| Author | Message | ||
| Moti Nowrangi (Mnowrangi)
Registered Member Username: Mnowrangi Post Number: 7 Registered: 2-2009 Posted From: 96.255.83.117 Rating: N/A |
....another 1974 MC8 question,... Where does one add additional Coolant or Freon? I noticed on the passenger side, rear to the bus way on top is the receptacle for which to add - coolant? or Freon? I haven't seen a sight-glass which will enable me to see if the level is adequate. Do I top of until I can visibly see it coolant at the opening or will the excess fill up a reservoir somewhere (where is the reservoir located?), and/or drain of into the ground under the buss? I am assuming that coolant is what I add myself - where does the Freon go? Cheers! | ||
| David Dulmage (Daved)
Registered Member Username: Daved Post Number: 237 Registered: 12-2003 Posted From: 142.46.199.30  Rating: N/A |
Coolant, which should be a 50/50 mix of diesel engine anti-freeze and de-ionized water, is added at the inlet at the upper right rear of the coach. Freon should be added to the air conditioning system at the appropriate port at the A/C compressor. In many jurisdictions, due to environmental regulations, this needs to be done by a qualified air-conditioning technician or a mechanic with a current air-conditioning service certification. DaveD | ||
| Moti Nowrangi (Mnowrangi)
Registered Member Username: Mnowrangi Post Number: 13 Registered: 2-2009 Posted From: 96.255.83.117 Rating: N/A |
Is there a surge-tank where the overflow flows into? And if so where is it located? Or does the excess just drain off on to the road when topping off? | ||
| John MC9 (John_mc9)
Registered Member Username: John_mc9 Post Number: 844 Registered: 7-2006 Posted From: 74.162.92.56  Rating: N/A |
Re: "I noticed on the passenger side, rear to the bus way on top is the receptacle for which to add - coolant? or Freon? I haven't seen a sight-glass which will enable me to see if the level is adequate. " The coolant sightglass is usually between the two "hamster cage" fans. Do they look like this? (note the highlighted area)  | ||
| Moti Nowrangi (Mnowrangi)
Registered Member Username: Mnowrangi Post Number: 14 Registered: 2-2009 Posted From: 96.255.83.117 Rating: N/A |
Thanks for the picture - yes it resembles my 1974 MC8. The sight glass is just beneath that large pulley between the blowers - I think that the horizontal frame in the picture is hiding its visibility. When doing my pre-trip, coolant is visible via the sight glass. If I were to "top off" by adding more coolant where does the excess go? Does it just spill out from the receptacle receiver opening in the top rear of the coach or is there a resevoir somewhere (if so where?) or does the excess overflow spill via hosing to the ground? I guess I have to just "top" off and see what happens??? Is there such a thing as adding to much coolant? | ||
| Ralph Peters (Ralph_peters)
Registered Member Username: Ralph_peters Post Number: 21 Registered: 12-2008 Posted From: 206.251.14.112 Rating: N/A |
The tank with the sight glass is a resevoir/surge tank. If the coollant level went low you may need to bleed the drivers heator. And keep a close eye on that sight glass. | ||
| Moti Nowrangi (Mnowrangi)
Registered Member Username: Mnowrangi Post Number: 16 Registered: 2-2009 Posted From: 96.255.83.117 Rating: N/A |
What is the process involved in bleeding? What are the tell-tale sings associated with this if any? | ||
| Grant Thiessen (Busshawg)
Registered Member Username: Busshawg Post Number: 124 Registered: 10-2007 Posted From: 206.45.93.160  Rating: N/A |
Your won't have decent heat inside your bus. The engine temp gauge my get very hot then cool suddenly as the air lock trys to move with in your system. If this is he case you should be able to add coolant as the air lock reaches the radiators as your coolant level will suddenly drop as the air comes up. Be sure to add hot coolant if your engine is hot. If your engine only over heats and does not cool down the air lock isn't moving and would require bleeding. I believe your coolant would have to very low before you would need to bleed. I replaced both of my radiators and didn't need to bleed the system. I had closed both of the valves that supply the heater core with coolant by the engine before i drained my old rads. I believe some of your problem will be solved once you find the second coolant valve near the top of your transmission, if it is closed you will not be getting any interior heat as the coolant isn't circulating | ||
| Bruce Henderson (Oonrahnjay)
Registered Member Username: Oonrahnjay Post Number: 380 Registered: 8-2004 Posted From: 76.21.223.54  Rating: N/A |
Grant said "I believe your coolant would have to very low before you would need to bleed." Yes, I didn't mean that I thought it was necessary to bleed but mentioned it as an example of the possible things that could be going on. And I don't even know if the original poster's bus has a bleed system. Sorry if it was all too specific in a general discussion. | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1521 Registered: 12-2000 Posted From: 76.68.120.176  Rating: |
Are you looking at the sight glass for the blower gear oil level or the sight glass on the rad overflow tank? Lots of this vintage MCI did not have sight glasses on the overflow tank, you fill via the filler neck high on the side of the bus, and stop when it is full. Are you aware of the amount of freon you need to charge this bus? Depending on which type you use, 20 to 25 pounds, you aren't filling this with cans from Pep Boyz.... If your HVAC system is functioning correctly, you leave the water valves open at all times. The system regulates itself, and needs the heat to make the AC work right. Never mind the yik yak to justify your lack of knowledge, buses are new to you. If you didn't know, you have stumbled on one of the two greatest concentrations of bus and coach knowledge on the internet. This site is privately owned and hosted. No worries, we'll be happy to share, if you want to learn. Now, young Skywalker, if we tell you you need the manuals, WE MEAN IT! Check the classifieds on this site for current suppliers. There are three for that coach, an Operator's Manual, a Maintenance Manual and a Part's Manual. If you are putting a scare into some folks on this board, it would be wise to think hard about what "natural selection" means, and whether you, your business and your passengers, are on the way to becoming a statistic. happy coaching! buswarrior | ||
| Moti Nowrangi (Mnowrangi)
Registered Member Username: Mnowrangi Post Number: 22 Registered: 2-2009 Posted From: 96.255.83.117 Rating: N/A |
Thank you! You're my new friend! Two of the three manuals are available from MCI with the exception of the Operators Manual - that is out of print. I do have the Parts Manual and will order the Maintenance Manual. Cheers! | ||
| Tony LEE (T_lee)
Registered Member Username: T_lee Post Number: 50 Registered: 11-2007 Posted From: 195.23.214.142 Rating: N/A |
Are you talking about freon that is used to charge the refrigerated AC system, or do you mean the antifreeze stuff (glycol???) you mix with water and use in the radiator? |
