flyingbrick Posted November 9, 2015 Share Posted November 9, 2015 Hello. As per title, am upgrading booster and master to a later model and I need to shorten the input rod. I did this recently for a friend (drilled and tapped input rod, screwed in high tensile threaded rod to suit his cars brake pedal clevis) but my vehicle doesn't use a clevis. I basically need to cut a segment out of what's there and make it once piece again. So far I think my options are: -V both pieces heavily and tig together (Issues with heat affecting the metal?) -machine up a tight fitting sleeve and weld in place round each end of sleeve (heat again) -machine up sleeve and drill through sleve and components then pin in place with smaller high tensile bolts (which will have a shear rating MANY times higher than what my foot could dish out) Or (perhaps the most tidy) cut the shaft off to correct overall length, heat red hot, press flat, file then drill so that it looks factory (heat affecting the metal obviously) What would you guys do? Which options would be legal? I'd be happy driving a car with any of them done (done well) Quote Link to comment Share on other sites More sharing options...
Rookie Posted November 9, 2015 Share Posted November 9, 2015 I would cut it to length and thread both ends, and make up a threaded sleeve that joins the two together, that way you dont need heat. Alternatively, welding a sleeve over the top of the joint would be my next option. 2 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 9, 2015 Author Share Posted November 9, 2015 Great idea rookie. One of the issues is that the input rod doesn't come out of the booster. It makes simple jobs (like doing my mates booster) a wee bit harder (had to make a fixture to hold booster over the side of drill press bed) I might measure up tomorrow and see which size die goes over it nicely! Quote Link to comment Share on other sites More sharing options...
yetchh Posted November 9, 2015 Share Posted November 9, 2015 can't imagine too much stress on it, Ive cut and welded them before with no probs Quote Link to comment Share on other sites More sharing options...
Threeonthetree Posted November 9, 2015 Share Posted November 9, 2015 Edit: Just re read the first post and answered my own question Quote Link to comment Share on other sites More sharing options...
cletus Posted November 10, 2015 Share Posted November 10, 2015 from a cert point of view, it is not legal to weld a brake push rod 2 Quote Link to comment Share on other sites More sharing options...
cletus Posted November 10, 2015 Share Posted November 10, 2015 could you cut it, thread it and put a heim joint on it, then bolt that to the pedal? 3 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 10, 2015 Author Share Posted November 10, 2015 Thanks clint. It's 1/2" so will use a die and sleeve it Quote Link to comment Share on other sites More sharing options...
sr2 Posted November 12, 2015 Share Posted November 12, 2015 from a cert point of view, it is not legal to weld a brake push rod Most Hydrovac input rods are welded by the OE manufactures at the clevis/pedal end. Surely it's acceptable to duplicate the process when shortening? Quote Link to comment Share on other sites More sharing options...
Valiant Posted November 12, 2015 Share Posted November 12, 2015 could you cut it, thread it and put a heim joint on it, then bolt that to the pedal? I've done this a couple of times, works well. Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 12, 2015 Author Share Posted November 12, 2015 The heim joint idea is a good one....hmmm Quote Link to comment Share on other sites More sharing options...
cletus Posted November 12, 2015 Share Posted November 12, 2015 Most Hydrovac input rods are welded by the OE manufactures at the clevis/pedal end. Surely it's acceptable to duplicate the process when shortening?There are many situations where oe manufacturers weld things like castings, steering shafts etc. When it is an oe unmodified part it can be used, but there are some things that can't be modified by welding because of the risks involved if it goes wrong Quote Link to comment Share on other sites More sharing options...
yetchh Posted November 13, 2015 Share Posted November 13, 2015 I guess if you look at it from the ltsa's point of veiw, yes there are instances where oem stuff is welded, the factory would be accountable, but if they decide to let people start modifying parts where if something fails it'd gonna fall back on them. While there would be many people that could and do cut and weld a booster push rod making sure that it all lines up perfectly so when they find themselves heading towards a tree and smack 150-200kgs on the pedal in panic out doesn't bend and fail, Joe bogan might just cut it with a hack saw and tack it in a few spots in which case it's just a matter of time.. it's prob easier just to ban all welding full stop.. Â Cletus, what modifications to booster push rods are legal? Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 13, 2015 Author Share Posted November 13, 2015 Plus a visual inspection can not always tell you what the weld is like under the surface. Quote Link to comment Share on other sites More sharing options...
sr2 Posted November 28, 2015 Share Posted November 28, 2015 from a cert point of view, it is not legal to weld a brake push rod Apologies for thread dredging but a link posted in another thread suggests that as long as it's not a butt weld you can weld a brake push rod? Â See 2.3 (14) and 2.3 (15). Â http://www.lvvta.org...ing_Systems.pdf Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 28, 2015 Author Share Posted November 28, 2015 I'm not sure how you managed to do that with the link haha 1 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 28, 2015 Author Share Posted November 28, 2015 Thanks for that! Brake pedals and brake pedal push-rods used within low volume vehicles: (a) may be modified by taking into account the specifications provided within the appropriate Low Volume Vehicle Technical Association Incorporated Member Association Technical Manual; and ( must not be lengthened or shortened by the process of solely butt-welding the two or more sections togethe Welding with a sleeve would be very easy. I decided to machine up an aluminium clevis (not exactly but don't know what else to call it) that screws over the pushrod. Just a bit stuck as we don't have a 1/2" unf die at work AND I'm too cheap to buy one. Quote Link to comment Share on other sites More sharing options...
sr2 Posted November 28, 2015 Share Posted November 28, 2015 I'm not sure how you managed to do that with the link haha LOL, I haven't a clue either! Quote Link to comment Share on other sites More sharing options...
Mitchfromhillcrest Posted November 28, 2015 Share Posted November 28, 2015 Thanks for that! Brake pedals and brake pedal push-rods used within low volume vehicles: (a) may be modified by taking into account the specifications provided within the appropriate Low Volume Vehicle Technical Association Incorporated Member Association Technical Manual; and ( must not be lengthened or shortened by the process of solely butt-welding the two or more sections togethe Welding with a sleeve would be very easy. I decided to machine up an aluminium clevis (not exactly but don't know what else to call it) that screws over the pushrod. Just a bit stuck as we don't have a 1/2" unf die at work AND I'm too cheap to buy one. Â I may have one at work cuzzzzzzzzy. Ill have a look on monday for yaaaaaa. Get my number of Gregosaurus. or fb me Quote Link to comment Share on other sites More sharing options...
cletus Posted November 28, 2015 Share Posted November 28, 2015 Apologies for thread dredging but a link posted in another thread suggests that as long as it's not a butt weld you can weld a brake push rod? See 2.3 (14) and 2.3 (15). http://www.lvvta.org...ing_Systems.pdf Some of the standards need updating, hobby car manual is slightly different and says a pushrod can't be welded or have any join apart from attachment of end fittings. The one exception to the no welding a pushrod is when using a complete OE unmodified one from a production vehicle 1 Quote Link to comment Share on other sites More sharing options...
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