Transbrake issue
 

I have a 92 Mustang, 302 FI C4 (reverse valve body w/air shifter) in SS. Had trans rebuilt over the winter. Ever since, transbrake isn't working correctly. Voltage was checked, solenoid works, transfluid pressure was checked. First run of the day everything works fine but on subsequent runs, transbrake doesn't hold and I go through the lights. Happened yesterday again at LVD. Anyone ever have this happen? Valve body issue? Thanks for replies.

Re: Transbrake issue
 

I had a hipster solenoid roll pin, started backing out, and sometimes it would catch not engage, engage or get stuck. Not sure if your trans brake even has a roll pin in the solenoid but definitely something to check.

Re: Transbrake issue
 

In my SS car I had a similia issue.
Turned out that I had a leg strength issue.
I am 75.
I had to lower the pressure switch a lot to
compensate.

Re: Transbrake issue
 

Bob it sounds like you have a rear band servo seal that is leaking .It probably works on the first hit because the fluid viscosity has not thinned out yet. how does reverse feel once the fluid is warmed up after the first run?

Re: Transbrake issue
 

Whose valve body, internal or external trans brake selenoid and does the trans work fine when not using the trans brake? Can you hold it with the foot brake?

Re: Transbrake issue
 

Also make sure your air bottle has enough C02, might have enough pressure in the bottle first time out but loses air pressure? Maybe an air leak? Consider switching to an electric shift instead of air shift, I did and much happier.

Tim Stickles

Re: Transbrake issue
 

John we ain't old we are just "seasoned"! :)

Re: Transbrake issue
 

Go through the lights, I'm guessing you go forward when on the TB. Does it hold at all or does it roll forward as soon as you take your foot off of the brake? I'd check the wiring first to make sure the hot solenoid isn't showing a fault in the wiring. 2 wire solenoid? Where is it grounded?