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 08 Vision coolant circulation
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Cal Mc
Advanced Member

245 Posts

Posted - 01/18/2014 :  06:58:12 AM  Show Profile  Visit Cal Mc's Homepage  Reply with Quote
2008 Vision/ Cat C7 ACERT

After 1 1/2 hours of operation the bus looses coolant circulation in the heating system. At 1/2 an hour of operation the air from the defrost is hot enough that a hand 3 inches from the vent does not stay long.
I have replaced themostats, waterpump,isolated and evacuated the heating system and done a coolant flow test. I pulled in a sister chassis and did the same coolant flow test in the heater circuit for comparison.
I have run the bus up to 190F with a clear tube placed in series with the supply to the heaters from the engine, with no large amounts of bubbles showing. The original fittings on the engine for the supply to and return from the heaters had a 3/8" hole through the smallest fitting. They has been changed to fittings with a 1/2" hole.

With temperatures around the freezing mark it is not a big issue. There is enough heat retained in the body to finish the route. When temperatures drop to 0F and colder we do get complaints.

Any suggestions would be appreciated.

Thomasbus24
Administrator

USA
3320 Posts

Posted - 01/18/2014 :  4:23:52 PM  Show Profile  Reply with Quote
Booster pump finally tripping breaker and restricting flow? Just a thought.

Also, do Visions use an electric valve to start and stop flow like the AAFEs do? Had a 2012 randomly shutting off flow on us, turns out it uses a temp sensor that only allows the valve to open up after the coolant hits a certain temp and that sensor was bad. If you have such valve, I'd open and unplug it for a day.
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Cal Mc
Advanced Member

245 Posts

Posted - 01/18/2014 :  8:56:37 PM  Show Profile  Visit Cal Mc's Homepage  Reply with Quote
No valve in system and no booster pump 2008 bus has heated fine till the last month. Thanks for the response.
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busman01
Active Member

15 Posts

Posted - 02/04/2014 :  04:00:29 AM  Show Profile  Visit busman01's Homepage  Reply with Quote
Hey Cal Mc-I was wondering if you were able to determine the cause of your heating issue? We have a 08 Vision w /the Cat that is doing something very similar to what you describe w /yours.Thanks :)
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earl1412
Active Member

23 Posts

Posted - 02/04/2014 :  07:50:18 AM  Show Profile  Visit earl1412's Homepage  Reply with Quote
Cal Mc, have you checked for dust and debris on the respective heat cores? I have found that especially true for the drivers core.
earl
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05ICCE
Senior Member

USA
67 Posts

Posted - 02/04/2014 :  5:53:29 PM  Show Profile  Visit 05ICCE's Homepage  Reply with Quote
Does BB use a heat control valve like IC? We had a valve in our 06 IC CE come apart internally and block coolant flow to the rear heater but had defrost and most driver heat. Our valve is located to the left of the driver.This is a mechanical valve, not electric.

Mr. Scott, "because he drives a COOL BUS"

Edited by - 05ICCE on 02/04/2014 5:54:40 PM
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bwest
Administrator

United States
2296 Posts

Posted - 02/04/2014 :  8:02:15 PM  Show Profile  Reply with Quote
I've been thinking about this. You didn't say anything about the temp. I am assuming it is normal. If you're in a cold climate I am suspecting a faulty water pump on the engine. Maybe an impeller loose on the shaft. I would speculate that there is enough coolant flow in extreme cold to cool the engine but not enough to get into the heating system after the initial warm up. Just a theory. Let us know what you find. If it's like I run into it's probably something simple, I'm always making things hard!

Bryan
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Tb4020
Senior Member

United States
65 Posts

Posted - 02/05/2014 :  06:43:28 AM  Show Profile  Reply with Quote
Bluebird doesn't have a valve on the visions like Thomas or IC I would lean toward the water pump also, it seems our Cats of that vintage need water pumps every two years leaking seals or bearings. None of ours have assist pumps and will roast you out on the coldest day, I have had some that need to be bled for no apparent reason make sure the coolant res. is full and try bleeding the system good, check the temp with a temp gun the sensors have been known to lie then it will run the fan clutch constantly. That bus should make 210 easily, the coolant should squirt out from the bleeder fitting at an idle.
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Cal Mc
Advanced Member

245 Posts

Posted - 02/09/2014 :  2:54:56 PM  Show Profile  Visit Cal Mc's Homepage  Reply with Quote
Engine temperature is excellent(new thermostats).Old waterpump looked perfect, but I put a new one on from Caterpillar. I put a temp gun on to the hoses and heater cores. When the coolant quits circulating both cool off quickly.The system only uses 1/4 turn ball valves.We installed coolant filters(2) on the bus two years ago and they were changed when the water pump was replaced.

UPDATE;
This week we had two days of non-operation due to cold weather(-35C)so I had time to spend with the bus. In desperation I stripped out all of the heater hoses under the hood and in the passenger compartment. The hoses were all replaced with new hose. After a two hour test drive I had no failure in circulation. I am going to wait for the weather to warm up and try it again before concluding that I have solved the problem.

We have had problems with silicon hoses having internal cracking and separation in the past. I suspect that there may have been an offence of this nature causing the problem.

Edited by - Cal Mc on 02/09/2014 3:03:04 PM
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bwest
Administrator

United States
2296 Posts

Posted - 02/11/2014 :  06:31:26 AM  Show Profile  Reply with Quote
quote:
Originally posted by Cal Mc

Engine temperature is excellent(new thermostats).Old waterpump looked perfect, but I put a new one on from Caterpillar. I put a temp gun on to the hoses and heater cores. When the coolant quits circulating both cool off quickly.The system only uses 1/4 turn ball valves.We installed coolant filters(2) on the bus two years ago and they were changed when the water pump was replaced.

UPDATE;
This week we had two days of non-operation due to cold weather(-35C)so I had time to spend with the bus. In desperation I stripped out all of the heater hoses under the hood and in the passenger compartment. The hoses were all replaced with new hose. After a two hour test drive I had no failure in circulation. I am going to wait for the weather to warm up and try it again before concluding that I have solved the problem.

We have had problems with silicon hoses having internal cracking and separation in the past. I suspect that there may have been an offence of this nature causing the problem.



That is good to know! I have never had this problem but I do have some issues with poor passenger compartment warm up. I'm wondering now if I need to be changing some hose.

By the way, THAT'S COLD!!! Had to convert it to F to understand it. Never witnessed that before. Coldest it's been here is -15F. It really depends if the wind is blowing on how cold that really is but needless to say that is cold!

Bryan
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