Brake Booster Going South? (1 Viewer)

Tachycardic

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Two days ago, I noticed that when I start up the LC, the brake pedal is rock hard and the brakes are very weak. After the truck has warmed up for a minute or two, the brake feel and power go back to normal. Fluid levels are good. Brake booster failing? Thanks.
 

roadstr6

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Most likely the booster, yes. It starts out as an intermittent hard pedal and gets more frequent over the next few days. Ultimately, you will be afraid to drive it in traffic not knowing if you'll have good brakes or terrible brakes when you hit the pedal. I was always able to stop, even without the booster, but not knowing from one press of the pedal to the next how much pressure I needed to apply forced my decision to replace mine.
 

davidp14

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sometimes it just the check valve, which is cheap and easy to fix. try that first. Most times though, its the booster which is neither cheap or easy.
Mine was bad for a while before it replaced it. It got to where I could usually predict it. The loss of "boost" usually happens after multiple pedal presses without enough time for the booster to return to normal capacity. choose your brake pedal presses wisely.

If/when you replace, get a friend to help. This really makes the job easier. There's lots of threads on R/R brake boosters. My build thread has a couple pics and a tip or two I think.

Good luck
 

Tachycardic

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Thanks guys. With the engine warmed up, the brakes work consistently as they should no issue with pedal pressure or with braking power. It only happens when the engine is cold and at start up, but goes away quickly. Maybe I should just let the cruiser warm up a bit before driving off...

Thanks for the otramm video. The booster looks to be about $300? 80 Series, NEW OEM Seiken Brake Booster and OEM Gasket, 44610-60792

Alternatively, I was thinking about installing this: 80 Series 1FZ Brake Vacuum kit
Maybe I should do both? I don't know...
 
Joined
Oct 5, 2014
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Yokosuka
The check valve and grommet come installed on the Seiken booster. So you'd only need to replace the hose if you choose to go that route.

Id buy the booster first and install with your current hose. Test the waters and then go from there.
 

jjdeneen918

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Good time to upgrade to hydraulic assist booster. If your replacing, you might as well upgrade.
I have a build thread currently on going to hydraulic right now.

you could go all out & plan on the @WitsEndlarger brake rotor kit that is being discussed & designed at the moment too
 
Joined
Dec 10, 2007
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7,653
Yeah, don't ignore it. Years ago I ignored the symptoms of a failing master cylinder, until I struck the vehicle in front of me at a traffic light.
 

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