my brakes went out

[BlackVert]

i got in my car last night to go somewhere, and i pulled out of the driveway and when i hit the brakes, the brake pedal was really hard to press and the car barely stopped. the pedal didn't go to the floor, it was just really hard to push.

they were fine coming home a few hours earlier. nothing out of the ordinary.

i checked the brake fluid level. fine, no leaks.

i checked the fuses in the engine bay, none blown.

i have not checked the fuses in the passenger compartment.



brake booster?

 

[harrisonfiveo]

CHECK AND SEE IF YOUR VACUUM LINE TO THE BOOSTER IS STILL ATTACHED...

 

[BlackVert]

here is a crude drawing of part of my vacuum routing

the pcv and canister purge solenoid are connected to the vacuum line from the intake to the tree with simple T vacuum connectors. i color-coded it to make it easier to see.

would a break in the canister purge tube explain the problem i am having with the brakes?

i probably should re-do it so that the vacuum source to the tree is isolated ...

 

[BlueOvalStangGT]

Whats the canister purge solenoid look like and what does it do?

 

[BlackVert]

Whats the canister purge solenoid look like and what does it do?

i'm not really sure what it does ... some emissions thing to catch gas fumes or something like that.

 

[HISSIN50]

Yep, the canister purge sends collected fuel vapor from the charcoal cannister and sends it into the intake. This is a means of venting the gas tank, but as a closed system (no more open venting of gas fumes).
And a leak in that purge solenoid line can cause issues - you would have a large vac leak and the booster would not be able to assist as much as normal. BUT THAT DOES NOT MEAN THIS IS THE ISSUE. I would thoroughly inspect the brakes nonetheless.

The lines on the purge solenoid do vulcanize. I replaced the one from the solenoid to the Tee behind the intake, and I need to remove the fender liner and take care of the other one, as well as all other lines in the fender.

Good luck Chris.

 

[BlackVert]

Yep, the canister purge sends collected fuel vapor from the charcoal cannister and sends it into the intake. This is a means of venting the gas tank, but as a closed system (no more open venting of gas fumes).
And a leak in that purge solenoid line can cause issues - you would have a large vac leak and the booster would not be able to assist as much as normal. BUT THAT DOES NOT MEAN THIS IS THE ISSUE. I would thoroughly inspect the brakes nonetheless.

The lines on the purge solenoid do vulcanize. I replaced the one from the solenoid to the Tee behind the intake, and I need to remove the fender liner and take care of the other one, as well as all other lines in the fender.

Good luck Chris.

thanks. i'll fix it up and isolate the line to the tree. i'm sure that is the problem, but i'll ask my mechanic to check when i take it in just to be sure. i don't want to take any chances with the brakes.

mine WAS vulcanized and i replaced it all the way to the box back by the door in the fenderwell when i did the vacuum tubing.

 

[BlackVert]

I replaced the one from the solenoid to the Tee behind the intake

just curious, which line was it Tee'd in?

 

[yellow1995Cobra]

You should have a heavy gauage vac line coming off the intake to the brake booster itself, or to the tee. You dont want alot of things drawing off the same vac line as the booster, thats for damn sure. My friend routed his vac lines incorectly once, just much stuff on one little vac line off the intake, and the brake pedal acted like you said.

 

[HISSIN50]

just curious, which line was it Tee'd in?

Chris, my apologies. I knew there was a connection made with that line behind the EGR valve, and I thought it was a tee. But it simply is an inline junction to join two hoses together. It might not even be OEM - someone might have done that on my car if they did not want to replace a whole run of vac line. No tee.

 

[BlackVert]

You should have a heavy gauage vac line coming off the intake to the brake booster itself, or to the tee. You dont want alot of things drawing off the same vac line as the booster, thats for damn sure. My friend routed his vac lines incorectly once, just much stuff on one little vac line off the intake, and the brake pedal acted like you said.

sure enough, that was the problem. i moved the solenoid line somewhere else and now it is just the pcv and vacuum tree on the big hose. as time permits, i plan to redo the pcv line too so it is just the big hose straight to the vac tree. that is probably the safest.