You can do nothing. But, the vacuum line TO the booster, block it off. It will quit the hissing and the booster will be not in the system. Up to you.
Snake in my booster...hisssss! Video (1 Viewer)
- Thread starter sproggy
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You can do nothing. But, the vacuum line TO the booster, block it off. It will quit the hissing and the booster will be not in the system. Up to you.
- Thread starter
- #22
I might try that just to understand what my booster is doing/not doing.
What probably is happening is this; The intake manifold has VACUUM when engine is running. So, VACUUM line to the booster creates a large pressure and there is a rubber diaphragm in the booster. Well, rubber ages and cracks so when you go to push the pedal and flex it, there is a leak and that is probably it.
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- #24
thanks. I'm wondering specifically why it stops hissing when I nudge the pedal in about 1/4 inch. I guess I'm somehow sealing up, more or less, the leak.
Exactly, a big diaphragm flexes and it is leaking and sealing during flex actions. I had this happen to me and after a rebuild , all was fine. ALSO, A GOOD HINT IS WHEN YOU INSTALL THE REBUILT UNIT, IN THE VACUUM LINE INSTALL A FILTER. REASON, FUEL FUMES FIND THIER WAY INTO THE BOOSTER, ACCELERATING THE RUBBER TO DEGRADE.
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- #26
Whoa that's wacky. Which way is the flow of the fuel filter? I guess arrow toward the booster. Is the filter going to filter out gas fumes? I wouldn't think it would do a great job on fumes since it is made for filtering a liquid. Might it restrict the power of the vacuum? Thanks for the pic!
Are there any rebuild kits still available? It's a pretty simple mechanical device. Not sure why they go for $500 on SOR. That's for a whole new one, mind you but still. Am I missing something? It's not like it's complicated like a carb....
I would recommend professional rebuild. Opening the booster can really hurt you. Stupid to try. Filters are not only for liquids. Do you have an air filter ?? Same concept.
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- #28
Well 71FFj40 did post this link early in the thread: Booster Dewey Power Brake Booster Exchange Inc.
I have to count my pennies and see how I want to spend them. I did check the price of a 4runner booster on Rock Auto. Still around $200. Oh well, not a huge expense. But it's always on top of the myriad other expenses. In these old junk runners like mine (I say that with affection), the failing parts list never ends.
I have to count my pennies and see how I want to spend them. I did check the price of a 4runner booster on Rock Auto. Still around $200. Oh well, not a huge expense. But it's always on top of the myriad other expenses. In these old junk runners like mine (I say that with affection), the failing parts list never ends.
thebigredrocker
SILVER Star
What about a pick-n-pull booster like mace recommended? Looks like they are $30.99.
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- #30
Hmm I never knew Picknpull was a chain or even a store. I just thought people meant the local junk yard when they mentioned pick n pull. My thoughts on the booster from a picknpull is that the rubber in them might be just as shot as the one in my fj40....don't you think? and also might need a rebuild. I wouldn't imagine there's a guarantee.
Check the gasket where the hose is attached to the booster.
The rubber could be rotted or hardened so it does not get a good seal.
The rubber could be rotted or hardened so it does not get a good seal.
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- #33
I will check that, thanks!
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- #34
In the end, I decided to get a new booster from City Racer which I just ordered today. Costs more than a used mini-booster from the boneyard but this one is new and should be a perfect fit. I felt the extra money was worth the peace of mind, sure fit, and no hassle.
How much can I drive before burning out those valves? Would it happen in a week driving 10 miles a day?
How much can I drive before burning out those valves? Would it happen in a week driving 10 miles a day?
