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kd4jfd
Top Member
USA
1136 Posts |
 Posted - 01/10/2012 : 7:21:15 PM
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| I have a '96 BB TC 5.9 Cummins that is loosing about 2 quarts of coolant a day. The mechanic has replaced the cap 3 times and the last time it helped to recuce the loss to about 1 quart. It appears to be blowing it out the cap and overflow tube. The cap is a 10 lb. Any suggestions/helpful comments? |
539 - Repair work in progress! 349 for sale!SOLD!for sale!sold? SOLD and GONE!
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Thomasbus24
Administrator
USA
3175 Posts |
Posted - 01/11/2012 : 05:24:09 AM
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Sounds like a head gasket. A guy can fill the system up, then put a pressure tester on (instead of the cap), then go in a start the engine. I'd imagine you'll see the pressure begin to rise right away. That's how we find 'em anyways.
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wrenchmen
Senior Member
USA
115 Posts |
Posted - 01/12/2012 : 12:41:58 PM
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If this bus is equipped with Air Brakes, it could also be the air compressor head gasket.
Test in the same manner as above but with the air tanks full and engine off.
Gauge will rise as air pressure from air brake system leaks into cooling system. |
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Thomasbus24
Administrator
USA
3175 Posts |
Posted - 01/12/2012 : 1:32:06 PM
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| Very good point about the air compressor! |
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C.HARDY
Advanced Member
260 Posts |
Posted - 01/12/2012 : 2:24:32 PM
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| You can rev the engine up with the cap off and see if coolant blows out. |
"Hardybusman" |
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Crown
Active Member
40 Posts |
Posted - 01/16/2012 : 12:18:46 PM
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| We've had a few of those with leaking head gaskets. We think it traced down, in our case at least, to some new coolant that we were using. Putting assumption on top of assumption, we think the problem is fixed. |
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02raptor
New Member
8 Posts |
Posted - 01/27/2012 : 05:36:24 AM
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| Are you sure it is the cap? We have had to replace the plastic tanks on those and went to a steel tank. |
9 school buses.3 service vehicles.4 Tractors and Me. |
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bwest
Administrator
United States
1828 Posts |
Posted - 01/27/2012 : 07:15:11 AM
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| There is a test stip that will tell you if there is exhaust getting into the coolant as well. |
Bryan |
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JustinB
Advanced Member
United States
485 Posts |
Posted - 01/27/2012 : 2:47:06 PM
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| The strip will come back in technicolor on most any cooled EGR engine from the past 10 years. |
I may not know the answer but I can usually find who does. |
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Ron Maden
New Member
1 Posts |
Posted - 02/17/2013 : 11:33:43 AM
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| I had one with a bad head gasket on the compressor that caused the same problem. Now the same bus is loosing about 1 to 2 quarts a day with out any signs of leakage. |
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IBTMech
Top Member
USA
961 Posts |
Posted - 02/17/2013 : 4:38:10 PM
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| No external leaks. No unusual drainings from the air tanks. It's going out the tailpipe somehow. |
If it doesn't fit, FORCE it.
If it breaks, well, it needed replacing anyway.
Pullin' wrenches for 45 years. |
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kd4jfd
Top Member
USA
1136 Posts |
Posted - 02/24/2013 : 2:01:00 PM
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UPDATES: The mechanic put a 13 lb cap and it only needs to be filled about once a month.
Also, I got a 'promotion' - moved to a different route with less students and smaller bus with more hours. |
539 - Repair work in progress! 349 for sale!SOLD!for sale!sold? SOLD and GONE!
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Topic |
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coolant leak
