Brake line fitting seized in caliper - help

[shrub]

I have a 78 BMW and I am stripping the calipers, but the bleed nipple and line fitting have siezed solid. I have soaked them in Wurst Rost Off, shocked them with a hammer and even the last resort vice grip won't shift them. Any ideas? My limited knowledge suggests heat is not a good option but there must be something.

[imdying]

More Rost Off (it's good stuff) and more waiting. A little heat won't hurt, just don't go nuts with a welding torch.

If you put the fitting in the vice and tighten it till it screams, you should be able to wind the caliper off the fitting (instead of vice versa) a little easier.

[Paul in NZ]

Brembo caliper? Yeah - they all do that sir. Get the pistons out (if you can) and a bit of heat. Fortunately new ones aint all that dear.

If its a 78 it may have come with chrome pistons - ditch em for alloy ones.

[shrub]

Brembo caliper? Yeah - they all do that sir. Get the pistons out (if you can) and a bit of heat. Fortunately new ones aint all that dear.

If its a 78 it may have come with chrome pistons - ditch em for alloy ones.

No, not Brembo. I'd ditch them in a heartbeat for a set of modern Nissin or Brembo calipers, but it needs vinning and I may be wrong but I get the feeling that the little men in white coats will look sternly upon such frivilous and dangerous modifications. Or am I wrong?

[shrub]

More Rost Off (it's good stuff) and more waiting. A little heat won't hurt, just don't go nuts with a welding torch.

If you put the fitting in the vice and tighten it till it screams, you should be able to wind the caliper off the fitting (instead of vice versa) a little easier.

I'll try that.

[Katman]

No, not Brembo. I'd ditch them in a heartbeat for a set of modern Nissin or Brembo calipers, but it needs vinning and I may be wrong but I get the feeling that the little men in white coats will look sternly upon such frivilous and dangerous modifications. Or am I wrong?

They'd never know.

[Paul in NZ]

You sure? I thought for sure a 78 BMW would have Brembo F08 / F09 - almost everything else made in europe did... Crazy germans

[Spearfish]

They'd never know.

+1
All they like to have is the piece of paper with the disk thickness and either pads or shoes are inside the wear limits.

[shrub]

They'd never know.


+1
All they like to have is the piece of paper with the disk thickness and either pads or shoes are inside the wear limits.

That is very, very good news. What about losing the idiotic remote master cylinder arrangement under the tank and even the entire front end? Perfect world will be modern Japanese suspension, braking and electrics with ancient Kraut mechanicals.

[ducatilover]

I have a spare set of ZZR600 Tokico (sp?) front brakes (and a twin piston rear) with master cylinder if you are looking for a cheap, decent upgrade. The ZZR6 stops rather well with them :innocent:

[willytheekid]

I have a 78 BMW and I am stripping the calipers, but the bleed nipple and line fitting have siezed solid. I have soaked them in Wurst Rost Off, shocked them with a hammer and even the last resort vice grip won't shift them. Any ideas? My limited knowledge suggests heat is not a good option but there must be something.

Gidday Shrub :)

You wanna grab your self a can of loctite "freeze n Release", pritty good stuff!
-in fact I have a 1/4 can of freeze spray in the garage if you want to try it (got all my "problem" bolts)
Think I got it from Repco or Super chep Auto ? (was awhile ago)

PM me if you want to borrow the last of my can :)

[imdying]

I'll try that.It's pretty ghetto, I'll admit that... but I've had bleeders out of things that look like they've spent time in the ocean by using that technique. After some penetrating/heat loving in that particular case... but that was about as worst case as it gets (excluding bleeders that are actually snapped off of course).

[HenryDorsetCase]

is it because the bleeders are steel and the calipers alooominum, and the brake fluid which is just an arse of a stuff that you get these issues? I had a real nightmare with a set of CB400 ones I had. Those calipers bolt together though, and I had spares so in the end I binned the half that wouldnt move, and swapped it for one that could, then rebuilt that. Horrible job.

[shrub]

is it because the bleeders are steel and the calipers alooominum, and the brake fluid which is just an arse of a stuff that you get these issues?

yeah, it's galvanic corrosion. When you place two different metals together with a corrosive or conducting solution between them they kind of fall in love and bond and hydraulic fluid absorbs water and microscopic metalic particles.

Jeez, I was taught that over 30 years ago and I still remember it.

[Spearfish]

I missed the year our your bike, technically you don't need the disk thickness for a bike older than 1980.
Depending on where you go you can get asked all sorts of things, the first place I had a chat to wanted a disk thickness and the rear drum diameter of a 76 bike even thought I told him it had only drums.

I'm not sure how they would view a front end change over but I do think its worth finding someone who knows when different rules apply and in what years to vin the bike. In other words the local vtnz could be a little frustrating.

[shrub]

I missed the year our your bike, technically you don't need the disk thickness for a bike older than 1980.
Depending on where you go you can get asked all sorts of things, the first place I had a chat to wanted a disk thickness and the rear drum diameter of a 76 bike even thought I told him it had only drums.

I'm not sure how they would view a front end change over but I do think its worth finding someone who knows when different rules apply and in what years to vin the bike. In other words the local vtnz could be a little frustrating.

It's a 78, and that's good news. I'll do some asking around down at the local AA and see what I can learn. The rear rotor has some reall nasty grooves in it and I will probably have to replace that, but am working backwards one step at a time.

[Brian d marge]

As has been said before , heat you can get those calipers quite hot and of course the seals will be toast , then sharp raps on the bleed nipple if you can at the same time turning. ( u can save the nipple , but vice grips may have killed it already )

the freeze spray is doing a similar thing .. a difference in expansion rates

WORST CASE , Drill it out ie take the radial pressure away , it can be done and if you are careful you wont even damage the threads....

Worst Worst case, to test if they are salvageable, ie worth saving,,, Large volume of water , and apply the flotation test, I usually use Bromley sewage works. if they float they are worth saving


Stephen

[Kickaha]

You sure? I thought for sure a 78 BMW would have Brembo F08 / F09 - almost everything else made in europe did... Crazy germans

BMW went Brembo on the front in 1978 although I have seen some bikes with ATE calipers on the front with a brembo rear caliper

My 1977 has ATE front with drum rear


That is very, very good news. What about losing the idiotic remote master cylinder arrangement under the tank and even the entire front end? Perfect world will be modern Japanese suspension, braking and electrics with ancient Kraut mechanicals.

If you're going to stay with the ATE calipers then look for a later throttle/brake assembly off the monoshock bikes and some decent pads


The rear rotor has some real nasty grooves in it and I will probably have to replace that, but am working backwards one step at a time.

Wallace at Marshlands engineering can get some made up for you, he did the 290mm discs for my BMW

Actually i got some discs which might be ok from doing my big brake kit if you want them

[shrub]

If you're going to stay with the ATE calipers then look for a later throttle/brake assembly off the monoshock bikes and some decent pads
Actually i got some discs which might be ok from doing my big brake kit if you want them

I might take you up on that. At this stage my plan is to get it legal and registered, then replace the entire braking system with something a little more contemporary, although if I can get through the vinning process with later model forks and calipers and a proper master cylinder setup I will. I'm not after performance from the old girl, but I really like grunty brakes with feel so I can slow down fast when I feel the need, and a cable operated master cylinder looks like it will offer all the feel of a leather condom.

I doubt the standard front forks come close to a set of 90s onwards forks, so they are likely to be replaced, which I will need to do if I want to fit better calipers. It has recently rebuilt Konis on the back which should do me fine.

[_STAIN_]

+1 line it up carefully and give the bleed nipple a good smack with the hammer



As has been said before , heat you can get those calipers quite hot and of course the seals will be toast , then sharp raps on the bleed nipple if you can at the same time turning. ( u can save the nipple , but vice grips may have killed it already )

the freeze spray is doing a similar thing .. a difference in expansion rates

WORST CASE , Drill it out ie take the radial pressure away , it can be done and if you are careful you wont even damage the threads....

Worst Worst case, to test if they are salvageable, ie worth saving,,, Large volume of water , and apply the flotation test, I usually use Bromley sewage works. if they float they are worth saving


Stephen

[FROSTY]

Shrub--GIVEN you fully intend to toss the whole lot in the bin can I ask why you are bothering? Why not do what you need to do regarding getting the pistons going in and out then hand fill the caliper with fluid through the hose bolt.If you rotate the caliper so this is the highest point you should be able to bleed it there too.
Not a normal recomendation I'd make but it might get the bike legal so you can fit decent stuff.

[HenryDorsetCase]

here's your new front end. in fact why not take the rolling chassis from this and staple and zip tie the old two banger in there? you'd have to convert it to chain drive maybe (or a belt, like a Harley).

that'd be cool!


http://www.trademe.co.nz/motors/motorbikes/motorbikes/sports/auction-391863871.htm

[Kickaha]

I might take you up on that. At this stage my plan is to get it legal and registered, then replace the entire braking system with something a little more contemporary,

If you get the slightly later front end (79/80ish)which has the Brembo 08 calipers you can get way better performance from the brakes and a 4 pot conversion is also really easy to do on them

[shrub]

If you get the slightly later front end (79/80ish)which has the Brembo 08 calipers you can get way better performance from the brakes and a 4 pot conversion is also really easy to do on them

That sounds like the way forward, thanks.

[Kickaha]

That sounds like the way forward, thanks.
The only thing I'm not sure about is if the wheels are a straight swap, I know the wire wheels don't swap straight in without using a GS front hub