# Master Cylinder Repair  Air on Hydraulic



## ronjudi (Oct 29, 2014)

A few years back I ran across a posting on this forum about replacement of Midland Haldex power intensifier #N37216 and used that information just now to help me find my problem.   These things are expensive.   I found a company in St Clair Mo that rebuilds the units so the large expense of a new unit is avoided.  My front brake  intensifier on my 99 Gulf Steam Pusher developed a small leak visible at the weep hole of the air chamber on one of my two units.  This inspection was started as I got an occasional red light of the brake malfunction light until I pumped the brake pedal a few times.  I then proceeded to find which one was defective. A leak can be confirmed at the weep at the bottom of the air chamber which is just in front of the hydraulic piston.   This is where a brake fluid leak shows up if it should occur.   In my case the front brake unit weep hole was wet while the back brake unit was still dry.  There is also a indicator wire sticking out a hole on the end of the air chamber used to show the brake piston travel which if excessive is an over stroke caused by a leak. .   According to Haldex this  travel extension should be a maximum of 3/4 inches before the brake malfunction indicator will light.    If you find a leak you will be able to identify which unit is defective and is causing the red light illumination.

To update if you have problems with these units I located a company in St Clair Mo that rebuilds the units so the large expense of a new unit is avoided.  An employee at Haldex gve me the telephone number.    My coach mechanic also uses these folks which specializes in rebuilding several Haldex Units that are hard to locate.    The company is Precision Rebuilders.com.  These units for air over hydraulic coaches like mine are in short supply so if you have the problems as I did we now have an alternative.  Best of all they are reasonable.    800 325 2690  

Ron Davs


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