Trailer Brakes Question

Ouh, really I cant find diagram of so old trailer. but as I remember in 80-s no park brake release valve was required, so if you loose red glad hand with modern trailer it applies service brake immideatly (not spring brake, to avoid wheels lock), old - with some delay.



This is diagram of old (70s) MAZ costenoga made with old standards.

They used very simple trailer valve with protection but no park brake accelerator.


I sugest this trailer is so old that so simple things are used, so It would be normal.


P/S MAZ used Wabco components in 70-s, but Bendix made air valves according the same laws in 70-s

 

If air is coming back up line to the as you call it glad handle and you have a yard release valve on trailer somewhere, don't know if you have them over there. It will be that button brake release valve.

 

old trailers had no button. pushbutton appeared in 90s. Why? to use ro ro trucks. Trucker drop trailer in sea terminal with air in tank, and terminal truck hooks it connecting no air lines, so they use buttons to release park brake if there over 90 PSI in trailer air tank

 

So, have you fixed the problem?