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CB450 disc brake - caliper rebuild issue

1K views 1 reply 1 participant last post by  caseyR1978 
#1 ·
Hello, I have a '73 CB450, currently trying to rebuild the front disc brake caliper. The issue is the piston–for the life of me I can't get it back in there. I've tried (per other posts)
• obsessively cleaning the channel that the seal sits in, to ensure there's no debris
• lubing the seal/piston with brake fluid
• freezing the piston before inserting
• stretching out the seal before inserting into the channel
• making sure the seal isn't twisted/seated correctly.
• being super careful to try and put the piston in straight

From what I understand I should be able to firmly push it in with my hands/palm. But not force it.

I understand the clearance is super tight, but I'm stuck, and asking if anyone has any other tips?
 
#2 ·
Finally got it...for anyone that happens on this post, also stuck in brake Purgatory like I was, here's what I did:
• ended up springing for a new caliper body - the original had some pitting/rust from old bad b-fluid so I figured better safe than sorry
• I put the caliper piston in my freezer until good and cold, to try and shrink it as much as possible
• stretch a new seal as per others' instructions, then insert into the body - make sure its not binding/twisted
• lube up that seal and piston with brake fluid like your pouring gravy over your turkey on thanksgiving - more the better imo
• really take care to insert the piston straight in, then twist the piston as you begin to push down. You'll know if it isn't going in–as you can push with all your weight and it wont budge. Stop in that case and start over. The piston should slide in with minimal force.
 
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