simply turning on the circ pump works for most folks. Our solution (4106) was to toss all the air cond stuff and the huge heater core, and blowers. A 40,000 btu marine heat unit was paralleled with the defroster . It grabs outside air from the duct work that used to feed the HVAC system. I control the defroster and drivers heat , the bride gets 3 fan speeds and total temperature control with a throttle cable to the heater valve. The 3/4 valve set for a cable was only $13.00 last time I bought them from Mohawk. On full blast the system heats the front half of the coach into the high teens , the rear gets heated by the propane furnace when we stop. FF | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 2229 Registered: 12-2000 Posted From: 174.91.142.236  Rating: N/A |
Air intake screen may refer to the outside of the coach, On both sides in the area of the HVAC cavity. Where the ducting sources fresh outside air. A stray piece of newspaper floating in the air can get pulled up against it, as well as leaves getting caught up in it. Or worse. For bus conversion use, consideration for control or elimination of the vast intake of outside air that needs $$$ to heat/cool when you do not need that mush fresh for two people. happy coaching! buswarrior | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 37 Registered: 12-2011 Posted From: 99.100.88.196 Rating: N/A |
I thought I was just buying a bus.... The "general contractor-superintendent-engineer-mechanic" job titles were never mentioned.... But I'm addicted and in love so what do you do. Let's see it's kinda like having a tree house that you can take places with you... FUN is how BUS should be spelled | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 602 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Scott If you can enlarge my picture you will see the front licence plate says FUN SUN. Close to what you are talking about. Like BW says the air intake screens are on the exterior of the side of the bus to allow fresh air into the heating system. Very few people rebuild the A/C system due to cost. Bill | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 38 Registered: 12-2011 Posted From: 99.100.88.196 Rating: N/A |
how many btu's unit will it require to cool a 35' bus on a hot summer day? Is it best to use 1 unit or 2... roof top rv type I'm assuming? They run off an inverter or generator? Clueless never looked into them. | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 741 Registered: 2-2001 Posted From: 184.0.13.120  Rating: N/A |
In our 4104 with leaky original windows, 1 x 15K in the front and 1 x 15K in the bedroom does not get the job done in Southeastern U.S. Two x 15K in the front would "git 'er done" tho. We run the gen while not plugged in. Can't hear it while moving. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 603 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Scott I run a 13.5kw in the front and a 13.5 in the rear and have never had a problem. I found that the front unit must be as close as possible to the front for travelling to feel the benifit in hot climates. I also have a fan on the drivers and passengers side at the top of the windshield to blow the cool air on you. That makes a big difference as well. A lot depends on how cool you want it to be. A lot of times you wonder if the A/C is working till you step outside then you know it sure was. If your A/C runs enough to remove the moisture you don't have to be at 65 degrees to feel good. If you have removed the moisture 80 degrees is comfortable. Another thing is how much insulation you have in the walls and roof. Bill | ||
| Bruce Henderson (Oonrahnjay)
Registered Member Username: Oonrahnjay Post Number: 720 Registered: 8-2004 Posted From: 70.60.102.99  Rating: N/A |
Bill has some excellent points. Those big windshields are bad for what we used to call "solar loading" on AC projects. It only takes a little direct sunlight to really warm things up -- and a bus gets a lot more than "a little"! As Bill said, getting the moisture out of the air is a must (watch air infiltration, it can drive you crazy if you have a lot of moist air blowing into the bus -- you'll never get it dry) and circulating dry and reasonably cooled air can make a big difference. In the summer, you want a lot of air movement and little leakage -- if you have outside air leakage, you don't get "recirculate"; you are blowing cool air out and damp air in! | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1430 Registered: 11-2005 Posted From: 75.121.203.117  Rating: N/A |
Pay close attention to what Bill said about getting the rooftop AC as close to the driver as possible, even the second bay is too far back!! Install the rear AC more toward the front also, there is no need to have it in the bedroom. Actually it is a waste there because it gets too cold and is too noisy. Once the sun is down one will freeze you out and you don't want it near the bed. We use only the front one at night. We use the rear one only during sunlight hours after we stop for the night. We have doors to block off the rear from the front so we only used one AC moving, two would have been better but the rear one is too far back to be of any use. No point in cooling the rear when it isn't used underway. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 604 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Gus Exactly what we do. Front A/C during the night when stopped and the rear one during the day when stopped. This gets the use shared as well. With the large windshield the fans mounted above the windshield sure help you keep cool when traveling. We also close off the rear louvers on the A/C unit to force all the air out the front of it towards the large glass area. | ||
| Derrick Thomas (Thomasinnv)
Registered Member Username: Thomasinnv Post Number: 41 Registered: 10-2010 Posted From: 173.143.60.251  Rating: N/A |
I have 3 13.5k units in my MC8. I only ever use 2. Just 1 in milder climates. Only time I have ever kicked on all 3 is when coming into a hot bus after being gone all day, just to cool it off faster. | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 743 Registered: 2-2001 Posted From: 184.0.13.120 Rating: N/A |
Two units up front is better. But I think you might want at least a 7K in the bedroom. When we stop for the night, the 1.5 tons of hot iron just on the other side of the wall/floor takes hours to cool. (We have a side aisle bus and not too much cool air gets around the corners). We also run the rear air while driving to keep the bedroom from getting hot as we travel. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1654 Registered: 10-2006 Posted From: 67.238.59.158 Rating: N/A |
With or without air , the rear area cools down far faster if the engine rear cover is open. First thing we do in a campground , pop the lid , check the oil. DD | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 2231 Registered: 12-2000 Posted From: 174.89.173.237 Rating: N/A |
Ditto. Open the engine room up once you are camped. Your choice, heat up through the floor, or out into the air? Of course, on a cool day, the reverse might be your strategy. happy coaching! buswarrior | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 39 Registered: 12-2011 Posted From: 99.100.88.196 Rating: N/A |
How big of a generator is required to run two of those 15,000 btu AC units? | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1432 Registered: 11-2005 Posted From: 173.202.29.62 Rating: N/A |
I also open the engine compartment immediately upon stopping in hot weather, makes a big difference. I also open the genset and water compartment doors since I have an engine water heater loop. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 610 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Scott I run 2 13.5k btu units on a 7.5 Onan. No problem so I suspect that 2 15k btu units would run on a 8 kw unit. Dick at Wrico is a great pearson to call for specs you might need. Bill | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 745 Registered: 2-2001 Posted From: 184.0.13.120 Rating: N/A |
I run everything in the bus at the same time on a 7.5 Onan Emerald. 2 x AC, water heater, small house fridge, lights, microwave, coffeepot & toaster oven. It would run 3 ACs (if we had 3) going down the road if the cooking & water heating stuff was turned off. | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 350 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
On my AMGeneral transit (which is very close to the GMC you have) I removed the A/C & heat, keeping the rather large heating core and mounting it length wise on the floor of the hallway with the closet and washer/dryer over. I power it with 2-14" 12v radiator fans and they just dump into the hallway with four vents. At the driver's seat, when I hear it come on, I can count to 10 and feel heat. I have a simple ball valve to turn it off, and the front defroster has a ball valve by the driver's seat. Mostly, the front defroster will keep the bus warm until the outside dips below 40. Then the big heater does the trick. I also have a manual switch for the heater booster water pump-but never seem to have to use it. Good Luck, TomC | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 71 Registered: 12-2011 Posted From: 99.100.88.196 Rating: N/A |
I only ran the bus for about 15 min, to test everything out. After getting the blower motor installed, and the new air filters in, and sealing up the undercarriage heater box that was missing 1/2 of it's rubber seal, the bus was kicking out 68 deg from the vents, it defrosted/demoistured the windows, including side windows. the bus had air blowing out of places I have never seen it blowing before. It was 38 deg outside. It was barley warmed up so I'm confident that it when on the open road it will have some kickin heat now. | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 2244 Registered: 12-2000 Posted From: 174.89.178.23 Rating: N/A |
Yup, nothing like a properly working stock HVAC system! Keep up the good reporting! happy coaching! buswarrior | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 73 Registered: 12-2011 Posted From: 99.100.88.196 Rating: N/A |
Last night I was installing seat belts... And wouldn't ya know it two of them need to be put right over that stupid heater box that I just was just in. It's like what 40 bolts to drop that box cover and I had it off for a week and 12 hrs after putting it back up I have to drop it again.... That's some funny crap. Laughter is what makes working on your bus fun. | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 81 Registered: 12-2011 Posted From: 12.107.220.154 Rating: N/A |
One of the things I did when trouble shooting was to crank up the temp setting on the graduatat.. It was 32 and I need to crank that puppy back down it got a bit to warm even with the driver heat off. But it's all working great. | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 1613 Registered: 3-2007 Posted From: 76.4.123.74  Rating: N/A |
Scott cut you a trap door in it and put the bolts in that way!! Much easier I think LOL Gomer | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 1449 Registered: 11-2005 Posted From: 173.202.31.183 Rating: N/A |
I can only leave mine on for about five minutes, much too hot otherwise. I've tried closing the rear valve down but that doesn't seem to make much difference so I just use the on/off switch. | ||
| Scott Crosby (Scott_crosby)
Registered Member Username: Scott_crosby Post Number: 84 Registered: 12-2011 Posted From: 166.137.15.134 Rating: N/A |
It sure was nice to have heat when it was freezing cold outside... But. not much when it's 70 outside. Also I guess I need to tear all the heating vents out and get rid of that foam insulation that's in them. It flies out this gritty little chunky pieces every where. When you touch it it disinigrates, but it's. A hell of a mess. Its probably toxic, carcinogenic, & a banned substance now anyway. I will say that since this is my first warm weather drive that the vents above the windshield are amazing for cooling and creating airflow. A/C has moved up my priority list though, after only 10 min of driving into the sun in +70 deg weather. And windows that don't leak while parked in the rain at home probably leak while driving in the rain, especially when vehicles passing create an air pressure wake of spray. I never drove in heavy rain at highway speeds before my trip this week, and it rained for 2 days straight non Stop. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 631 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Scott The biggest problem I have with rain coming in is the vents above the windsield. The foam seal hardens with age and the sealant under the housing that holds the lift up door drys out. It is easy to replace after you remove the two nuts on each one. The foam weather stripping is 5/16" thick with an adhesive backing on it. The force of the wind and rain is really pushing on these at highway speeds. Bill |
