I've had a real slow leak for a while and now it is leaking much faster.
I can't find a source for a new valve assembly. Can these be rebuilt, perhaps with new O rings?

I bookmarked this page incase mine started leaking:
https://bbs.zuwharrie.com/content?topic=137285.0;topicseen

I bookmarked this page incase mine started leaking:
https://bbs.zuwharrie.com/content?topic=137285.0;topicseen

Excellent. Thank you ZUK-E. I may have found a used one but it's nice to have another option.

I had the same problem. The alternative solution of add in a manual one was not good because if it leaked you could wind up with no brakes at all. A used one might go bad again. I found one at a site called Megazip. It comes from Japan and takes about 2 weeks. Expensive but no choice.

https://www.zukiworld.com/forum/technical-discussion-beginner-repair/proportioning-valve-leaking!/

I had the same problem. The alternative solution of add in a manual one was not good because if it leaked you could wind up with no brakes at all. A used one might go bad again. I found one at a site called Megazip. It comes from Japan and takes about 2 weeks. Expensive but no choice.

https://www.zukiworld.com/forum/technical-discussion-beginner-repair/proportioning-valve-leaking!/

Megazip appears to be a great site even if just for reference. I looked and found this for part 27 of the picture at https://www.megazip.net/zapchasti-dlya-avtomobilej/suzuki/samurai-8583/sj413-18320/sj413-my-86-88-328890 :

51910-83110-000
VALVE ASSY,PROPORTIONING
1 pc of this part is required in this component. Price is shown for 1 pc.
This part is discontinued by manufacturer or sold out.

You can also try amayama.com, partsouq.com and ssg.asia