Corroded brake bleed nipple - best way to extract?
Discussion
If you already have a new bleed nipple then give the old one a few good smacks on the end with a hammer before even trying to budge it. Also might be worth sawing the end off so you can get to the hex more easily and tap a socket onto it. File the rust off the flats first and try with a 6 point socket as your spanner is likely to be 12 point and will round it off. If that started off life as a 9 mm hex then an 8 mm socket will probably work.
I'd wire brush as much as I can off it, heat up with a blowtorch, and then dowse some Plusgas on it, before trying to unscrew it with a good socket. I think there's a good chance it'll round off whatever you do, though, at which point good locking pliers clamped on VERY tightly are my go-to.
InitialDave said:
I'd wire brush as much as I can off it, heat up with a blowtorch, and then dowse some Plusgas on it, before trying to unscrew it with a good socket. I think there's a good chance it'll round off whatever you do, though, at which point good locking pliers clamped on VERY tightly are my go-to.
Guys, all this is a wast of time,you never heat up a wheel cylinder.It could distort the bore and affect the seals. A new quality cylinder will cost between £12 - £15 ,remember this is a safety critical part. By the way,when fitting the new cylinder cover the bleed nipple with lots of brake grease to stop it going rusty and seizing.Manky brake fittings:
Put the brake spanner back in your tool box.
Buy a stainless or titanium replacement nipple.
Once you have gone at it with spanners and mole grips its too late. Try this first.
Before doing ANYTHING:
Tap the nipple with a hammer many short taps this will distort the nipple a little.
Heat it up with a heat gun, coulple of kettles of boiling water or blowtorch whatever you have.
Tap it again with a hammer
Then get a good fitting socket.
Use the "T handle" from your socket set NOT THE RATCHET and not a spanner.
Tighten the nipple slightly.
Undo.
The T handle set equally will allow you apply a purely rotational force to the nipple. A ratchet or spanner applies a sideways force too that snaps the nipple.
Put the brake spanner back in your tool box.
Buy a stainless or titanium replacement nipple.
Once you have gone at it with spanners and mole grips its too late. Try this first.
Before doing ANYTHING:
Tap the nipple with a hammer many short taps this will distort the nipple a little.
Heat it up with a heat gun, coulple of kettles of boiling water or blowtorch whatever you have.
Tap it again with a hammer
Then get a good fitting socket.
Use the "T handle" from your socket set NOT THE RATCHET and not a spanner.
Tighten the nipple slightly.
Undo.
The T handle set equally will allow you apply a purely rotational force to the nipple. A ratchet or spanner applies a sideways force too that snaps the nipple.
steveo3002 said:
fit new cylinders...wont be much more ££ than trying every miracle penetrant , chances are theyre well past it anyway
At long last a sensible reply that agrees with mine. By the look of the OP`s image the rear end looks as if it came from the deck of the Titanic. Everything is old,corroded and well past its sell by date,that nipple will never come out and by the look of it the flexi hose could be difficult as well.
was8v said:
The T handle set equally will allow you apply a purely rotational force to the nipple. A ratchet or spanner applies a sideways force too that snaps the nipple.
OK, I get what you mean but there are many ways of achieving the same end result.It is the way the tool is used that dictates the amount of rotational force & the amount of bending force to the length of the fastener (in this case bleed nipple) not the tool used.
With all else being equal the best way to get something like this out is by applying the torque in a plane as close as possible to the fixed end of the fastening so a completely flat ring spanner is the best, alas that will likely be difficult to get in/on.
eg, if you were to use a socket/extension/ratchet combination there are 2 main ways of using it.
1 handed without supporting the ratchet end/2 handed with supporting the ratchet end while applying torque to the handle end.
When used 1 handed by the handle alone there is every likelihood that there will be far too much bending (over rotational) force applied & the nipple could break.
Use 2 handed & supported correctly the bending force can be completely removed from the equation leaving just rotational torque & increasing the chance of getting it out.
So with the worst tool possible you can still replicate the results of the best tool possible.
Edited by E-bmw on Wednesday 24th October 08:26
Rear cylinders are only around £8 on eBay so it's not really worth worrying about...just replace the buggers.
I did mine yesterday - the trouble came when trying to undo the two 8mm bolts holding it on. You need to use a wobble bar and carefully turn it with increasing force until it clicks loose. I did try a ring spanner but it felt like it might slip so gave it a miss as I didn't want to make more work for myself.
As for the front bleed nipples - don't even start until you apply some heat with a blow torch. Heat is the answer otherwise they snap really easily.
I did mine yesterday - the trouble came when trying to undo the two 8mm bolts holding it on. You need to use a wobble bar and carefully turn it with increasing force until it clicks loose. I did try a ring spanner but it felt like it might slip so gave it a miss as I didn't want to make more work for myself.
As for the front bleed nipples - don't even start until you apply some heat with a blow torch. Heat is the answer otherwise they snap really easily.
I've abandoned any hope of removing the bleed nipple, I was able to hammer on an 8mm spanner but it still wouldn't budge.
I now have a pair of brand new wheels cylinders (£6 a piece on Ebay). But inevitably, as the good Doctor found, the 8mm nuts that hold on the existing wheel cylinder are tricky. Mine are rusted in a similar manner to the bleed nipple - i.e. they are rusted and round off at the slightest touch of a socket.
I've seen a really nasty video on YouTube where somewhere resolved this using an angle grinder on the wheel cylinder itself.
I'm thinking of taking a sharp cold chisel and trying to knock/chop the heads off the 2 bolts? Would this work? If the bolts heads are 8mm they can't be that substantial. I can't get anything else to them, they are tucked out of the way.
I can manage without the car for a day or two but I don't want to end up in a situation that I can't resolve myself. So any solution shouldn't be too ambitious.
And I need to get this done a.s.a.p. as I need to service the wife's car. Then I have a winter project of learning how to rebuild 4 Weber carbs...
I now have a pair of brand new wheels cylinders (£6 a piece on Ebay). But inevitably, as the good Doctor found, the 8mm nuts that hold on the existing wheel cylinder are tricky. Mine are rusted in a similar manner to the bleed nipple - i.e. they are rusted and round off at the slightest touch of a socket.
I've seen a really nasty video on YouTube where somewhere resolved this using an angle grinder on the wheel cylinder itself.
I'm thinking of taking a sharp cold chisel and trying to knock/chop the heads off the 2 bolts? Would this work? If the bolts heads are 8mm they can't be that substantial. I can't get anything else to them, they are tucked out of the way.
I can manage without the car for a day or two but I don't want to end up in a situation that I can't resolve myself. So any solution shouldn't be too ambitious.
And I need to get this done a.s.a.p. as I need to service the wife's car. Then I have a winter project of learning how to rebuild 4 Weber carbs...
Old Merc said:
By the look of the OP`s image the rear end looks as if it came from the deck of the Titanic.
I beg your pardon, I'll have you know the insurance value of the vehicle is £148 Try Irwin Bolt Grip sockets, they've done well for me on many occasions on rusted/rounded heads, including quite a few that I really didn't think they'd manage to get purchase on.
Or yes, simply removing the heads should work, though I think I'd go with a cutting disc on a Dremel (angle grinder probably won't fit in the available space?) rather than a chisel.
Or yes, simply removing the heads should work, though I think I'd go with a cutting disc on a Dremel (angle grinder probably won't fit in the available space?) rather than a chisel.
Thanks chaps.
Getting mole grips or a Dremel onto these bolts isn't possible. An 8mm socket on a universal joint type wrench is about the only way to access them but mine are too corroded.
I did remove the hub spindle assuming the 4 large bolts held the backing plate on. But it didn't budge and I assumed it was welded to the suspension arm. I needed the car so I put it all back together again.
I have subsequently found a video showing that it's held on with 2 rivets! On my next attempt I will drill these out and get it on the bench.
I didn't expect there to be a lot of enthusiasm for my cold chisel idea!
Getting mole grips or a Dremel onto these bolts isn't possible. An 8mm socket on a universal joint type wrench is about the only way to access them but mine are too corroded.
I did remove the hub spindle assuming the 4 large bolts held the backing plate on. But it didn't budge and I assumed it was welded to the suspension arm. I needed the car so I put it all back together again.
I have subsequently found a video showing that it's held on with 2 rivets! On my next attempt I will drill these out and get it on the bench.
I didn't expect there to be a lot of enthusiasm for my cold chisel idea!
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