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Oooops Brake servo

Well, all the advice I still go and cross thread a bolt but not the way I thought I would if I was going to do it .

Basically the bolt was in quite a few threads until there was a fair bit of resistant and didn’t go easy to turn again. I didn’t think it was cross threaded as if it was it would started from the beginning of the thread so me being me decided to use the ratchet and go all the way down . Realising at the moment in time I cross threaded the bolt as took it out and halfway down the female bolt and male bolt the threads were striped .

I don’t understand how it cross threaded as it went in without no ease i would say about 6-8 turns before it was resisting and it went in straight so can anyone explain to me what caused this to happen as prev said was not expecting it :frowning:

Assuming this post and your previous are not fiction it is apparent that you have no idea what you are doing. You will have to have a mechanic fix this for you and the next time you try something see if you can find a friend or relative to at least watch you.

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Don’t have to get angry about it keep your hair on, only asking a question , isen’t this what this forum is for I guess not.

Angry? What was angry in the reply? Your post indicates a total lack of mechanical insight and tallent so you would be wise to seek professional help.


The reply wasn’t angry, but this is a teaching forum. Newbies screw up, and I don’t think there’s any such thing as natural talent when it comes to auto repair. We’re not playing the cello here, we’re wrenching on machinery. I firmly believe that anyone can do the actual mechanical labor if they’re smart enough to follow directions - it’s the diagnostics that takes talent - the rest can be taught to anyone.

OP, perhaps the threads were already damaged before you got to them.

I’m not so sure what’s the big deal. I’m sure this has happened to most of us at one time and one form or another. Usually can be fixed with a helicoil, as long as there is sufficient access to the bolt hole, it’s not that difficult.

This can happen if the inserting fastener has a defect in the threads part way up the shaft. It goes in smooth at first but then hits the damaged section and the rest is history…

Or could it be a metric/SAE mismatch?

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Thankyou that is all I wanted to know appreciate the help to the people who gave it to me and it now all working again , the diaphram inside the brake servo was fault it was split which correct me if Im wrong wasent allowing a vaccum, as this resulted in me really having to press down on my brake pedal.

It just it didn’t make sense how it could happen if the bolt was going in a good amount of turns and straight so what your saying is it normally, a person before has damaged the thread, a bolt or the internal threads has been damaged in someway causing it to disloge, or wrong bolt or thread that bit Im unsure about

Vacuum brake boosters generally have studs and nuts, where is the bolt that gave you difficulty?

I think most of us have learned this lesson the hard way. I have. If unusual resistance is encountered remove the bolt and closely inspect it for damage. If damage is slight chasing the threads with a proper die may solve the problem if damage is major take the bolt with you and buy a replacement. if the new bolt encounters the same resistance the female threads are damaged and it is probably helicoil time. It aint’ “Rocket Surgery”.

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The key is to stop immediately and back off. This is something that one has to learn the hard way it seems. It’s no different when cutting new threads. Taps exact a stinging revenge against those that do not heed the warning signs :smile:

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