Car won't start brake pedal too stiff

danelonson · 08-03-2019, 05:52 PM

Tried starting my car this afternoon and when I pressed the brake pedal I noticed it was very stiff (never experienced this before) and the car won't start because the pedal doesn't go down far enough to engage the switch.

What could this be? I checked the brake fluid level and its at the right amount, could it be a vacuum leak? How could I detect which line is causing the issue?

Thanks guys!

danelonson · 08-08-2019, 08:58 PM

Bump for help

SouthArk370Z · 08-08-2019, 10:10 PM

The pedal is stiff because you have no vacuum. You won't have any vacuum until the engine starts. That doesn't mean you have a leak - still possible but low on my list - as, without the engine running, a press or two on the pedal will bleed off any stored vacuum.

The pedal doesn't have to move very far (less than an inch) to change the state of the switch. The switch could be the problem but, as with a vacuum leak, it's low on my list.

Get an OBD tool and see if any DTCs are present. Modern cars are pretty good diagnosticians.

Edit: Try shaking the shifter while starting the engine. There is a Park/Neutral switch that can keep the engine from starting.

danelonson · 08-09-2019, 02:04 AM

Thank you SouthArk for your help.

Do you think it could also be the check valve in the vacuum hose that's connected to the brake booster that is going bad?

SouthArk370Z · 08-09-2019, 08:15 AM

Quote:

Originally Posted by danelonson

Thank you SouthArk for your help.

Do you think it could also be the check valve in the vacuum hose that's connected to the brake booster that is going bad?

At this point, I don't think the brake system is a problem. It is normal to lose vacuum if you press on the pedal when the engine isn't running.

You can check the brake pedal switch with a cheap multimeter.

Check for DTCs.

AARONHL · 09-12-2019, 11:06 PM

Try engaging the switch with your hand while your start the car (maybe having a friend would help) And is your battery good? Are you sure you got enough power to start the car

08-03-2019, 05:52 PM	#1 (permalink)
danelonson Base Member Join Date: Apr 2012 Location: Florida Posts: 82 Drives: 12 370z 7AT Sport Rep Power: 13	Car won't start brake pedal too stiff Tried starting my car this afternoon and when I pressed the brake pedal I noticed it was very stiff (never experienced this before) and the car won't start because the pedal doesn't go down far enough to engage the switch. What could this be? I checked the brake fluid level and its at the right amount, could it be a vacuum leak? How could I detect which line is causing the issue? Thanks guys!

08-08-2019, 10:10 PM	#3 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324198	The pedal is stiff because you have no vacuum. You won't have any vacuum until the engine starts. That doesn't mean you have a leak - still possible but low on my list - as, without the engine running, a press or two on the pedal will bleed off any stored vacuum. The pedal doesn't have to move very far (less than an inch) to change the state of the switch. The switch could be the problem but, as with a vacuum leak, it's low on my list. Get an OBD tool and see if any DTCs are present. Modern cars are pretty good diagnosticians. Edit: Try shaking the shifter while starting the engine. There is a Park/Neutral switch that can keep the engine from starting. danelonson and Optimiser like this. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma Last edited by SouthArk370Z; 08-08-2019 at 10:13 PM.

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08-08-2019, 08:58 PM	#2 (permalink)
danelonson Base Member Join Date: Apr 2012 Location: Florida Posts: 82 Drives: 12 370z 7AT Sport Rep Power: 13	Bump for help

08-09-2019, 02:04 AM	#4 (permalink)
danelonson Base Member Join Date: Apr 2012 Location: Florida Posts: 82 Drives: 12 370z 7AT Sport Rep Power: 13	Thank you SouthArk for your help. Do you think it could also be the check valve in the vacuum hose that's connected to the brake booster that is going bad?

09-12-2019, 11:06 PM	#6 (permalink)
AARONHL Base Member Join Date: Jul 2017 Location: Connecticut Posts: 50 Drives: 10g374dr6mt Rep Power: 8	Try engaging the switch with your hand while your start the car (maybe having a friend would help) And is your battery good? Are you sure you got enough power to start the car