Troubleshooting an Actuator that Leaks from the Reverse Lock Out Solenoid

Updated 03/08/2022 | Published 03/03/2022

Question:

My old actuator, the brake line screwed into the solenoid. Ordered a new one, and the brake line screws into the cylinder, but leaks. I Dont believe it screws in far enough before it bottoms out.

asked by: Monte K

Expert Reply:

There are a couple options that could be causing this issue with your Replacement Master Cylinder Assembly # DX44FR. The first would be an incorrect fitting. The female brass fitting exiting the solenoid or master cylinder body of the K71-757-00 (DX44FR) is a 3/16” inverted flare fitting which is a US standard “straight” male metal brake line or male brake hose thread. The female “cone” inside the inverted flare fitting seats and seals on the male cone inside the solenoid female fitting.

What can be confusing is that a 1/8” tapered male pipe thread fitting (which would be incorrect) will also easily screw into that fitting but will never seal. If this is the size of fitting you have, this would be the issue.

Otherwise there have been some who have experienced some inverted flare brake hoses and lines that were manufactured incorrectly with the wrong sealing angle on their ends. That might also be the problem.

The correct fittings should seal with five foot pounds of torque, so you will want to check and ensure you have the correct size fittings. Excess torque will ruin or break off the fittings.

expert reply by: Scott S