Need help removing and bleed rear master cylinder

[TroyJackson]

Hey guys. Brand new here and brand new to a Yamaha Venture as well!

I've got a 1983 Venture Royale xvz12 in beautiful shape just need to bleed the rear master cylinder.

Sorry for the dumb question but just trying to figure out how to remove the thing! I got the actual MC off no problem but can't seem to find the bolts for the rear reservoir and don't want to start removing stuff that I don't need to. It's really jammed up in there! If anyone has some advice that would be grand!

Also, when I do get it off I don't seem to see anywhere on the MC where I can throw some tubes in there to route them through the top of the reservoir. Anyone got advice on this as well?

I posted a picture below if that helps.

Thanks in advance!

IMG_8185.HEIC

[Marcarl]

First remove the hose at the bottom of the reservoir, you will need to reuse this hose because it is a formed hose so it doesn't kink. Then to the left bottom of the reservoir you can discover the bolt that hold it in  place. Remove the bolt and the reservoir will wiggle out. I don't understand what you are trying to do with more tubes to the top of the reservoir, so if needed maybe you could explain that as well. 

[TroyJackson]

Thanks so much for your help! That will steer me in the right direction.

And as far as tubes I just mean to bleed the MC. I’ve never bled one on a motorcycle, but normally for a car’s MC you route the brake fluid out of the cylinder with a tube you connect back into the reservoir and press the plunger a few times. 
 

Is there a different procedure for such a small Master cylinder?

Thanks again for your help. It’s very appreciated!

[Marcarl]

So the procedure: make sure the MC is clean and in good condition, as well as the reservoir. Put is all together and fill the reservoir with fluid. Crack open the banjo bolt on the MC until fluid comes out, and then close the banjo. Now bleed the rear caliper from air. You won't get any pedal yet. Now you need to get at the metering valve on the back of the triple tree and loosen a connection there. It's either the hard line or the flex line, which ever you can most easily get at. Now pump the brake pedal to get the fluid to come out. Close that back up and open up the bleeder screw on the left front caliper. I usually just pump the MC until fluid comes out and then close it. Now go back to the rear caliper and bleed as you normally would and then do the front left again. At this point there should be some pedal. Continue until all the air is out.

[TroyJackson]

Oh awesome! So I don’t need to remove the MC from the bike and bench bleed?

Edited June 23, 2023 by TroyJackson

[Marcarl]

Shouldn't have to, I never have.

[luvmy40]

It can take some time to get the new fluid through the lines. Don't give up and be sure to keep the reservoir full. I use a large basting syringe to fill it.

[cimmer]

Just a note..  there is a bleeder valve at the Triple Tree and after you do the above routines, you should bleed the rear, then the left front and then the triple tree bleeder as that is the highest point in the system and should be bleed last.  You could actually let the bike sit over night and bleed the triple tree bleeder to remove all the air..

I hope this helps.

Rick F.

[Marcarl]

16 minutes ago, cimmer said:

Just a note..  there is a bleeder valve at the Triple Tree and after you do the above routines, you should bleed the rear, then the left front and then the triple tree bleeder as that is the highest point in the system and should be bleed last.  You could actually let the bike sit over night and bleed the triple tree bleeder to remove all the air..

I hope this helps.

Rick F.

Not that I have seen all the 83s, but the ones I have worked on did not have such a bleeder valve, but I believe the 86 and up does.

[TroyJackson]

On 6/22/2023 at 7:15 PM, Marcarl said:

 

Hey Marcari! I havent had the time to follow these steps but just got started today! But I can't be more appreciative for all the help here!

Sorry to open up this thread again but a bit stuck because I may not have explained my original situation well enough.

There is DEFINITELY air in the MC. I know how to bleed brakes normally, but when I originally bought the bike the owner said the MC needed to be bled because air got in it.

So I followed your steps but the first problem I ran into was that fluid wasn't even making it to the rear caliper. Which is very strange because I tried to bleed them when I bought the bike and fluid was coming out of the rear caliper bleeder screw. Now nothing... I am kind of baffled to be honest. Everything is in it's right place and nothing changed other then me removing the MC and loosening the banjo bolt as per your instructions. The plunger is going into the MC and yet nothing is leaving the reservoir from what it seems!

So I guess my initial question may not have been clear enough. But is there a process for bleeding the MC? Not the Calipers and the lines but the actual MC. I see two bolts on the MC aside from the banjo bolts. Could these help release the air?

Usually a bit better at figuring this stuff out but don't want to create another issue for myself. So again, any help would be greatly appreciated!

Thanks in advance!

[Marcarl]

First off, the only way to get air out of the MC is through the banjos or the caliper. The other bolts hold the MC in place.

Procedure without seeing it, like right personal type thing kind of.
Make sure you have fluid in the reservoir and that the hose leading to the MC isn't kinked, this would assure you have fluid available for the MC. Next loosen off one or the other banjo bolts and then pump the MC slowly. You should get fluid in one or two pumps. Don't rush this,the fill hole in the MC isn't a pipeline. Once you have fluid proceed as per previous. If you don't get fluid, remove the reservoir and MC, first to make sure fluid gets to the MC and if that be the case to rebuild the MC, or just thoroughly give it a cleaning. In doing so, if you find that there is corrosion in the MC, rebuild it or replace it. New ones are not available from Yamaha but could be elsewhere.

Post back for more info,,, we don't mind one bit,,,, maybe 2 bits, but not 1 bit.