Brake Booster Died

[PDXAccord79]

Hello everyone.

So my brake booster died yesterday. I hit the brakes and the pull from the vacuum almost killed the car. I pulled over, opened the hood and the booster hisses and causes the engine to die when I hit the pedal. I'm fairly sure that this is what's been causing the bouncy tac since the issue seemed to happened mostly when the car was stopped with brakes on.

So I'm going to replace the booster but it doesn't have a check valve on the hose. Does it need this? The car didn't have one when I initially took it apart. The only valve I can find is $38 on Honda Parts Now, otherwise the only thing I can find is this:

http://www.carparts.com/details/Honda/Accord/Adler/Brake_Booster_Check_Valve/1995/W0133-1642573.html

Will this work or should I just forget about the valve?

EDIT: Did some reading and the check valve keeps vacuum in the booster in case the engine goes out. My brakes have basically 100% failed when the engine goes out so I purchased the check valve from Honda Parts Now to hopefully prevent a rather scary situation from happening again. I've also read on this forum that the booster can cause the tac to bounce if the valve isn't there so that's another reason to add it in. Maybe it will also fix my weirdo high gear surge issues? We'll find out!

[2oodoor]

I see you got it, awesome.

[PDXAccord79]

How Stuff Works gave me that check valve explanation, surprisingly enough. I really hope the valve gives me at least some braking if the engine goes dead. I don't feel safe driving it now due to how hard the brakes fail if the engine dies.

[2ndGenGuy]

You should still have manual braking. It's a scary feeling though when the engine dies unexpectedly... You could disconnect the booster for now so you can drive it on just manual brakes, but if you've got a backup car, might as well. Manual brakes just require a bit more effort, but they aren't bad after you get used to it.

[2oodoor]

How Stuff Works gave me that check valve explanation, surprisingly enough. I really hope the valve gives me at least some braking if the engine goes dead. I don't feel safe driving it now due to how hard the brakes fail if the engine dies.

If the booster is bad it will leak out despite the check valve, all vac brake boosters have the check valve more for when the engine does quit, so.. You have a stalling problem? That is the concern now it sounds like.

[PDXAccord79]

When the ICM went out I went from normal brakes to hard, almost useless brakes at 70 MPH. This time when the vacuum leak almost killed the engine it caused the pedal to go stiff as well. I can't be driving this car if this is what it's going to do when the engine stops spinning. Honestly if the check valve doesn't at least give me some brakes when the engine goes out the car is getting sold. I can't trust a car that does this, especially not at freeway speeds.

Saying that the brakes "work" when the vacuum goes out is a lot like saying a rock "works" as a hammer. Will it hammer the nail? Eventually. Is this even remotely safe or reliable. No.

[lostforawhile]

When the ICM went out I went from normal brakes to hard, almost useless brakes at 70 MPH. This time when the vacuum leak almost killed the engine it caused the pedal to go stiff as well. I can't be driving this car if this is what it's going to do when the engine stops spinning. Honestly if the check valve doesn't at least give me some brakes when the engine goes out the car is getting sold. I can't trust a car that does this, especially not at freeway speeds.

Saying that the brakes "work" when the vacuum goes out is a lot like saying a rock "works" as a hammer. Will it hammer the nail? Eventually. Is this even remotely safe or reliable. No.

the brake booster on this car is just like the brake booster on any other car, getting rid of it means you will have to somehow find a modern car without power brakes, the same thing will happen on any car with power brakes. If you push on it hard enough the car will stop, there is still a mechanical connection between the pedal and the master, the booster diaphragm just helps move it. Have you checked the check valve? or the booster for leaks? the booster should retain some vacuum even if the hose failed.

[lostforawhile]

you didn't need to spend all that money on the check valve, you could have gotten one from any Honda or even ebay, I would have sent you one, I have several, it's not specific to any Honda or even a brand, if there is no check valve no wonder you have an issue

[PDXAccord79]

As long as I know this check valve will keep normal brakes if the engine stops running I'm fine. I had a 73 Beetle before this car. No power brakes and it stopped fine so power brakes is still very new to me. I'm fairly sure the moron that owned it before I took it apart removed the check valve and never put it back. There were other "interesting" modifications on this car before the rebuild.

EDIT: And yes, the booster is dead. Put my foot on the brake and it hisses and pulls the RPM down until the engine almost dies. New booster and valve is on the way.

[lostforawhile]

As long as I know this check valve will keep normal brakes if the engine stops running I'm fine. I had a 73 Beetle before this car. No power brakes and it stopped fine so power brakes is still very new to me. I'm fairly sure the moron that owned it before I took it apart removed the check valve and never put it back. There were other "interesting" modifications on this car before the rebuild.

EDIT: And yes, the booster is dead. Put my foot on the brake and it hisses and pulls the RPM down until the engine almost dies. New booster and valve is on the way.
That's a lot of money for the valve, I would have sent you one they are on ebay for ten bucks, and everywhere at the yard

[PDXAccord79]

I have an hour plus commute one-way on mass transit so I need this stuff ASAP. If it's an official Honda valve awesome. I don't have another car so if this one goes down I'm stuck on the bus. Also I've had enough problems with the brakes on this thing so far so no used parts. Sorry if I'm getting cranky but if this stuff doesn't make this car have reliable brakes someone will have the opportunity to purchase a vintage Accord.

[lostforawhile]

these brakes are just like a modern system, your booster simply wore out from being in use for so many years, plus someone removed the check valve, boosters and check valves are very reliable and dont fail very often, you need to make sure you adjust the free play at the pedal after you install the booster and master back together, if it's too tight, your brakes will start to slowly lock up, as the booster wont release all the vacuum, make sure you bench bleed the master first, and make sure it's not leaking fluid at the rear seal, that will destroy your new booster

[2ndGenGuy]

I honestly can't say that mine ever had a check valve in it either. I dunno if someone removed it or if there was just never one there. The vacuum lines looked like the original ones with the factory molded bends in them when I got it, so it's hard to say if someone removed it at some point, or if it was just never there... (Or if I forgot to put it back in when I swapped the carb.)

My booster went out a couple months ago (along with everything else at the same time lol), and I've been driving with manual brakes until I can get my other problems solved first. At least with the booster disconnected, and the vacuum line plugged, your engine will not stall out, and your pedal feel will be consistent. It will be perfectly safe, I can lock up the brakes no problem. It should drive pretty much just like your Beetle did at that point. It will get you by just fine until you get the new booster in.

I disconnected it for the same reason you described, where the engine would stall at idle, and the pedal would suddenly feel hard and useless, I think it's just that sudden transition from power to no power while driving that makes it scary. When you've got an old booster, and put new brakes on the car and give it a fresh bleed, I think it just works the booster diaphragm to a point where it hasn't been moved to in a while, and it cracks.

EDIT: I'm not trying to suggest that you run it w/o the booster forever. Just trying to give you a quick 5 minute fix that will get you to work and back w/o having to take the bus, at least until your new parts come in. Try it and run it around the block, you'll see what I mean and you'll get used to it really quick. :)

[PDXAccord79]

I would do this but my booster should be here tomorrow. No check valve since Honda Parts Now is now saying it's discontinued. I guess I'll see if I can find a universal or pull one off another car.

[2oodoor]

A check valve from anything works as long as it fits the hose and grommet.
If you can't stop the car wthout the booster I would check the rear brake adjustment and bleed all four corners and the master.
Don't get upset with us, just the 3 of us helping have probably 50 yrs experince all together.
2GGuy what how does the hose connect to your booster? Grommet or what? Usually the C V pushes in the grommet-the hose slides on the Cv other end so does yours have a nipple?

[PDXAccord79]

The brakes will work but the pedal gets really, really stiff and I have to apply a lot of pressure to slow it down. The brakes were great before the booster went out. I had one side that was pulling a bit at high speed but adjusting the rear drums took care of that. It also was doing a bit of the sticky caliper slide thing but that's gone away with use.

[2ndGenGuy]

Yeah, my booster has a nipple on it. The vacuum hose just slides on with a clamp on it. I recall seeing somewhere that the check valve is just in line with the vacuum hose, but it's been a while sine I've looked.

[2oodoor]

In that case not just any CValve will do, it has to have 2 hose nipples since itis inline.
PDX , you do know when brakes fail you have to pump them, just making sure because I watched somebody drive thru a garage door after driving for years didn't know to pump the pedal to get more pressre.

And, these powerstroke Fords you see driving around use a vaccum pump for the booster...they fail quite often so there is no power assist when that happens. It does make the vehicle almost undrivable because of the weight of the veh. They do still stop though. Like Lost said, there is still total hydro mechanical connection there but just takes effort to push.

[lostforawhile]

got your pm I'll get you a check valve on the way, it's a three g one but they are universal, you install it in the hose with the arrow pointing towards the intake manifold

[PDXAccord79]

Guess who's an idiot? This guy!

So I had a part that I thought was an inline fuel filter because it went to the carb. It's a little metal barrel with posts looking thing with the letters ENG on it and an arrow. I went and looked at my pics before the rebuild and it's no filter. Looks like I'm the dumbass that forgot to reinstall the check valve when I put the car back together. It's sitting in my box of crap right now so I have the piece. When you only have yourself to get mad at it makes it that much worse...

So I'll install that guy along with the new booster tomorrow when I get off work and everything should be ready to go. Lostforawhile thank you for the offer. If this thing doesn't work tomorrow you'll be getting a PM from me.

[lostforawhile]

Guess who's an idiot? This guy!

So I had a part that I thought was an inline fuel filter because it went to the carb. It's a little metal barrel with posts looking thing with the letters ENG on it and an arrow. I went and looked at my pics before the rebuild and it's no filter. Looks like I'm the dumbass that forgot to reinstall the check valve when I put the car back together. It's sitting in my box of crap right now so I have the piece. When you only have yourself to get mad at it makes it that much worse...

So I'll install that guy along with the new booster tomorrow when I get off work and everything should be ready to go. Lostforawhile thank you for the offer. If this thing doesn't work tomorrow you'll be getting a PM from me.
lol

[PDXAccord79]

Alright that brake booster fixed a number of issues. There's no chatter or drop in RPM's when I'm in reverse or starting in 1st, the idle is smooth and the surge at 65 is gone. Throttle response in general is much better. The brakes also now feel like modern brakes. Fixed it!

[lostforawhile]

Alright that brake booster fixed a number of issues. There's no chatter or drop in RPM's when I'm in reverse or starting in 1st, the idle is smooth and the surge at 65 is gone. Throttle response in general is much better. The brakes also now feel like modern brakes. Fixed it!
did you have to reset the pedal free play?

[PDXAccord79]

The pedal is 7.25 inches from the floor and has about an inch of free play before I feel it hit the master cylinder. The pistons in the boosters were set at the exact same length so I didn't mess with those. I drove it and got everything nice and hot yesterday and the brakes felt great the whole time. No fading or loss of power (I've had brakes lock up in the Bug due to a tight adjustment so I know what to feel for). The car will now lock all 4 wheels at 50 mph with far less effort than I was expecting but can still provide smooth braking with normal pedal use. Add the acceleration and surging fixes and it almost feels like a different car.

It does now run a little rough with the headlights on but I'm thinking the carb now needs to be readjusted due to the change in vacuum. Easy enough.

[2ndGenGuy]

Awesome man! I'm glad you got her up and running like a champ!

[PDXAccord79]

Thanks. Did you ever figure your issue out?

[2ndGenGuy]

Not yet. I'm going to dig into it more this afternoon. I tore apart my whole ignition harness that I built, and I can't see anything wrong.