Cryo Rotors Tested on Huge Mining Truck
A client recently revealed an issue with the excessive wear on the service brake rotors and brake pads on the 730E Komatsu trucks in their fleet. As you can see, this is not your average pickup truck. It stands over 20 feet high and is almost 25 feet wide. It has an 1860 horsepower 16 cylinder diesel engine. It weighs 715,000 lbs when loaded, 310,000 empty. That is a lot of weight to stop from any speed.
Any down time with a vehicle like this is costly. Parts are expensive due to the size of the vehicle. The rear braking system consists of four 25 inch diameter brake rotors. These rotors cost over US$1500 each. In an attempt to solve the problem we Cryogenically treated and had installed a set of brake rotors to the LH side of one of their trucks in service. The RH side was fitted with a standard untreated rotor to give us a control.
After one month they were inspected and it was found that the Cryogenically treated rotor had no cracks and the untreated one had severe cracking to the braking surface. Also at this time the pads on our rotor had worn 1.5mm as apposed to 7mm on the untreated rotor.
The next inspection recorded was at 5 months. At this stage the Cryogenically treated rotor was still on and had developed some cracking but these were quite minor in size compared to the RH side. The right hand side had already had its second rotor fitted which was now cracked far more severely than our original one.
It is obvious to date that the Cryogenically treated rotor will outlast at least 3 conventional rotors and in fact will be monitored weekly just to see how far it will go before it needs to be discarded.
The deep and open cracking of the conventional rotor in such a short time will effect the pad wear considerably given the speed at which these rotors rotate in service which in this instance is 27:1 compared to the tyre rotation.
Treated Rotor After 5 Months of Use
Untreated Rotor After 2 Months of Use