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bob-kir's avatar
bob-kir
Explorer
Apr 04, 2020

Chevy C-5500 Kodiak Duramax potential safety issue!

I was recently returning home after spending the winter in Mexico in our 08 Seneca Duramax with 65,000 miles on it when I had an unexpected engine shut down!
I was driving about 63mph in the right lane in heavy traffic coming into St. Louis towing a car when a very loud continuous warning buzzer sounded and a couple of dash warning lights came on. I couldn’t tell what the icons on the warning lights represented but all of the gauges read normal. I was reducing my speed when the engine shut down, maybe 10 seconds after the alarm started sounding. Now I had no power steering or brakes. Luckily, I was right at the exit for a weigh station. I wrestled it over and got it stopped in the station truck parking area. Had to sit for a couple of minutes to calm down. It took considerable effort to just make the slight steering correction to enter the exit lane. Had I been on a curvy 2 lane road I don't know if you would be able to keep it on the road.
After stopping and checking the manual the warning lights indicated “low coolant” even though the dash temperature gauge was reading normal. I opened the hood and saw that the coolant reservoir was below the minimum level. Then I noticed coolant dripping from under the reservoir and saw that the hose that exists the bottom of the reservoir was about ready to fall off. It had slid down about 2 inches and was within a 1/4 inch of falling off completely. The clamp that holds it on is a steel compression ring with no way to tighten it. I slid the hose back to its original position and put on an additional hose clamp to secure it and added a gallon of water and we were go to go.
Before we leave Mexico I always do pretty thorough engine check , belts, hoses, fluid levels but never looked under the coolant reservoir to check the position of that hose. My guess is that the very rough Mexican roads were a factor in the hose coming loose.
I will always check that hose from now on!
  • Had this happen to a work truck, it would occasionally sound the alarms and die when taking a curve fast. Topping off the surge tank seemed to help until one day I could hardly drive the truck even with a full surge tank. I ended up replacing the sensor at the bottom of the surge tank, problem solved. You'll have to get the sensor from a dealer, the only place I could find it.
  • I replaced the complete tank on my 04 and friends 05. It was only $40.
    Not that price anymore. ACDelco 15161670 GM. Got it from Amazon. Did a quick check. Part # is good for 2003 to 2009.
  • Help me understand something... doesn't hydraboost utilize the hydraulic pressure from the power steering pump to "boost" the brake pedal? Is there actually an accumulator somewhere that holds some pressure to aid in braking once the engine is off?
    Gary
  • FunTwoDrv wrote:
    Help me understand something... doesn't hydraboost utilize the hydraulic pressure from the power steering pump to "boost" the brake pedal? Is there actually an accumulator somewhere that holds some pressure to aid in braking once the engine is off?
    Gary


    Yes, and yes--it holds some pressure both in case of the engine shutting off and in case of the power steering pump or its drive belt failing. The accumulator is sometimes incorporated as a part of the hydroboost brake booster unit itself, rather than being a physically separate component. It only provides emergency pressure for the brakes, not for the steering power assist.

    Here's some more general information, perhaps more than you really wanted, on the system.
  • Information above is good no how Hydro Boost works. On GM Medium Duty Trucks there is a difference. A electric pump is used to provide boost when power steering pumps fails or engine is not running. Here is picture showing master cylinder and pump motor.