What Brake Hose Bolt do I need for GRX brake levers?
 

I just found out the hard way that the hose bolt that XT uses is a little bit narrower in diameter and possibly a different thread pitch to the one required for a GRX "brifter". Does anyone know what Shimano part this would be? Are the olives and barbs different as well?

Is it possibly SB-BH59 ?

Edit: IT is NOT this. The BH90/M9 parts are compatible (see posts 6 and 7 below).

I haven't checked, and leave that to the OP, but I believe that Shimano's site has pages of exploded views with parts identified by number.

As I said, it's purely a suggestion for the OP to try their luck at Shimano's site, which it he likeliest place to get a right answer to this question.

They have the Dealers Manual and User's Manual but no Exploded View for the GRX "brifters". I checked Shimano's site and several on-line vendors before posting here.

I ordered the BH59 and BH90 from Amazon. Hopefully one of those two will work.

The recommended calipers diagrams for the GRX brifters show the parts you were probably looking for.

ST-RX600 / ST-RX815 - BR-RX810
https://si.shimano.com/en/pdfs/ev/BR...X810-4585B.pdf

ST-RX400 - BR-RX400
https://si.shimano.com/en/pdfs/ev/BR...X400-4574C.pdf

Thanks. That is exactly what I needed. My mistake was thinking it would be part of the brifter rather than the caliper (which I guess also explains why it didn't come in the box with the brifter).

In summary:


https://cimg3.ibsrv.net/gimg/bikefor...41f0806e4a.png

M9 corresponds to SB-BH90 I think, which is one of the two I ordered from Amazon.

BH90/M9 arrived and appears to fit.

Again, many thanks!

Ordering from Amazon is a real joy. The first one didn't fit. An empty envelope (that's a first) for the other one.

I've now ordered what is hopefully the correct ones from a bike shop 3000 miles from here.