Undoing brake unions / assembling shoes
Discussion
Yet again I see myself about to take on a car that needs new rear shoes and that means it'll no doubt need wheel cylinders too.
Every single f
king time I have an utter mare with this, undoing the bloody rusted seized unions, rounding them off, having to replace st loads of brake pipe because I've ruined it 
So, mechanical gods of PH, what protips do you have for doing this without such carnage? Heat? Penetrating oil? More swearing? Better tools?
Also - assembling brake shoes with those bloody springs.... there's got to be a knack to it but is it just a matter of experience / trial and error?
Every single f
king time I have an utter mare with this, undoing the bloody rusted seized unions, rounding them off, having to replace st loads of brake pipe because I've ruined it So, mechanical gods of PH, what protips do you have for doing this without such carnage? Heat? Penetrating oil? More swearing? Better tools?
Also - assembling brake shoes with those bloody springs.... there's got to be a knack to it but is it just a matter of experience / trial and error?
As far as the pipework is concerned I expect it to be steel, rusty & siezed. Probably with chewed up corners on the unions.
I'm rarely disappointed!
Which is why I keep a roll of Cunifer, various unions & a flaring tool in the garage.
Best advice if its brake shoes you've not done before - or not done for a while - either draw diagrams of what goes where or take lots of photos.
The shoe hold downs can be a PITA to get the springs & retainers back on. I've got the proper tool but find a small pair of mole grips work just as well for the push and twist required.
The pull-off springs can also be difficult but I find that doing the top or bottom of both shoes first & then seating the other end of one shoe makes fitting the other spring & levering the end of that shoe into position is easier than trying to fight the lot.
As you say, the more you do the easier it should get.(Well that's the theory anyway)
I'm rarely disappointed!
Which is why I keep a roll of Cunifer, various unions & a flaring tool in the garage.
Best advice if its brake shoes you've not done before - or not done for a while - either draw diagrams of what goes where or take lots of photos.
The shoe hold downs can be a PITA to get the springs & retainers back on. I've got the proper tool but find a small pair of mole grips work just as well for the push and twist required.
The pull-off springs can also be difficult but I find that doing the top or bottom of both shoes first & then seating the other end of one shoe makes fitting the other spring & levering the end of that shoe into position is easier than trying to fight the lot.
As you say, the more you do the easier it should get.(Well that's the theory anyway
)Edited by paintman on Friday 7th November 10:15
I have some spring pliers which have a hold down remover built into the end, they are fab and cheap, wish I'd bought them years ago.
http://www.amazon.co.uk/VS035-Brake-Shoe-Spring-Pl...
As for bleed nipples, PlusGas is the stuff you need, preferably left for a bit to actually work its magic. A tickle over with a small wire brush, and use the smallest 1/4" six sided socket that will fit over the nipple to do the initial crack off, and if that doesn't work then resort to mini-stilsons or mole grips.
I always seem to end up replacing the nipples on Ford rear wheel cylinders. They are supposed to be 11mm head but often you need to go as small as 9mm they are so crusty! They are literally pence to buy so it may be worth getting them in advance and just replacing them anyway. A bit of PTFE on the threads can help with vacuum bleeding too.
For unions, again PlusGas and time are important here. A clean up with a small wire brush will help you get a good purchase.
As a rule of thumb always use the best fitting tool you can, and clean the head of the fastener. If you've used good penetrating fluid, cleaned the fixing and used well fitting tools, if it still rounds off then you know you did all you could.
http://www.amazon.co.uk/VS035-Brake-Shoe-Spring-Pl...
As for bleed nipples, PlusGas is the stuff you need, preferably left for a bit to actually work its magic. A tickle over with a small wire brush, and use the smallest 1/4" six sided socket that will fit over the nipple to do the initial crack off, and if that doesn't work then resort to mini-stilsons or mole grips.
I always seem to end up replacing the nipples on Ford rear wheel cylinders. They are supposed to be 11mm head but often you need to go as small as 9mm they are so crusty! They are literally pence to buy so it may be worth getting them in advance and just replacing them anyway. A bit of PTFE on the threads can help with vacuum bleeding too.
For unions, again PlusGas and time are important here. A clean up with a small wire brush will help you get a good purchase.
As a rule of thumb always use the best fitting tool you can, and clean the head of the fastener. If you've used good penetrating fluid, cleaned the fixing and used well fitting tools, if it still rounds off then you know you did all you could.
Toaster Pilot said:
Is the tool actually any good?
Yes. Mole grips have a lot more uses though - although when one of the retainers escapes from them it can take some finding!I'll second Plus Gas. Freeze and release is good too. Or any proper penetrating oil. WD has its uses, but this isn't one of them.
Edited by paintman on Friday 7th November 13:46
I normally use "TripleQX Maintenance Spray" (poor mans WD40 from ECP) but I'll buy some Plus Gas just for this. Had good results with "WD40 Professional Penetrating Oil" (much different to the normal blue tin stuff) but it's as expensive if not more so than PG and I've seen so many people rave about it now
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