Nissin Caliper - Repair or replacement options?

[Rimmer]

Hi,

Right so I got myself in a bit of a mess when trying to bleed my rear brake as I was loosing a lot of pressure - it just wasn't breaking unless I pumped the brake at least 20 times.

The top part of the bleed nipple was broken and whilst trying to get out the remainder of the hollow screw with an easy-out, the easy-out broke staying stuck in the hollow screw. I tried to drill it out, using titanium drill bits but it didn't do much good and if anything I've now made a bad situation worse.

I spoke to a Nissin specialist who told me that basically the only way to do anything about it now would be to go to a spark erosion specialist - but he said they're expensive and would easily cost the price of a caliper - which is my other option.
Now this particular model of Nissin caliper (the stock one of my 77 CB750, I believe it's the 9V3 model) is not easy to come by. There are a few kicking about on ebay but I doubt that they would come in very good shape.

So I have a few questions:
- Has anyone used a spark erosion specialist and could share their experience (and perhaps details, particularly if they're in the London area)
- Has anyone replaced an identical caliper and if so with what.

I'm really looking for some input as I've been using only my front brake for the past few weeks and I really can't keep this up much longer!
Thanks!

[Bryanj]

Drill it right out oversize and use a bleed nipple repair kit, I have some i imported from the states and I know there are pictures somewhere on the site

[ka-ja]

Hi,
     Just bear in mind that spark erosion is not that accurate, and with the easy-out being of similar hardness to a screw tap, the erosion could effect the surrounding metal more than the hard center.

[mick]

Here you go Rimmer these are the bleed nipple repair kits Bryan was talking about you don't get the tap or drill bit with the kit  cheers Mick.

[Rimmer]

Thanks for this guys, this is great help!
Will get onto getting the kit and other tools right away, will post pics of the job before and after if it can help anyone else.

Cheers!

[mick]

Hi Rimmer i'm not sure if there is a supplier for those kits in the uk? I know Bryanj was selling some, I bought my kits from the States I got a forum member on the sohc4.net site to buy them for me and post them to me  cheers Mick.

[Bryanj]

I still have some left, I imported them via a US site member but got hammered by HMRC for import duties and tax so they cost me £13 per kit which is what you can have one for plus the royal mail postage mate.

They are for the small bleed nipple but I also have one adaptor left where you tap bigger for the big bleeder and fit that first(K0-K6 front calipers)

if you look at

http://forums.sohc4.net/index.php?topic=103641.0

there are some good pics but he got the tap size wrong for the small kit, it should be 1/8NPT and the drill sizeis 21/64 or 8.3mm

[Rimmer]

Thanks Bryanj, I'll send you a msg for the details