Brakes Hard as a Rock

[KingSwingles]

So I've had this issue previously in my 3rd gen 4Runner, which lead me to do some brake work. I put on steel braided hoses on the front, and upgraded my booster and master cylinder to a T100. Didn't have any issues until today I was going home in some snow and hard brake pedal and no stopping. When I last bled my brake lines, there was no air pockets.

I hope it doesn't come back but I'm tired of fearing my truck won't stop when I need it to

 

[19963.4lsr5]

First thing I'd replace it the vacuum check valve. Been there before.


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[tjansen]

Check valve now $95 Mobile Al. Toyo dealer. Did not fix mine. Still looking. I do have a check valve that is closed out and almost closed in. Tiney little thing for $92 at same dealer. Not buying yet.

 

[GhostRing]

Check valve now $95 Mobile Al. Toyo dealer. Did not fix mine. Still looking. I do have a check valve that is closed out and almost closed in. Tiny little thing for $92 at same dealer. Not buying yet.

If it is the same part # at beginning of thread, I see prices averaging
about $45ish. Several parts.toyota.com type sites have free shipping
at $75, so maybe a few more bit & pieces to make it worth it?

 

[lbhsbz]

Check valve takes 5 seconds to test...try to blow through it both ways. Rare to see one of these fail.

There was a recall when I worked for the dealer back in 2000 or 2001 on the toyota echo (maybe prius?...can't remember) where we were replacing boosters for a similar problem, except in this case, water was somehow getting in the boosters and would freeze, causing no booster function until it thawed or was broken up after a couple pedal applications I guess. We never saw any of the symptoms out here in so cal, but we had to change 'em anyway.

If it's happening every morning...you might consider pointing a hairdryer at the bottom of the booster for a few minutes before startup to see what happens.

 

[Drcoffee]

The booster vacuum valve ices up in cold weather. Remove it and soak it in WD40. Reinstall it. That fixed mine.

WD40 stands for water displacement. It will not harm rubber either.

 

[tjansen]

Replaced Vacuum booster.

Replacing Vacuum booster with one from Auto Zone. Hose also. Works good but different.

 

[Crobalex]

Hey new guy here just trying to get posts in so it will let me start a discussion. I’ve had issues like this in the past and it’s usually the vacume booster

 

[Bad Luck]

Hey new guy here just trying to get posts in so it will let me start a discussion. I’ve had issues like this in the past and it’s usually the vacume booster

Welcome to the forum. If you have a question you can ask here until you get enough posts to start a thread if your question isn't answered: The 3rd Gen All Questions Allowed Thread
Here's a 3rd gen specific search to help you look for the answers to your problem: https://www.google.com/search?q=sit....69i57j69i58j69i59l3&sourceid=chrome&ie=UTF-8

PLEASE DO NOT SPAM RANDOM THREADS TO GET YOUR POST COUNT UP