Brake calipers oil chanel failure
Turbo Mini Forums

Bought some used minispares 7.5" alloy calipers some time ago, only to find out this weekend wend trying to bleed the brakes a airline crack from the oil feed, scratch the airline and a huge hole appears...

Need some advice, tig weld and re-drill the oil feed?
Blank the oil feed and run a exterior pipe? (have to check for clearance)

you may be able ? to drill and tap it and put a suitable metric grub screw in there with some high strength locktight in ?

Edited by BENROSS on 9th Mar, 2015.

Replace it - It's too risky to attempt a repair.

Even by my standards, it's not economical either.

Edited by PhilR on 9th Mar, 2015.

you may well be right phil

Is that a hole in it too ?

And looks like the disc has been rubbing on it as well ?

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

never ever compromise on safety !

fiddling with horsepowers is a pleasure, doing that with brakes is a nightmare !

I´ve tried grub screws on some bike brakes drilling and tapping and never made them to seal properly, using steel balls grub screws work sometimes.

Ya, seams something has bean rubbing on it, bought used from ebay, very bad deal indeed....

The calipers is lost so I should give a try... and at this moment I cant afford to buy a new set.

Edited by R.Rodrigues on 9th Mar, 2015.

Get it tig welded up imo

Get it tig welded up imo

Scrap. Disc has been rubbing it making it so thin it has cracked. All you will do with a TIG is melt the paper thin material that's left back.

I'd agree with the general consensus. While some things can be repaired, brakes aren't something you want to risk. Given what has already happened, i don't think you can rule out any other future failure. Scrap them I'm afraid

fucked drive flanges?

Bin em!

If something is worth doing, it's worth doing half of.

This a hell of a coincidence because over on another forum we have a discussion on re -sleeved brake parts and there have been two incidences if cracked cast iron brake cylinders. It was suggested (briefly !) that they could be repaired but, as on here, common sense prevailed.

One mistake on brakes is one too many.

If it was just a small amount of wear that had opened up the oil way and absolutely no crack, I'd consider welding it up (depending on the scale and position of the damage).

...But once you start cutting, you'll probably find the crack goes deep. Would you still consider TIG-ing it if it was 50% through? What if it was split in half?

Paypal disputes can now be opened up to 180 days from purchase. If that's not an option, then take a sledge hammer to it before you're tempted to fix it.

Edited by PhilR on 10th Mar, 2015.

Just pass my welding man this morning and he says to try to weld, there is no visible crack it must have open because its so thin, I should try to weld and do a blank spacer to put it on the press and do a pressure test, have to see if I have any gauge up to 1500psi or close, 1500psi should do the job i think...

Dont know anything about this calipers, the other half is intact as the spacer,for vended disc, and the right side is also ok, only this side seams to be damage.

By all means endanger your own life, but if your repair should fail and you knock down a bunch of nuns a young mother, her toddler and a baby in arms on your head be it!

Edited by John on 10th Mar, 2015.

If something is worth doing, it's worth doing half of.

I'm confused, as your first post suggests it has a "hairline crack", but now you say there's no crack.

Be very cautions about advise from someone that has something to gain (your money). As long as he tells you to go and test it, he can pas the responsibility back to you and wash his hands of it. Also, unless he repairs calipers every month, how much do you value is his advise?

Your welder may be the best welder in the world, but is he an engineer? The section you want to weld sees the highest stress on the caliper. It's already thinned out and those groves are perfect places for fatigue cracks to start with repeated loading and unloading of the brakes. Holding pressure is one thing, but that doesn't mean there aren't internal cracks, but you haven't even mentioned any form of crack testing, or putting the caliper under repeated loads that generate the same forces as when braking.

Bin it.

Just don,t do it !

Don't even consider using these now they are scrap

second pic looks like its cracked to me from the oil feed hole out towards the worn hole
well both pics tbh

Edited by Brett on 10th Mar, 2015.

Yes i moved to the darkside

Instagram @jdm_brett

Sorry for my English, wend things start to be more technical this is my best.

Ok im talking on weld a brake caliper I understand all the risks and will not be on the road unless i could test it, off an on the car, and on a no traffic road. All I can do at home is a pressure test.
Probably will put some wheels so a can move the car around the garage for some time, because i just cant afford new calipers right now, conversion rates are to hi.

The crack was smaller than the hole, I think because someone or something grind it and its so thin that open whit the pressure, I scratch the crack and the hole is the result of the area that is so thin I could remove like aluminium foil, so the crack its not really a crack its the failure from the thin area made by something or someone grinding it.

So welding this hole is different from a "airline crack" as I initially said and cause some confusion, this guy welds combustion chambers every moth, is a friend and probably do-it for nothing, is opinion maters to me, as all yours turbominis users....

Seams I win another trophy for the shelf...

Edited by R.Rodrigues on 10th Mar, 2015.

the only thing they can be used as on a car now is as a fucking wheel chock, they are scrap my friend.

On 5th Oct, 2014 Shauna said:
What that's crazy, you go commando hahaha! How heavy is your helmet ?

just some last photos from how they look after the cleaning earlier today,

Edited by R.Rodrigues on 10th Mar, 2015.

It looks like you've used a steel wire wheel? This will just move the aluminium around and hide any cracks if there are any.

What if it's a heat treated alloy (a fairly good chance) ? If it is, then your welding could leave the part weaker than when you started. You might only find out one day when you really need your brakes and push the pedal hard.

What if this is an un-weldable or hard-to-weld alloy and you choose the wrong filler wire? It may hold long enough to do a pressure test, then fail once installed.

Sorry R.Rodrigues, you need another plan

Edited by PhilR on 10th Mar, 2015.