Brake pedal to the floor

[Makaio]

This happened only once today for about 2 blocks. I press on the pedal and it goes to the floor and the dash mounted brake light comes on momentarily. After a few seconds of driving, the pedal gets hard and it never happened again. I changed the master cylinder about a month ago so I cautiously ruled that out. I changed the front pads BUT never resurfaced the slightly ground rotors. Could this incident be simply the pads seating? It's rock hard when I stop now and the there are no fluid leaks. Thanks for any thoughts or suggestions.



Aloha,

Matt

 

[MMeier]

Possible brake booster on its way out?

 

[Makaio]

Mark,



If the booster was going South, wouldn't the pedal be hard? The symptom is like a bad master cylinder but it's brand new; about a month old. I tried calling NAPA to inquire about a warranty but they close early on Saturdays. There are no visible leaks and the fluid level is full. My booster runs off the power steering pump. You have any idea how I can check that? Thanks for your input.



Aloha,

Matt

 

[JLEONARD]

Could this incident be simply the pads seating

No

Sounds like a master cylinder problem. Just because it's new doesn't mean it's good. I'd return it.

 

[Makaio]

Jay,



That's what kept popping up in the back of head while I was trying to figure out what could it possibly be. I kept saying to myself, "It's brand new, it can't be the master. Then again, it just might be". It was new from NAPA and made in Italy. Good thing I still have the receipt. Oo.



Aloha,

Matt

 

[MMeier]

When mine was acting up last year, one time the pedal wouild be hard, toward the top, next time it would be on the floor. So I plumbed in a vacuum gauge onto the spare nipple by the booster connection Would have 25-27 " of vacuum, step on the whoa pedal, went down to 0 right now, several times. I replaced both as a unit, since it was only like $30 more for the combo vs. just buying the master. So I may have had both gone bad, seeing as they were original units, and i plan on keeping this one around for quite a while, I went and replaced both.

 

[Makaio]

$30 more for a complete unit? I must have looked at a wrong part online. One Mopar site showed $400 some odd dollars for just the booster. I bought a new master from NAPA for $120 or so I'm thinking it should be around $150 for master and booster? Anyhow, my booster is plumped off the power steering pump. If the booster went South, wouldn't I have lost power steering too?

 

[MMeier]

Matt, you are on a vacuum system, correct? Not hydroboost? The vacuum pump is "attached" to the PS pump, they are seperate items. Like I said, hook up a vacuum gauge up by the booster connection and see what you have for vacuum, then step on the brake pedal and see what the gauge does.

 

[Makaio]

Mark, I gotta take a good look at it in the morning. Everyone is telling me it's a hydraulic booster that works off the power steering. Did our trucks come with vacuum and hydro? I don't have an FSM so I have no clue of the available variations.