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87 GL Wagon Brake Booster Stud Broken


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Busted the stud off the the brake booster while installing the master cylinder, there's enough to grip it and take it off but i haven't had any luck yet getting a good grip. 

 

What I'd like to find out is if I can tap out the old stud if I can't get that one removed, I just have no idea how much metal there is there.

 

My book doesn't have rebuild instructions for the booster because "it takes specialized tools" it says, so I don't have an exploded view or any other reference. I have zero experience with brake boosters (or master cylinders for that matter, but the book walked me through that.)

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What the book didn't say was "Hey dumbo, don't over torque it!"  I thought there was a seal between, which there clearly isn't because there is no gasket.  I come to realize this 3 drinks after the fact.

Edited by noahkort
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I think i might just JB weld the master cylinder onto the booster, then when the booster (or cylinder) needs to be replaced, I'll replace both. Am I crazy?

 

I could drill out the stud, but after breaking stuff once I'm leary.  To drill it out, I'd have to take out the booster, or remove tons of stuff from the car, or get a really small drill. If I remove the booster and/or get a new one to install, according to my book I need 2 seals, one on either side of the spacer. I have not been able to find these seals on rock auto or the such any tips, reckon I could make them, but what am I sealing? Vacuum I assume?

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i wouldn't remove the booster, way too much work IMO, but too each his own.

 

if it's a stud - can you simple remove it and replace it?  if there's any metal yet - place a nut on the existing threads and weld them together.  then use a socket on the nut to pull the stud out. 

*** again - i'm not sure if it's a stud or removable though i've never played with a booster before but someone will know or find a used one to look at...someone on here has one (or 3).  i do but not where i am now.

 

if that doesn't work out - i would drill and tap the existing stud/bolt as it sits.  drill right through the center of it and tap it for a very small high grade steel/fine thread bolt. 

i've done it before, just not on boosters.  not sure how deep can you go but you'll be threading steel into steel and don't need to torque it a ton so shouldn't have to go too far.

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If it's like the majority of boosters, it's not a stud. It's a bolt with a splined shoulder that is pressed in from the inside during assembly and then staked as well. There isn't enough material there to drill and tap. The new stud will tear out. Likewise for the JB approach. Your two ideas are tantamount to suicide. This is a huge safety issue. WHEN either idea fails, you will have reduced (if any) braking, most likely resulting in an accident. The only way I can stress how bad an idea either is, is by being rude, which I won't. Go to a PnP and get one or have someone here send you one.

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thanks for your input. The only thing stopping me from getting a new booster right now it is i haven't been able to find new seals. I can get a new booster on Rockauto.com for about 100. I spent 1000 on the tranny replacement between parts and labor so 100 to get the car back on the road is no biggie, my only concern is the seals, which I haven't found yet.

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used?  booster failure is so rare in Subaru's it's almost not worth buying new...i mean $100 isn't bad like you said but you'd also get whatever hardware there is...spacer, gasket, etc. 

 

like he said - i can't picture a seal either but i've only ever removed one out of a parts car....

 

i'd still try to avoid replacement....weld a piece of steel over the the mounting bracket somehow.....LOL

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on my buggy i have a 02 impreza booster on the 1rst gen body the 4 mount bolts are generic and master bolt up is same the only mod was the length of the rod to pedal and some clearance to body if your going to change it may as well upgrade it to biger one

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