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School Bus Transmission Oil In Coolant Repair

Cooling System Disassembly – Remove Radiator

To improve access to the radiator we removed the hood, charge air cooler and radiator assy. Before installing a new radiator the cooling system needs to be flushed out properly. The local rad repair shop recommended a low suds dishwasher detergent.

“Calgonite” for instance would work in this case. It would act as a degreaser and remove the sludge properly. This would require several flushes to do a proper job. The floor heaters go right to the very back of the bus using one inch heater hose to move the coolant so a good flow of water would be required to get through the entire circuit.

Transmission Evaluation – Damage Control

Typically if the driver had not noticed this failure right away we might be considering replacing the transmission (Allison New World 3000 Series) with a remanufactured unit. Since he shut it down immediately we are going to flush out the old oil and see if we can’t put it back into service. The coolant could have contaminated the clutch packs but we’re ready to try and see how the transmission works when we put it back on the road.

The reman replacement cost is just under 5,000 dollars… so if plan A works out we would be very happy about that. I’m relying on the synthetic oil we use in all of our automatic transmissions to pull us through. It’s a shame the cooler failed because there was absolutely nothing wrong with the transmission before all this happened.

Sticking To Plan “A”

A couple of trans oil changes will be well worth it if we don’t have to go to the more expensive Plan B strategy. The fleet costs need to be reduced when the opportunity arises so with the small cost in labour and oil to get this bus up and mobile again is well worth it.

Please feel free to comment…I would love to get your feedback.