Help identify leaking Grohe valves

[Leaky]

Hello,

Need help finding parts and troubleshooting. We have purchased a place with a Grohe shower that has developed a slow drip from the shower head . When I went to take a peek inside it looks like the shut off valves also have slow leaks.

The non-return valves require a 3/4 inch socket to remove, and when I removed one I. discovered a rotting bit of plastic that appears to come from some other valve.

Would appreciate it if anyone know what model this is, and what parts need to be replaced to solve the various leaks.

Thank you ahead of time.

 

[Breplum]

Terry has these blow ups

https://terrylove.com/forums/index.php?threads/help-removing-grohe-grohmix-faucet-cartridge.68741/#post-646022

 

[Sponsor]

 

[Reach4]

Interesting that that stop valve has a strainer.

 

[Marlinman]

Your valve is 34900

Volume control cartridge is 45882

 

[Leaky]

Thank you for the great inputs. I don’t think the valve is the 34900 because the suggested return valves in the diagram don’t match. I picked up the GROHE 1411600M and they are too small.

Was there a similar valve in a larger size in the 90s? If so would the volume control cartridge also be a larger size?

Again, much appreciated.

 

[Marlinman]

The 34900 is a 1/2" valve. I'll get the 3/4" valve numbers tomorrow. And yes if the thermostatic valve is 3/4" the volume control valve normally will be also.

 

[Marlinman]

The 3/4" thermostatic valve is 34419
The 3/4" volume control cartridge is 45888

 

[Leaky]

Thank you very much! Will replace those parts, and hope for the best .