Perhaps the check valve is bad that plugs into the booster
1976 - 1980 FJ40 Brake Booster Replacement List
- Thread starter Vae Victus
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Can someone enlighten me on the function of this check valve? When I got the rebuilt booster (sourced from PartsGeek), it did not come with a check valve, so I simply took the one from the old booster and plugged it into the new one. As I recall, it was just a plastic port that screws in. I didn't think much of it at the time. Is it still possible to buy a new one?
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fj401978
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It is a check valve for the vacuum, don't know its exact function, but yes, it is still available...
44730-22050 $24.42 at toyotapartszone.com. That's for the 'tandem' booster, the check valve for the single booster,
44730-22060, is NLA from Toyota.
44730-22050 $24.42 at toyotapartszone.com. That's for the 'tandem' booster, the check valve for the single booster,
44730-22060, is NLA from Toyota.
Thank you. As of this morning the booster doesn't provide assist anymore. The car still idles smoothly and drives fine, so I don't think I screwed anything up with the vacuum lines.
I'm thinking it shouldn't be doing that. Have you removed and plugged the vacuum hose to be certain it is the booster and not something else? Does it make the same sound with the engine off and you press the brake pedal?
When you press the pedal it opens a valve allowing air into one side of the booster diaphragm. The air comes in where the pedal push rod goes in. My booster has a foam plug there, I assume to keep out dust and limit air rushing noise. If the valve is partially plugged it might make that sound until the equalizes. I suspect you have a hole in the diaphragm, though. Is it still under warranty? I went though three boosters to get a good one. Two of the boosters would not return after pressing on the pedal. I had to pull the pedal back up with the top of my foot.
When you press the pedal it opens a valve allowing air into one side of the booster diaphragm. The air comes in where the pedal push rod goes in. My booster has a foam plug there, I assume to keep out dust and limit air rushing noise. If the valve is partially plugged it might make that sound until the equalizes. I suspect you have a hole in the diaphragm, though. Is it still under warranty? I went though three boosters to get a good one. Two of the boosters would not return after pressing on the pedal. I had to pull the pedal back up with the top of my foot.
With the engine running, when I press down on the brake pedal, I can hear a loud "whoosh" sound from around the booster rod within the cabin. If I step on the brake pedal with the engine off, I don't hear any such sound.
Really you went through 3 boosters? What brand is it? It's a pain to take the booster out and I'd really hate to repeat this exercise. Maybe these Centric rebuilds are junk.
PartsGeek says most parts have a 1 year warranty, so I'll have to check on that.
I've seen other sources that sell rebuilt boosters for $400+ (double of what Parts Geek charges for the Centric), but from the photos those look very much like the Centric booster.
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There were a slew of replies after I started drafting this message. I didn't see your response that your booster had completely failed.
I actually switched to a GM style dual diaphragm booster using my own firewall and master cylinder adapters. The first two were made by MBM purchased through speedway. My current booster is a 9" dual from SSBC. They go for under $150 making it an economical choice if you can do the fab work.
I actually switched to a GM style dual diaphragm booster using my own firewall and master cylinder adapters. The first two were made by MBM purchased through speedway. My current booster is a 9" dual from SSBC. They go for under $150 making it an economical choice if you can do the fab work.
I just ordered a new check valve, but it's looking like it won't solve the problem.
Unfortunately I can't fabricate, so my options are limited. The truck is also entirely stock, so I prefer to stay stock as well.
Unfortunately I can't fabricate, so my options are limited. The truck is also entirely stock, so I prefer to stay stock as well.
I believe the 'rebuilt' booster did not have new diaphrams in it and what you hear is vacuum rushing through a giant crack in one diaphram.
I don't understand why anyone would do anything other than grab a used minitruck or 4runner booster from a junk yard for $35 and be happy for many years. (or 60 or 80 series) Compatibility, great Toyota quality...
I don't understand why anyone would do anything other than grab a used minitruck or 4runner booster from a junk yard for $35 and be happy for many years. (or 60 or 80 series) Compatibility, great Toyota quality...
What is the tiny modification?
From what I can tell, it's not exactly easy to source a 60 series booster either. Where did you get yours?
In my opinion a 60 series booster fits best in a late 70s 40. I also used a 60 master. It looks like it was made for a 40, and takes up much less space. Just need to make a tiny modification to the booster before you install it.
I just got it off of a wrecked 60. You have to mount it upside down for the holes the line up. When you mount it upside down the little drain slot where the master bolts is now pointing up. So you have to take a cutting wheel and make a slot on the side now pointing down for fluid to leak down so it doesn't get into the booster if your master ever develops a rear seal leak.
Vae Victus
Posting more than I know
- Thread starter
- #73
No, it shouldn't be hissing. Does it lose pedal pressure when you hold it in?
Vae Victus
Posting more than I know
- Thread starter
- #74
White Stripe: I agree if you cannot find the OEM. Racer65 is talking about the OEM replacement. Not sure if you were referring to his post (which is just above yours), or if your post was generic to the overall thread.
Is it safe to use a single diaphragm booster on a FJ40 with front disk brakes? I know it works fine on drum brakes.
For example, has anyone tried using 44610-60030 on a 76-80?
Kind of surprised the FJ60 booster is thinner, given it's a much larger truck. I thought the reason for the dual diaphragm is to provide more vacuum assist.
For example, has anyone tried using 44610-60030 on a 76-80?
Kind of surprised the FJ60 booster is thinner, given it's a much larger truck. I thought the reason for the dual diaphragm is to provide more vacuum assist.
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Sorry one more question...
With that FJ60 booster, which does not protrude out as much as the original unit, did you need to bend the brake lines going to the master cylinder?
I used the 60 master as well. I had to bend the lines a little.
>>Booster Dewey (repair place in Oregon http://www.boosterdeweyexchange.com/) cannot get diaphrams anymore either. He is done with the 76-80 rebuilds unless someone starts making the diaphrams again.
Does anyone know if diaphragms is the only showstopper? I'm thinking I can probably make some diaphragms to solve that problem, but not sure if Booster Dewey also needs other parts.
Does anyone know if diaphragms is the only showstopper? I'm thinking I can probably make some diaphragms to solve that problem, but not sure if Booster Dewey also needs other parts.
It would be done through a booster supplier. It's not any harder to make these diaphragms than other booster diaphragms out there, but a sample will definitely be required. Here are the key questions I have:
1) Is there any variation among these dual diaphragm boosters? My understanding is that they are all identical
2) Besides the gear heads in this forum, how many people would actually want to buy the diaphragms, and send it to Booster Dewey to have it rebuilt? The total cost can really add up, including labor and shipping, not to say the downtime while the booster is out of the car.
The reason I'm asking about diaphragms is because the prospect of recreating the entire booster is looking rather slim. The booster is a bit of oddity. It's actually a hybrid product, based on a Bendix design that has been licensed to Toyota. The Japanese company that originally manufactured it, called Jidosha Kiki Co, I believe is now part of Bosch.
