Sudden Brake Issue

[98Gate]

A little backstory. I had someone almost hit me this past weekend, I had to lay on the brakes about as hard as possible. ABS engaged, came to a stop, close call but car and all folks are safe. Fast forward to next morning. Brake pedal is stiff as can be when I put my foot on the brake to put it into gear. I push on the pedal hard and it seems to go back to normal. Well now driving it today, the pedal is randomly going stiff on me out on the road. Dangerous and I need to get this thing diagnosed. What do yall think the cause could be? It feels like my brake booster is bad, there is pressure from the master cylinder. When the pedal is firm, it will still engage the brakes but just with a ton of force involved. No ABS light so I would assume the ABS motor is okay. Any thoughts? Any reasonable tests to isolate this issue?

-98Gate

 

[T4R2014]

Check your booster vacuum hose. I guess fluid level at the same time. To test the booster you pump the pedal without the engine running until it's stiff. Keep holding it and start the engine and it should sink. If not it's bad, at least that's how I verified all my bad boosters. This is a OEM or Seiken only part, if that's too rich for you just get one at a junkyard. Aftermarket and reman is junk but feel free to experiment with a major safety feature if you disagree. I recommend you throw in a new master cylinder if you are going in there.

 

[98Gate]

Check your booster vacuum hose. I guess fluid level at the same time. To test the booster you pump the pedal without the engine running until it's stiff. Keep holding it and start the engine and it should sink. If not it's bad, at least that's how I verified all my bad boosters. This is a OEM or Seiken only part, if that's too rich for you just get one at a junkyard. Aftermarket and reman is junk but feel free to experiment with a major safety feature if you disagree. I recommend you throw in a new master cylinder if you are going in there.

It has been so intermittent, when I start the truck sometimes the pedal will stay stiff on startup, sometimes it will go down as normal. I dont mind ponying up for the investment, quality parts are worth it. Would the check valve be something to check?

 

[T4R2014]

It has been so intermittent, when I start the truck sometimes the pedal will stay stiff on startup, sometimes it will go down as normal. I dont mind ponying up for the investment, quality parts are worth it. Would the check valve be something to check?

Definitely worth checking for blockage, but still sounds like a bad booster to me.

 

[98Gate]

Definitely worth checking for blockage, but still sounds like a bad booster to me.

I think so too, I think its on its way out and I dont want to be pissing in the wind when it croaks. Thank you for the help and pray for my bank account haha

 

[T4R2014]

I think so too, I think its on its way out and I dont want to be pissing in the wind when it croaks. Thank you for the help and pray for my bank account haha

Feel better knowing there's people paying over $400 a month for a Nissan with a CVT.

 

[JohnMc]

I had the check valve get sticky on mine. Mostly in cold weather, but symptoms were that the brake pedal would be very stiff, very little braking when you pressed the pedal, you had to MASH it. In my case when it warmed up under the hood it worked fine again. Check valve is cheap and easy to swap.

 

[3bears]

I had the check valve get sticky on mine. Mostly in cold weather, but symptoms were that the brake pedal would be very stiff, very little braking when you pressed the pedal, you had to MASH it. In my case when it warmed up under the hood it worked fine again. Check valve is cheap and easy to swap.[/QUOTE

agree ive had the check valve go bad on me too with same symptoms. You can pull it, spray with wd 40 or whatever, rattle it around and blow air in it for a temporary fix,