Electric Over Hydraulic Brake Actuator for Trailer Drum Brakes

Question:

Was is the max flow volume for a single application of the K71-651 and the K71-650. I would pefer to order the K71-651 for the higher pressure capability but the 650 may supply the volume that I require. I intend to mate the unit with a pair of 13 uniservo drum brakes.

asked by: Bill O

Expert Reply:

Since you have drum brakes, you would have to use the Dexter Electric Over Hydraulic Brake Actuator, # K71-650, rated for 1000 psi. This actuator has a check valve that supplies a little bit of pressure on the wheel cylinders that allows the drum brakes to function properly.

For a single axle (2 brake assemblies) if both brake assemblies where identical, the pressure would be split evenly. However, it is more likely that one brake assembly will require more pressure than the other. Basically, each assembly would get the amount of pressure it requires to work properly.

A unit designed for disc brakes does not have this valve so the drum brakes cannot function properly. The 1,600 psi on the disc brake actuator allows the brakes to operate a little easier.

expert reply by: Michael H