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01 Gen2 Brake booster failure after overhauling calipers?

459 Views 3 Replies 2 Participants Last post by  Rav4Wrencher
So I've had some problems with my brakes I've been overlooking since they worked fine, but I decided to break the calipers down and paint them with some vht and replace the seals. Job took a few days and the front lines bled dry. I rebuilt everything, (Caliper piston boot retainer wasn't on either caliper or in the kits, listed on manual diagram tho?), bled just the front from inexperience and had my usual feeling brakes for a very little bit but then my pedal keeps going down all the way to the floor and is slow to return and remains spongy even with pumping. I have since flushed the system, replaced the 2 bleeders I wire wheeled, and fully bled the master cylinder and all the corners.
Running the car 2 minutes, depressing my foot to the floor, shutting off the engine, I can hold the pedal down 30 sec.
With engine off I can pump brakes and it's rock hard at 3 different levels for the 3 pumps until you reach the top of the pedal which is solid, minus about half an inch of play at the top.
Pedal slowly sinks to floor and slow to rebuild pressure still after flush and bleed
My guess from looking stuff up online is a check valve or line? I looked for a valve along the line but lose where the line goes behind the passenger side of the engine, but I can't find evidence of there being a check valve in the manual? Is it built into the booster? Where should I go from here? This testing was done on stands and without revving the engine at all too, would that affect results? Thanks in advance
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did you pressure bleed the system? the other thing to check is take off the vac line to the servo and put a bit of rag or cotton on some stiff wire and feed it from the vac line grommet to bottom of the servo and see if any fluid is in there also do you get fluid loss?
 

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Discussion Starter · #3 ·
did you pressure bleed the system? the other thing to check is take off the vac line to the servo and put a bit of rag or cotton on some stiff wire and feed it from the vac line grommet to bottom of the servo and see if any fluid is in there also do you get fluid loss?
I bled the system with a simple one person bleeder with just a tube in a bottle with fluid in it. That's what my manual said to use. What do you mean by servo? The booster itself? I haven't touched the vacuum system yet, the only testing for the booster I've done is what's listed above but I'm not losing fluid, with the car off I can hold pressure just fine, It's only acting funny when running by, the pedal slowly sinking to the floor, (I see people say it's normal but I haven't felt it like that before), and very slow to build the pressure back. Like I said all the testing has been on jacks so I'm thinking of driving it a tiny bit to see if putting the system in use will fix it or more likely reveal the problem. I live in a rural area and I'm certain I can have some brakes so I should be good. Can I remove the brake booster check valve without messing up the system? It's built into the booster so idk lol
 

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Discussion Starter · #4 ·
did you pressure bleed the system? the other thing to check is take off the vac line to the servo and put a bit of rag or cotton on some stiff wire and feed it from the vac line grommet to bottom of the servo and see if any fluid is in there also do you get fluid loss?
Turns out I'm an idiot, my brakes work. It started with a bad braking distance then tightened back up like I had to rebed the brakes. Thanks anyway lol
 
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