willie Posted July 29, 2021 Share Posted July 29, 2021 I bench bleed a reconditioned master cyl but as i was carrying it to the car it was leaking out of both treaded holes (lines). Is this normal? Is it because the "O" rings need to swell up? I dont want to connect the lines yet because i know i have to chance the brake lines first. Just thought this master leaking was not right. THX Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted July 29, 2021 Share Posted July 29, 2021 Not really sure I've always left the hoses connected and put under the cover until I got it bolted up to car. Is this a master you rebuilt or something you bought? I will never use a rebuilt or reconditioned master cylinder. The new ones are so much better and not that much more expensive. Quote Link to comment Share on other sites More sharing options...
Canuck Posted July 29, 2021 Share Posted July 29, 2021 I’ve always bench bled the MC using the plugs provided. I leave the plugs in during installation and don’t remove them until I attach the lines. 1 Quote Link to comment Share on other sites More sharing options...
jft69z Posted July 29, 2021 Share Posted July 29, 2021 It is normal for fluid to leak out of both holes in the case you're describing. That is sometimes a way to gravity bleed the system when it's installed in the car too. Open the bleeders & let it flow. Also a troubleshooting test to see if the hoses are collapsed, etc. Conversely, lets say you're replacing a front caliper & don't want to put plugs in the line or have it gravity bleed out on you. You can prop the brake pedal down just a little bit & it will stop the flow of fluid (use a prop rod, or snowbrush works good too, lol). Keep in mind, the brake lights will be on, so if it's a long term thing either pull the fuse or the bulbs, but for a short term solution it works great. I've done it for many years in the shop with no issues. 2 Quote Link to comment Share on other sites More sharing options...
willie Posted July 30, 2021 Author Share Posted July 30, 2021 Thanks guys, My plan is to change the hoses and then open the bleeder valves and let it just bleed out for a few days into separate buckets. Then go from there. Hopefully dont have to change any calipers. LOL Thanks guys Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 30, 2021 Share Posted July 30, 2021 6 hours ago, willie said: Thanks guys, My plan is to change the hoses and then open the bleeder valves and let it just bleed out for a few days into separate buckets. Then go from there. Hopefully dont have to change any calipers. LOL Thanks guys That should not take a few days. Possibly 10 minutes for the front then close the caliper bleeders and 10-15 to get to the rear. Don’t let the master run dry or you get to start over. Ask me how I know about that. You see I like to do things twice. Um ah too make sure that it is right. lol 😂 1 Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted July 30, 2021 Share Posted July 30, 2021 1 hour ago, Dtret said: That should not take a few days. Possibly 10 minutes for the front then close the caliper bleeders and 10-15 to get to the rear. Don’t let the master run dry or you get to start over. Ask me how I know about that. You see I like to do things twice. Um ah too make sure that it is right. lol 😂 Agreed you don't need a few days just a few minutes. And correct do not let the master go dry. Quote Link to comment Share on other sites More sharing options...
jft69z Posted July 30, 2021 Share Posted July 30, 2021 And when Dennis says 'you get to start over', that means taking the master cylinder off to bench bleed it again. That would suck... ask me how I know about that too, lol. Quote Link to comment Share on other sites More sharing options...
Dtret Posted July 30, 2021 Share Posted July 30, 2021 58 minutes ago, jft69z said: And when Dennis says 'you get to start over', that means taking the master cylinder off to bench bleed it again. That would suck... ask me how I know about that too, lol. I try to look at the positive side. Practice makes perfect. Quote Link to comment Share on other sites More sharing options...
willie Posted July 31, 2021 Author Share Posted July 31, 2021 I know you guys are correct but do not have alot of time this weekend so trying to get something done. Yes i understand about letting master run dry, i also been there done that. LOL Quote Link to comment Share on other sites More sharing options...
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