[atariguy]

I'm assuming this has something to do with temperature, because it's a recent thing, but I won't really know until we get above freezing in the mornings again here in Utah.

When I first start up my '96 4WD SR5, the brakes don't respond initially (ie: when backing out of the driveway) unless I first pump them a couple times before taking it out of Park. I can also hear a hissing sound associated with pushing on the pedal when I've first gotten the truck started.

Is this because it's only 17 degrees outside, or is that a coincidence and I've got something going on that's potentially dangerous and needs to get fixed before it gets worse? I have had the truck for over 20 years, and I don't remember really noticing it before, so maybe that answers the question...

 

[BamZipPow]

It's probably yer brake booster. I had that issue about 5 years ago and ended up gitting a used one. I should've gotten a new one instead. The OEM version is discontinued (about $1400) and the aftermarket ones range from about $80 to $500.

Hard brake pedal...

Symptoms of my hard brake pedal. Whooshing sound heard from near the brake pedal when stepping on the brake pedal. I suspect a bad brake booster in particular the atmospheric release valve which is internal to the brake booster and is not serviceable without disassembling the brake booster...

www.toyotanation.com

Here's one off of eBay.

Power Brake Booster Fits 95-01 Toyota Tacoma T100 2.4L I4 | eBay

Toyota T100 1994 2.7L 2694CC l4 GAS DOHC Naturally Aspirated. Toyota T100 1995 2.7L 2694CC l4 GAS DOHC Naturally Aspirated. Toyota T100 1995 3.4L 3378CC V6 GAS DOHC Naturally Aspirated. Toyota T100 1996 2.7L 2694CC l4 GAS DOHC Naturally Aspirated.

www.ebay.com

 

[swampedout]

Just dont buy one from autozone!
Should be an easy job.

 

[TXRailroads73]

Jumping in on this one... same deal, only when it's super cold out, my brake light on dash comes on, start up truck, let it warm up, after my first brake when backing out or stop sign ONLY WHEN IT'S COLD OUT, spring, summer, no light

 

[BamZipPow]

Jumping in on this one... same deal, only when it's super cold out, my brake light on dash comes on, start up truck, let it warm up, after my first brake when backing out or stop sign ONLY WHEN IT'S COLD OUT, spring, summer, no light

I would still say the brake power booster. I just replaced mine and I don't have those issues any more.

 

[TXRailroads73]

I would still say the brake power booster. I just replaced mine and I don't have those issues any more.

Where would recommend one?

 

[BamZipPow]

Where would recommend one?

This is the one I got off of eBay. It showed up in about 3 days.

Power Brake Booster Fits 95-01 Toyota Tacoma T100 2.4L I4 | eBay

Toyota T100 1994 2.7L 2694CC l4 GAS DOHC Naturally Aspirated. Toyota T100 1995 2.7L 2694CC l4 GAS DOHC Naturally Aspirated. Toyota T100 1995 3.4L 3378CC V6 GAS DOHC Naturally Aspirated. Toyota T100 1996 2.7L 2694CC l4 GAS DOHC Naturally Aspirated.

www.ebay.com

 

[atariguy]

I read your post about hard braking. My brakes haven't been hard - when they haven't worked right after starting, they've actually been really soft. Would it still be the booster? And I noticed today that I get the hissing any time they're used until the truck warms up. It was about 20 degrees this morning.

 

[96Wolf]

If you brake light is on, then likely your brake fluid is a little bit low.

Depending on what exactly is your symptom, when you say you have no brakes and you have to pump them, if that means you peddle goes to the floor then you have air in your hydraulic system. If the pedal is hard then it could be your booster, but you could also have a vacuum leak or restriction there.

 

[atariguy]

After observing some more, it seems that it's mostly just the hissing noise that's going on. There have only been a couple times when I've used them right after starting the truck when they haven't worked at first. The brake light is not on, brake fluid level is fine. I don't have problems with hard braking. So I guess I'll check for a vacuum leak tomorrow.

 

[BamZipPow]

Jumping in on this one... same deal, only when it's super cold out, my brake light on dash comes on, start up truck, let it warm up, after my first brake when backing out or stop sign ONLY WHEN IT'S COLD OUT, spring, summer, no light

Ooops! I just reread yer response.

Sounds like yer fluid level is low but that's just a possible indication that yer pads are wearing down to the point that you need to inspect them. You can always top the level off as well. But definitely take the time to inspect the pads.

 

[TXRailroads73]

Ooops! I just reread yer response.

Sounds like yer fluid level is low but that's just a possible indication that yer pads are wearing down to the point that you need to inspect them. You can always top the level off as well. But definitely take the time to inspect the pads.

Front pads, rear shoes replaced one week ago, fluid is filled but would like to change to new fluid, rear cylinders and front calipers are next in line

 

[atariguy]

Today was warmer (around 50 F). I checked the one vacuum hose I could see coming from the brake booster, it seems fine. I can only hear the hissing in the cabin, but I can hear it. Like I said, I haven't actually had any braking problems, except a couple times after first starting, when it was really cold. Just a hissing noise that comes and goes when pressing down the brake pedal. I made a video of it.

 

[BamZipPow]

Yup...bad booster. It will let go on you at the most unappropriate time. It may not be giving you a hard pedal yet...but it will do it. Brake boosters don't git better over time.

 

[atariguy]

Alright, I went ahead and ordered one from Ebay last night, along with the gaskets you mentioned in your other post. Hopefully it will all get here by Saturday. I'm not a mechanic, but I've done things like changing the disc brakes and the spark plugs. It looks like it won't be much more complicated than that. (Fingers crossed. )

 

[atariguy]

Well, the part arrived damaged. I'm trying to get it returned/refunded. But I've noticed that the prices have gone up since ordering it. And I also left a message in the other thread because I'm a little confused about the part # as I'm trying to search for the best deal.