So my brake lights stay on.....

[scramHD]

and traced problem to the brake switch. Well when I looked under the dash at the switch mechanism, I noticed fluid coming from the piston at the firewall. (what the switch pushes)....

What is this and what fluid is it ?

Thanks

 

[TannerJP]

Well...... I'm not fully sure.
We have what's referred to as a hydro-boost system that runs off power steering pressure.

It looks like there would be a seal on the very back of the booster for the pedal rod (seen as a cylinder with an eyelet at the inside firewall). That could be passing power steering fluid i believe. You may be able to take apart the booster and replace only that seal. I have an old book with an exploded view of a hydro-booster and R&R instructions if you decide you wanna try it out.

the brake switch (assuming power steering fluid is conductive) could be shorting?
or it could just be stuck... i haven't looked at how they are made and oriented on our trucks.
The one's i have seen are just push button switches.

Best of Luck.

 

[scramHD]

Twice now Ive had to play with the switch to get the brake lights to turn off. The pedal has some left/right play in it also. This has gotten worse over the last couple days but while coming off freeway and applying brake pressure, I get massive shake from the rear of vehicle. Front pads/rotor replaced. Rear are original. 221k.
Wasnt there a TSB on the hydroboost system?

If you dont mind Ill take a look. PM me. Thanks