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PortuguêsWhen the temperature of the hydraulic fluid is a problem
A few weeks ago, the Ciempozuelos-based company Excavaciones Lanchas e Hijos contacted our lubrication expert, Victor Alonso, from VICMAQ Suministros, with regard to a solution for the problems involving the hydraulic fluids they were using in their CATERPILLAR 318C excavator.
They reported that they were using a 46 HM hydraulic fluid of a known brand, and after having drained the system in order to collect a sample of the liquid, it was seen to be burnt, of a blackish-brownish colour, when it is originally crystalline to whitish.
The problem is obvious: the excessive operating temperature of the fluid due to inappropriate viscosity, aggravated by the poor quality of the product.
So, what´s the correct temperature for the hydraulic fluid used in my machine?The answer isn´t simple, as this depends on a number of factors ranging from the length of the hoses to the class of quality of the fluid... Many machines are equipped with a temperature gauge, calibrated at around 84 ºC, however this value is only correct for HLP, HV type fluids and superior, which contain additives that improve the viscosity/temperature ratio, in addition to increasing resistance in areas of friction.
HM-type fluids have few additive properties and behave like a monograde lubricant, and as such they lose viscosity and heat up even more when the temperature increases. Their operating temperature should be no greater than 70 ºC and to continue operating when the fluid has overheated will almost certainly damage the hydraulic pump pistons, and may even result in seizure.Once the burnt fluid in the machine had been replaced with our Maxifluid 68 HV, the system restarted with no problems and the first sensation was an increase in pressure and an enhanced response from the control commands, showing that we were working with the right product.After operating for a few hours, the temperature remained steady at under 80º C and the pump drive was normal, with no sign of a loss in pressure.
OLIPES Maxifluid HLP and Maxifluid HV are the professional ranges of hydraulic fluids, available in different ISO grades, adapted to the specifications of the principal manufacturers of heavy machinery and hydraulic equipment.
Tell us about your problem in an e-mail, addressed to our technical assistance department at: olipesresponde@olipes.com
We have over 2,500 lubricant products to ensure you always acquire the best solution.
