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Post by mouse on Jan 15, 2018 10:41:16 GMT 1
Dusty i spent a day on mine!! Drove me nuts!
In the end i called a very helpful mobile bike mechanic, who came and did it, let me know if you would like his number.
Mouse
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Post by dusty350 on Jan 15, 2018 12:23:17 GMT 1
Hi mate Cheers for that. I will keep at it for the mo - patience hasn't been exhausted yet !! Once I start throwing spanners I'll get help Dusty
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Deleted
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Post by Deleted on Jan 16, 2018 10:43:34 GMT 1
Hi It's a 14mm Nissin master cylinder, Dusty Is it stamped as 14mm. Pretty sure the std RGV should be stamped 5/8th (16mm). As an aside I put the lower output (1/2") master cylinder on std 350LC setup and it works brilliantly (like putting the 250LC Master cylinder on the 350LC set up). This works in completely the opposite direction you would expect it to work and goes from a wooden feel to nice and progressive with a firm lever
Why some master cylinders are marked in mm and others in fractions I have no idea
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Post by andy748 on Jan 16, 2018 11:42:53 GMT 1
Changed my Rgv calipers for Nissins off a Triumph, bled in moments! Downside is I’m using the refurbished Tokicos on my N1 hybrid with Rgv master cylinder, so I’ve got this to come. Go Nissin all day if you can get a cheap set. Andy.
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Post by rapidgaz on Jan 16, 2018 17:42:35 GMT 1
Have you sorted this now. If not use a big syringe and pump it from bleed nipple on calipers.
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Post by dusty350 on Jan 16, 2018 20:06:09 GMT 1
Hi No, still got problems. Was speaking to Yamark on the phone and we are now thinking the master cylinder may be faulty. If I leave the lever tied back overnight I do have some pressure by the morning, when I release it. If I then leave it all day there is no pressure by the time I come back to it, so wondering if the seal is knacked. Mark has kindly offered to pop over on Saturday to have a look. I will get a rebuild kit in the mean time so if Mark cant bleed it with his skills we'll try rebuilding the master. Dusty
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Post by Deleted on Jan 16, 2018 20:43:59 GMT 1
I can lend you a different master cylinder if that's any help
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Post by dusty350 on Jan 17, 2018 8:40:22 GMT 1
That's a kind offer, thank you I have got another Rgv master cylinder that I rebuilt but have not yet used - it's on the orange bike, so worst case scenario is I will use that, but hope to sort the issue with this one Cheers Dusty
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Post by looey on Jan 17, 2018 11:23:49 GMT 1
Hey Mr Dusty, I had this exact same problem with Tracey's R1-Z after I rebuilt the Calipers, I hadn't touched the master cylinder, so I knew there was nothing wrong with it. But..... it did turn out to be trapped air in the master cylinder. If you operated the brake lever in and out fairly quickly but only in as far as to just move the master cylinder piston a fraction, then tiny little air bubbles would come up out of the smaller return hole. Took about 2 hours of operating the lever like that and tapping the master cylinder gently occasionally and eventually the bubbles stopped and the brakes were absolutely perfect. Might not be this on yours but could be. Is the reservoir the remote type with a pipe, or an all-in-one metal unit ?. Probably more awkward with remote reservoir type I would've thought.
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Post by reggieperrin on Jan 17, 2018 14:24:32 GMT 1
Dusty, Don't leave the cap off overnight if you can help it. Brake fluid is hygroscopic and overnight is plenty long enough for it to absorb enough moisture to make it past its best, especially with damp air in the winter. Sounds like you're flushing it through pretty well at the moment though..! Good luck getting them right..
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Post by dusty350 on Jan 17, 2018 17:13:29 GMT 1
Hi fellas I keep trying the light tapping of the lever but as yet have not seen a single bubble !! I do put the master cylinder cap on at night - loosely, and I don't think the fluid is the problem. When I revamped the garage it became the hottest room in the house - it's often hotter than Death Valley in there, so no damp issues. The fact the master doesn't hold what little pressure I can generate may point to a dodgy seal, but Mark is certain he will be able to decide one way or he other once he has had a look. Just need to get a rebuild kit now. My master says 14mm which is obviously different to 5/8ths ?? Dusty
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Post by Yogi on Jan 17, 2018 17:40:02 GMT 1
Hi Dusty
I'd say it's definitely the master cylinder unfortunately 9/16ths is the closest imperial size to 14mm as you probably know
I rebuilt 2 masters and was getting the exact same symptoms as you Replaced it with a second hand one and it bled perfectly
Good luck Matt
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Post by dusty350 on Jan 17, 2018 18:55:31 GMT 1
Hi Matt Just had a closer look at both masters. My orange bike has a 5/8ths Nissin fitted and worked ok with the Tokicos on the bike originally. The White bike has a 14mm Nissin master fitted - looks identical to the other one but obviously different size internally. I think I will have to rob the master off the orange bike and fit it to the white bike and try again. Plus the 5/8ths master has had a rebuild in the past. Dusty
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Post by Deleted on Jan 17, 2018 20:55:57 GMT 1
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Post by dusty350 on Jan 17, 2018 21:29:24 GMT 1
That's an interesting link Gonna have to stick with a Nissin cylinder due to matching Titax levers and billet fluid pot. I'm hoping that changing the cylinders over will solve the problem. Fingers crossed Dusty
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Post by JonW on Jan 17, 2018 22:33:34 GMT 1
I do love radials, and run them on some of my bikes, but think youre heading the right way Dusty. If its not the master when you swap over then its just air still in there and you need to keep going, but from what youve said I think the 14mm needs a rebuild.
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Post by JonW on Jan 17, 2018 22:35:14 GMT 1
My master says 14mm which is obviously different to 5/8ths ?? Dusty Yes, 5/8" is 15.875mm
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Post by dusty350 on Jan 18, 2018 8:33:51 GMT 1
Just need to find out which Nissins use a 14mm bore. I think yzf750 but will have to double check. Dusty
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Post by JonW on Jan 18, 2018 10:32:07 GMT 1
I did know, a mate and I were gifted a set. I had the master and he had the calipers... but i forget which model now, sorry m8.
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Post by dusty350 on Jan 19, 2018 9:06:35 GMT 1
No worry Jon, I had a quick look on ebay and it shows quite a few bikes with the 14mm master, including Triumph. I found a link to a Triumph forum describing how to improve the brakes on a 955i by using a 16mm master off a Kawasaki instead of the 14mm Triumph item. I think my plan is to use the 5/8ths Nissin off my orange bike which I rebuilt but haven't used. Yamark is kindly gonna give me a hand so we'll make sure it's not an air issue with the 14mm first, but then I think I will fit the other master and source a second 5/8ths master for the orange bike at a later date. Hopefully by tomorrow I will have the bike ready for Mot, finally !! Thanks for all the replies fellas I will let you know how tomorrow goes Dusty
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Post by sbscnor on Jan 19, 2018 9:37:31 GMT 1
Dusty I used a ZXR750 Nissan with remote res, pretty sure its a 5/8th can have a look tonight if you want. I use twin 4 piston calipers and the brake has a good feel to it no problem bleeding it. Pity cannot say the same when I did my rear that was a right b*&^%ed to bleed up and it was a brand new under slung Brembo with a YPVS M\C fully rebuilt.
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Post by dusty350 on Jan 19, 2018 10:10:24 GMT 1
Hi Colin There seem to be lots of variations on the Nissins - they look the same at first glance but obviously differ internally - size wise. The underslung Brembo on the white bike is already done thankfully. I still have not got away with it though as I need to bleed the same set up on the orange bike I think the Vacuum bleeders really come into their own on systems like that. I'm not adverse to swapping parts between bikes and my focus now is to get the white Lc hybrid mot'd so I can register it and get it on the road. I think I'm gonna swap the wheels over too before I Mot it. Did a bit of photoshopping and I think the black wheels need to be in the orange bike. More work !! Cheers Dusty
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Post by sbscnor on Jan 19, 2018 11:28:25 GMT 1
Dusty , I tried a vacuum bleeder on the Brembo still no joy, I got a tip to try and get the caliper ABOVE the M\C. I unbolted it from the carrier raised it up as high as I could wedged a screwdriver between the pads bleed it manually and now the pedal is rock solid in fact it feels a bit wooden was hoping it improves with use.
I got my German bike MOT'd on 3rd Jan and sent documents to DVLA, they got the doc's on 4th and I got a V5C back on the 13 Jan. One word of warning there is a post on this forum on how to complete your V55\5 Application to register a vehicle they have changed the form since that post was created.
I have copies of my V55\5 (don't forget you need to request a V55\5 from DVLA it's not available from a PO or a download from DVLA) if you need to see what needs doing just drop me a pm if you need it.
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Post by dusty350 on Jan 19, 2018 11:40:51 GMT 1
Hi Colin Thanks for that info - that's gonna help. I know about Shauns post regards registration and was gonna follow that. The bike is ready for Mot once the brakes are sorted and I have the Nova and the German logbook so I'm hoping it will be fairly straightforward. If I need help I will give you a shout Cheers mate Regards Dusty
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Post by dusty350 on Jan 20, 2018 16:11:32 GMT 1
All hail Yamark - the brake God !! Mark kindly popped over to mine today to help me sort those pesky front brakes. After some checking, it was decided my existing front master cylinder was fubar - wont know why until I pull the piston but that's for another day. I had the master cylinder from the other bike ready to go so we bolted that on and then watched "the Yamaster" reverse bleed the system - none of that "cracking the bleed nipple on the calipers" rubbish !! Needless to say it was very satisfying seeing all the air bubbles return to the reservoir. The rear system got bled just for good measure. So now all the brakes work as they should. The rear Brembo is a bit weedy but as long as it passes the Mot it will be fine. Thanks again for your help today Mark - really appreciate it and hopefully the Mot is only a few days away ! Dusty
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Post by 0h5h1t on Jan 20, 2018 16:37:37 GMT 1
Thats good news Dusty mate!
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dbgr
Drag-strip hero
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Post by dbgr on Jan 20, 2018 16:38:25 GMT 1
dusty, was that not what I gave on the first reply..
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Post by dusty350 on Jan 20, 2018 16:50:57 GMT 1
Hi I had been trying that - reverse bleeding - but that only works if the master cylinder isn't knacked like mine. I wanted Mark to test my set up to see if he could rule out anything I had done wrong - second opinion !! Plus he has the 4 pot Tokicos on his triple so knows his way around that set up. With a working master, the reverse bleed worked a treat He's done far more brakes in the past than I have and he made light work of it !! Dusty
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Post by yamark on Jan 20, 2018 18:46:47 GMT 1
Dusty, your more than welcome mate. I know a large number of guys on here suggested exactly what I did - in many ways, you were all correct. Over the years I have bled and worked on more brakes than I care to remember. At Dusty's, I checked for air in the system by pumping the lever quickly and holding the lever with a bit of hand pressure; measured the lever to bar clearance, released the lever (to unpressurise the any air) apply the same hand pressure, and the lever moved closer to the handlebars. So a bit of air in the system. I felt at this point the master cylinder seals were not great, even if you pressurised the air the piston seals felt "weak", also if I released the brake lever quickly, I had no movement of fluid in the reservoir showing a problem with the return circuit.
We changed over the master cylinder like an F1 team as well as pair of surgeons! (we left the fluid in the system, just draining the reservoir). Then with the master cylinder angled up (full left lock), topped up the resy and reverse bled.
For those that don't know, this means just moving the brake lever a little to allow the air to escape. You occasionally do several mini pumps of the lever as well as a large full sweep of the lever every now and then and just let the air rise. You agitate the air and dislodge it using this method. Then I changed to right hand lock to remove air to the right of the piston, and once no air came out, back to full left lock. More reverse bleeding, more air. You know when your getting close (obviously the lever gets resistance), as loads of air comes up followed by a short stream of tiny bubbles. We then had good brake pressure, and the brakes lock the wheel with ease.
Apart from a faulty master, air in the system, or a leak, the only other hydraulic brake fault I've come across is corroded pistons/seals or seals stuck to pistons (if the bike is laid up for a long time). The piston seals flex and wont let the pistons slide - this fault feels like air in the system.
HTH someone
Great tea Dusty Go get that MOT
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Post by donkeychomp on Jan 20, 2018 22:11:24 GMT 1
Glad to hear it's all done now. You still taking the bike to Black Dog Dusty? MOT tester there loves a 2 stroke. His eyes will be out on stalks when he sees yours!
Alex
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