Brake Caliper Piston Pitting - How much is too much?

Have read in the archive concerns about pitted caliper pistons causing leaking and other problems. I had my caliper pistons bead blasted and noted some pitting. But is there a minimum amount of pitting that would be acceptable? Or is any pitting a bad thing. What is shown is the worst of the 3 and what's showing is all there is. I have attached a photo and would appreciate your thoughts on this. Thanks.

Not sure the pic came through. So trying it again.

I don't think those things cost that much to replace if you are rebuilding the brakes. Z1 Enterprises carries them I think...

Didn't see them at Z1. Partsnmore had some listed but not for the kz900B1, just kz1000. I'll have to cross check the part numbers. It's $29 bucks. I might have to get 3. Better that - than have a fluid leak ruining paint or worse, - brake failure......it's just that I have to pay my most excellent engine rebuilder soon.
Trying to save $$$.

whats the differance between them and kz1000 pistons?

since you have them down that far , I would go back with dot 5 fluid, worth the money

Here are some bikes that used the same piston.

Part # = 43048-006
Part Description = CALIPER PISTON
Model Count = 13
Model Name Year Size Description Type
KH400-A3 76 400 KH400 STREET
KH400-A4 77 400 KH400 STREET
KH400-A5 78 400 KH400 STREET
KH500-A8 76 500 KH500 STREET
KZ750-B1 76 750 750 LTD TWIN LTD STREET
KZ750-B2 77 750 750 LTD TWIN LTD STREET
KZ750-B4 79 750 750 LTD TWIN LTD STREET
KZ900-A4 76 900 KZ900 SPORTBIKE
KZ900-A5 77 900 KZ900 STREET
KZ900-B1 76 900 900 LTD LTD STREET
KZ900-C2 76 900 900 POLICE POLICE
KZ1000-B1 77 1000 KZ1000 LTD SPORTBIKE
KZ1000-B2 78 1000 KZ1000 LTD SPORTBIKE

Maybe you can find one of those listed somewhere.

Jeff is a small operation and MANY parts he COULD sell are still not listed on his web site. I have yet to find ANY vintage bike part that he doesn't have access to that some other sell does.

i wouldnt use those

braze over the pits.. a good metalergist welder can make that like new.. take more time to get out the equipment than to do it

Metalergist welder. Has a nice ring to it. Steve at Z1 said they don't have them in stock but will have them in 3-6 months. OKC. - thanks for the cross reference! Partsnmore might have them in stock, They listed some 1000LTD B1 pistons I think, but they didn't look the same - I'll have to double check. I may heed fixer5000's advice and not use them and fork out about $100 for 3 new ones - unless I can find a metalurgest roaming the streets here in downtown Crane. Thanks for the feedback.

what do the bores inside the calipers look?