New Chinese Masters....

[kcoop99]

So I bought these on Ebay a few months ago and they were on the slow boat so I just received them the other day:
http://www.ebay.com/itm/18211993981...49&var=483496202556&ssPageName=STRK:MEBIDX:IT

They bolt up great and I have attached pictures of them. They only thing shady to me is the hole for the reservoir seems to be "punched" and not drilled.

I am seeming to have an issue getting the brakes to firm up. I can get the lever to firm up halfway back but if I pull hard I can get it to the grip. I seem to remember that I could not do that with the stock ones.

Any suggestions or comments on these? I believe the bore size is big enough. Thanks!

 

[Itgoes]

My only comment is that if they don't work......you're only out 39 bucks!

 

[Traumahawk]

Is there any possibility there there is still in the system?

 

[kcoop99]

That's true! I just wish I could get it to firm up better! I even tried the MightyVac!

 

[Traumahawk]

There are some people here that have had GREAT luck using a reverse bleed. Getting a large syringe, and pushing fluid up from the bleed valve into the MC.

 

[42Below]

Another trick is a rubber band on the lever for a day or two. It can let some air back up.

Its a heck of a place to use cheap parts though. You are braver than me. Can you get stock parts coated or polished?

 

[[email protected]]

Might just need to bleed it some more.
Any signs of leaking on the calipers?

What is the bore size on the master you purchased? If too small, you may never get the brakes to firm up due to lack of fluid movement to pressurize the entire system. Anything smaller than 14mm would be a problem.

If the bore is too large the lever would be very firm, very fast. Too small and just the opposite.

Its also possible that its a faulty part or manufacturing flaw. Maybe some casting flash or debris stuck in the system somewhere.

 

[one2dmax]

If you can check the bore size it will tell you a lot about it. We tried a similar setup from China and the bores were too small to work right. Ended up drilling out the bore and swapping in some vmax guts which actually worked. The clutch was a bit wonky but still worked though not as well as the original.

 

[caseyjones955]

The Chinese stuff always looks great in the pics and the prices are really hard to beat but Ive had pretty shitty luck with stuff from over on that rock. Like Sean said, measure the bore and see if its right, if so further bleeding, I hope it works. It was sort of expensive for me to learn not to order from China or anything Chinese from "USA sellers". That is to bad because I think that master looks really cool.

 

[SpecOps13]

Chinese CRAP!!! I HATE IT..

 

[Fire-medic]

Sounds like this is a case of, you get what you pay-for. :confused2::damn angry:

If you look on the forum and use the search function, you can find lots of time and effort has been put-into finding-out what size bore will work, and what years and models of other bikes' master cyl's will swap-in, with good results. There is a chart about the effect of using how-many pistons in a caliper to achieve the 'sweet-spot' of juice being moved and the 'feel' of the brakes. I know the pretty stuff looks like it should be an upgrade, but in the instance of your life depending upon your brakes' function, and being able to make the clutch work correctly, this really isn't anyplace to experiment.

Use the search function here and find knowledge others have already gained about swapping master cyl's. Here is one such post, I saved you on this one: http://www.vmaxforum.net/showthread.php?t=17036&highlight=master+cylinder+bore+chart

Another: http://www.vmaxforum.net/showthread.php?t=38890&highlight=master+cylinder+bore+chart

 

[kcoop99]

Sounds like this is a case of, you get what you pay-for. :confused2::damn angry:

If you look on the forum and use the search function, you can find lots of time and effort has been put-into finding-out what size bore will work, and what years and models of other bikes' master cyl's will swap-in, with good results. There is a chart about the effect of using how-many pistons in a caliper to achieve the 'sweet-spot' of juice being moved and the 'feel' of the brakes. I know the pretty stuff looks like it should be an upgrade, but in the instance of your life depending upon your brakes' function, and being able to make the clutch work correctly, this really isn't anyplace to experiment.

Use the search function here and find knowledge others have already gained about swapping master cyl's. Here is one such post, I saved you on this one: http://www.vmaxforum.net/showthread.php?t=17036&highlight=master+cylinder+bore+chart

Another: http://www.vmaxforum.net/showthread.php?t=38890&highlight=master+cylinder+bore+chart

Sorry, when searching (endlessly) I did not find quite what I was looking for thus creating a new thread.
I will take your answer as a "no they will not work". Thank you.

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[Fire-medic]

From the ad on ebay: 14mm Bore Motorcycle Brake Lever Master Cylinder

14 mm is smaller than the VMax 5/8" bore. The 5/8" bore is 13+% > the 14 mm of what you are using. Less fluid moved per stroke distance will (please correct me if I'm wrong) require more lever travel to get the same volume of 'juice' to create pressure on the caliper pistons. Thus, the lever would travel further back towards the handlebar to generate a similar effect at the calipers.

I prefer to have a firm lever by 1/2 travel, where the lever won't come back to the bar any further. As was suggested, I think you need to try reverse-bleeding the slave cylinder bleeder valve, because that will help to push-upwards any residual air bubbles.

If you're careful to gently squeeze the lever when you have the stock reservoir cover off, you will see a small solid geyser of brake fluid squirt up from the master cyl hole in the floor of the reservoir, when they are properly-bled. Since these Chinese items appear to be 'radial' style, you won't be able to see that. There is only the one reservoir hole.

Here is some info on the reverse bleed, which I've found to be quicker than using a MityVac. http://www.vmaxforum.net/showthread.php?t=31061&highlight=reverse-bleed

I strongly suggest you give that a try and see if your clutch action begins to give you resistance quickly, as it should, if you're properly-bled. On the stock handlebar mount and master cyl, I get about 1/4" space between the lever and the perch before I get good resistance. The clutch fully-releases well-before the lever is back to the handlebar, and on the front brake side, the brakes are locked-on at about 1/2 of the total distance to the handlebar.

Sorry, when searching (endlessly) I did not find quite what I was looking for thus creating a new thread.
I will take your answer as a "no they will not work". Thank you.

Sent from my SM-G930V using Tapatalk

 

[kcoop99]

From the ad on ebay: 14mm Bore Motorcycle Brake Lever Master Cylinder

14 mm is smaller than the VMax 5/8" bore. The 5/8" bore is 13+% > the 14 mm of what you are using. Less fluid moved per stroke distance will (please correct me if I'm wrong) require more lever travel to get the same volume of 'juice' to create pressure on the caliper pistons. Thus, the lever would travel further back towards the handlebar to generate a similar effect at the calipers.

I prefer to have a firm lever by 1/2 travel, where the lever won't come back to the bar any further. As was suggested, I think you need to try reverse-bleeding the slave cylinder bleeder valve, because that will help to push-upwards any residual air bubbles.

If you're careful to gently squeeze the lever when you have the stock reservoir cover off, you will see a small solid geyser of brake fluid squirt up from the master cyl hole in the floor of the reservoir, when they are properly-bled. Since these Chinese items appear to be 'radial' style, you won't be able to see that. There is only the one reservoir hole.

Here is some info on the reverse bleed, which I've found to be quicker than using a MityVac. http://www.vmaxforum.net/showthread.php?t=31061&highlight=reverse-bleed

I strongly suggest you give that a try and see if your clutch action begins to give you resistance quickly, as it should, if you're properly-bled. On the stock handlebar mount and master cyl, I get about 1/4" space between the lever and the perch before I get good resistance. The clutch fully-releases well-before the lever is back to the handlebar, and on the front brake side, the brakes are locked-on at about 1/2 of the total distance to the handlebar.

Thank you!! Awesome info. I messed around with them tonight and don't think they will work. Reverse bled and regular bled. Same lever travel...

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[gentsvmax]

Too bad ,they look kinda cool

 

[caseyjones955]

Too bad ,they look kinda cool

+1, they do look cool. Im sorry they wont work.

 

[wildweasel_pt]

My only comment is that if they don't work......you're only out 39 bucks!

Out 39 bucks and maybe dead on top of that.

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[kcoop99]

Alright alright guys!! Lol! I'm taking them off!! Geesh!
I will admit that I was apprehensive about putting them on. Good thing they won't work!

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[Fire-medic]

If you read the threads in entirety I posted, you will find info on masters from other bikes which do work w/the calipers we have, or ones commonly-mounted in-place of the stockers, such-as the FZR1000 six-piston ones, or the early R1 calipers (not radial mount calipers from the later-model R1's. Unfortunately, those choices are only for the 1993-up bikes, the 1985-1992 models (yours) have a different mounting bolt spacing for the calipers I mentioned, which have a 100 mm o.c. spacing. They also require the 298 mm dia. rotors from the 1993-up VMax models.

Sean Morley does offer a single-sided Suzuki sportbike caliper & rotor setup for the early bikes that the users who have it are happy with the setup. He can probably suggest what matching master cylinders would provide you with adjustable levers, and which may be available from the bike 'breakers' as our British friends refer to used parts entrepreneurs.

 

[maleko89]

He has Busa calipers already on the bike.


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