Defrost improvement

[Byrd Scheit]

I got a 90 international. I am not liking this defrost/heater but Ill try it again after I clean it up.
Anyways has anyone blocked off the outside air intake and mount an electric fan in there? 8 x 18 inch space on the scoop above the radiators so two 8 or 6 inch fans will fit.
Doing this will move hot air at red lights and more at low speeds.
Mine has the old water knob mounted in a poor spot so flipping a switch would be easier and quicker.

[cadillackid]

ypour drfroster has a blower inside that should move tons of air unless the coils are clogged up or the fans are dirty / motor is bad.. this is an often case with busses.. im assuming this is a bluebird from the look of the covers.. have you checked both sides of that coil and the fan wheels for dirt?



bluebird usually has fan motors on both sides of the bus.. in that driver console and inm the right side system as well... theres no need for a fan in the air intake, the inside blowers when working right move lots of air..



I installed electric valves on one of my busses so i can flip a switch to engage the heater water flow or cut it off.. on one bus I completely ripped out the factory driver box guts and installed a Heating and A/C systtem for the dashboard inside the OEM cabinet which works much better

[Rwnielsen]

My bluebird had a filter, near the entrance, that had pretty much disintegrated. I spent about an hour with a piece of wire digging out all the clumps of foam. You might have something similar to that. They're available as a replacement.

[Byrd Scheit]

It is a blue bird
With all the mess I didnt notice the snail fan up front, towards the firewall. There are some cut wires that could have been for a second one. No filter or remains of one.
So clean it out, pressure test and electrical test.
Any ideas on the psi? Im guessing it should hold the same as the radiator.

[cadillackid]

the switches on the switch panel also help to determine how many fans you had originally.. if the bus wasa southern bus it may lack in defrost fans.. ive seen busses that just had a driver heater and defrost and not even a right WS defroster or rear heater..



the heater core would pressure test to same PSI as radiator cap.. seems on most diesels it calls for 7-10 PSI cap.

[Byrd Scheit]

Surprise surprise there is a rat nest inside the front fan that leads up to the defrost. Lots of cleaning and new hoses should fix everything

[magnakansas]

I helped on the front blowers, heater’s defrosters. We replaced one of blowers, all of the air duct hoses. Lots of vacuuming. Replaced wiper arm assemblies. And wiper arm mounts. We spent a whole day working on just the front of the bus.

William

[cadillackid]

first chilly morning out with my Superior this morning and im happy to report I was roasty toasty warm!. last year I completely restored the right side heater and right WS defroster.. (incidentilly right-heat is considered OPTIONAL on school busses.. and that includes right Windshield defrost.. )..



ive had questions from some of my friends newly into the vintage-bus hobby (yes there are other wierd ones like me that only buy busses WITH seats and intend on keeping seats).. they ask me why their right side heaters are removed... when in reality many iof us strive to buy busses from the south or desert states ..where likely the busses were bought with ionly the basic heating system and nothing more..



this went well into the 00's (and even today to some extent...). I recently looked at a 2003 Bluebird that had no right side heater unit at all.. and though it had defrost vents, with no extra unit on that side, the flow over the right windshield was lackluster. the bus spent its life in lower georgia (so it had nice A/C)..

this spring I completely restored the left side driver heater box guts.. vacuumed. foamed the coal, and replaced all but one motor (heater motors were on back order and it still works so I didnt change it).. the thing I have noted is the new motors ive put in all pull just a tad less current than the old ones and blow out probably 40% more air.. the old motors ran but just not well...



Superior branded busses were noted for having some of the best Heat and Defrost in the business back in the day.. there are 3 blowers just in the driver box and 2 in the right-side unit..



I buy all my heater motors from TAC bus parts and they seem to be good ones.. they sell universals which are really powerful and can be reversed to match the unit you are putting them in.



was nostalgic this morning hopping on that bus like i did as a school kid and remembering how loud it was up front from all the fans on cold mornings..



one of the blowers, blows heat down the channel where the heater hoses are and has vents every 8 inches or so.. goes down halfway or a little more the length of the bus.



bluebird had a similar setup if you ordered it extra...


the quality of your heat and defrost upfront is partly making sure the system works properly but it can also be dependent on the options the schools ordered..

[DeMac]

Originally Posted by cadillackid

first chilly morning out with my Superior this morning and im happy to report I was roasty toasty warm!. last year I completely restored the right side heater and right WS defroster.. (incidentilly right-heat is considered OPTIONAL on school busses.. and that includes right Windshield defrost.. )..



ive had questions from some of my friends newly into the vintage-bus hobby (yes there are other wierd ones like me that only buy busses WITH seats and intend on keeping seats).. they ask me why their right side heaters are removed... when in reality many iof us strive to buy busses from the south or desert states ..where likely the busses were bought with ionly the basic heating system and nothing more..



this went well into the 00's (and even today to some extent...). I recently looked at a 2003 Bluebird that had no right side heater unit at all.. and though it had defrost vents, with no extra unit on that side, the flow over the right windshield was lackluster. the bus spent its life in lower georgia (so it had nice A/C)..

this spring I completely restored the left side driver heater box guts.. vacuumed. foamed the coal, and replaced all but one motor (heater motors were on back order and it still works so I didnt change it).. the thing I have noted is the new motors ive put in all pull just a tad less current than the old ones and blow out probably 40% more air.. the old motors ran but just not well...



Superior branded busses were noted for having some of the best Heat and Defrost in the business back in the day.. there are 3 blowers just in the driver box and 2 in the right-side unit..



I buy all my heater motors from TAC bus parts and they seem to be good ones.. they sell universals which are really powerful and can be reversed to match the unit you are putting them in.



was nostalgic this morning hopping on that bus like i did as a school kid and remembering how loud it was up front from all the fans on cold mornings..



one of the blowers, blows heat down the channel where the heater hoses are and has vents every 8 inches or so.. goes down halfway or a little more the length of the bus.



bluebird had a similar setup if you ordered it extra...


the quality of your heat and defrost upfront is partly making sure the system works properly but it can also be dependent on the options the schools ordered..

----------------------------
Yes, Christopher. Our FL bus came with a driver's core only. Triple ACs, but no pax heaters or door defroster.


Three vents tied together with a "T". No heat or fan. Just a big hole underneath.


The bezel of the faux door-defrost hides this (11"x19") asphalt window, exposing the headlight housing, pavement and wildlife below.


The factory installed heater hose chase & heater core can become a wildlife preserve.


We chose to seal the holes. No intention of adding heaters or traveling north. (Not recommended for most)

[Gorzie]

I have a similar issue but I have redone all the hoses and filters. I did notice that one of the resistor wires is bad. On the low fan setting it does not turn on but on high the fan runs. Do you think this could be the cause? It is the large double squirrel cage fan which I imagine should be moving a bunch of air.

[white_whale_express]

I have a 2001 Thomas I'm hoping to replace the defrost air hoses and Y connectors with new ones. (I did try cleaning them but they feel like a lost cause with those ridges I can't get in there to clean the inside of the hoses thoroughly) In searching for replacements (3" ID) I can't seem to find a direct replacement. Any suggestions on where to search?

[cadillackid]

3" flex A/C hoses are easy to find..



here is one type.



https://nostalgicac.com/duct-hose-ve...duct-hose.html


here is one if you want to rebuild your dash and add your own vents..


https://www.jegs.com/i/JEGS/555/70606/10002/-1