Abstract: A warning device for detecting mineral oil impurities in the brake fluid of hydraulic vehicle brake systems is described. The warning device comprises a body which is arranged in the brake fluid and can swell as a result of mineral oil and the change of shape of which indicates the presence of mineral oil impurities. The indication is given particularly as a result of the fact that the change in shape brought about by the swelling causes the opening or closing of an electrical circuit and thereby actuates a visual or acoustic indicator in the dashboard of the vehicle.

Abstract: An air-compressing four-cycle reciprocating piston injection internal combustion engine forming a driving engine of a motor vehicle, to which is flangedly connected a transmission by way of a clutch; the connections between the internal combustion engine and the clutch and/or between the clutch and the transmission are provided with such reinforcements that the natural frequencies of the oscillatory system, which includes the masses of the internal combustion engine, of the clutch and of the transmission, are higher than the frequencies of the dangerous exciting oscillations caused by the internal combustion engine constructed as five-cylinder in-line internal combustion engine which cannot be compensated for with the use of acceptable expenditures.