Suzuki gt 380 master cylinder

[smokingbanana90]

Hello, I have been getting my gt380's front brake all good to go and I have one problem. So far I have cleaned and rebuilt the caliper, replaced the brake lines. Now on to the master cylinder. I have already cleaned out the holes at the bottom of the reservoir. I've also made sure the return hole was nice and clear as mentioned in the other thread. What I am having difficulty with is cleaning out the bore for the piston in master cylinder. Does anyone have any advice for cleaning out the bore for the piston? Thanks and best Regards!

[Alan H]

BRASS (not brass plated steel) wire brush in a dremel.

[Coyote]

Short of the miserable job of taking it apart I would try this. Remove the resiviour. Get a deep tray and fill it with alcohol. Regular rubbing alcohol. Submerge the MC and work the lever. It may take 20 - 30 pumps but it will expel any crud internally. Just make sure the feed and return hole are submerged. Use alcohol as a little residue left will mix with the brake fluid and eventually evaporate off. NO WATER!

[yeadon_m]

As the m/cyl is 'bare' of rubber parts, I would just sloosh some carb cleaner spray in there, work it around with cotton buds, hardwood scrapers etc. Its almost a chrome-looking bore and may still be quite shiny? brass is OK but it may be more crud in the ends than the walls?
Mike

[Coyote]

I assumed it was still together

[yeadon_m]

ah, you may be right! I ASSuMEd that as the OP referred to the bore, the piston was out? if its not, no way is carb cleaner suitable.....
Mike

[smokingbanana90]

Thanks! I got it all cleaned out and have the rebuild kit installed in the same order as the old parts but it does not seem to build pressure when I fill the reservoir with brake fluid. Are there any tricks to getting the system pressurized?

[Suzukidave]

Are you sure the tiny return bleed hole is clear ( the smaller of the 2 holes in the bottom of the reservoir ) , it doesnt take much to block this tiny hole .

[smokingbanana90]

Thanks for the input everyone. I got the system working now. I ended up using a syringe and pumping the brake lines full of fluid and then bleeding it out.