Modding my V4 for a right hand only rider

yea i saw that ... mine is a psc16 .. i think finding seals or even a rebuild kit is going to prove really hard..
but i found the culprit, it turns out the front seal on the piston has a small tear, it was under the backing washer so i could not see it. but thats where the pressure was going,
i thought about swapping the rear seal to the front and it would work but with the rear seal torn, as soon as the front seal went bad which cant to far away the rear seal will leak the oil and piss all
over the paint and everything else so thats a no go..

i did polish the bore of the master and its flawless, it took 5 seconds with a cloth on a wood dowel and drill..with some flitz on the towel.. .it literally took 5 to 6 seconds on slow speed and all the rust and
what looked like scarring is gone.. but no point with out a seal or rebuild kit,
im gonna keep looking for a psc16 rebuild kit .. if not my other options are a new psc15 or psc16 brake master, i just wish i had spare parts for when these things go bad down the road you know
ill give em a call and see if maybe they have a psc16 rebuild kit

Are there any part numbers embossed onto your master? For search purposes...

so i have been looking at the ps16 vs psc16 rebuild kit... the ps16 is the black version of the gold 16mm axial master that came on the old ducs.. the ps16 piston looks exactly like the one i took out of my psc16..i think im gonna give ot a shot. at 49 bucks its worth the gamble

so the piston i found om ebay and gotham cycles is actually for the early pr16 radial master.. it looks identical in pics to my psc16 piston. i have contacted. gotham cycles to see if they can take some dimensions and more detailed pics.. if not its gonna be a new one.. i really want spare parts though you know we dont always get what we want i guess

Sutki said:

Thanks y replay.
I guess, need to use you way also.

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bp_SFV4 said:

Are there any part numbers embossed onto your master? For search purposes...

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i actually tried all of the numbers i found embssed on it, and i got no hits on either of the two it ,ay have been a ducati part number since they are ducati masters

I've ordered from Gotham Cycles in the past; they've been great. Maybe reach out and tell them what you're trying to do. They might have a solution.

they got back to me ad told me there are no more rebuild kits for the psc16 as they are very old ...only thing left is the new units still left in stock..
im gonna explain my situation to them and maybe they might be able to take a few minutes to take some measurements to see if i can use that piston,
if so i will buy 3 or 4 them. that should be more than enough for me, but from now on i will only use new masters if possible
im gonna do a cad drawing of my piston with dimensions and see if maybe they have someone who can take a few minutes to take just 2 or 3 measurements
and i will know for sure if i can use it. but it looks like thats the one.
plus the rs16 radial, i think was the first radial after the axials were replaced by radials..so it would sand to reason that possibly some of those parts would be reused
in the first gen of the radial family. ...
fingers crossed, this is my constant struggle.
i spoke with the guys who have the dual master cylinder on the isle of man and the price is 1500.00 US ... ouch...
this is a constant struggle. but had i used a new master instead of a used this would not have happened. i was just not aware that there was NOS psc16 still in circulation.
fingers crossed

ok so i was too excited.. and jumped the gun.. the piston is not the same but the seals are for a 16mm bore.. so i took a chance and found a shop in the uk and bought 4 repair kits.. if the piston small diameter is the same..and im betting it is. i can easily remove the front seal by removing the C clip..but the rear seal is captive and was stretched onto the piston at the factory so i will have to find a way to remove it without ruining it or put the piston in the lathe and carefully cut the back flange off so the seal slides off then get ot back on my piston without splitting it. im hoping they are still pliable enough to stretch and not split.. because its a really big strecth tp get the seal over the 16mm potion of the piston body. so i wait for parts now, if not i will pass them on to my brothers here for free who have PS16 radials. and again if this dont work, i just buy a new one. i know people will say just buy a new one already dammit. i just want to have spare parts so that when this happens again i can quickly fix it instead of going through this again. and the v4 most certainly will not be the only bike i own that uses psc16 masters and psc16 masters are the only ones i can use..so its a bit of a vicious cycle.

the rebuild kits for the pr16 showed up today and i was too excited to wait for it too cool down so i went to it..
and damn did i get lucky.. most folks would see these parts as a lose..but to me its a goldmine.

ok guys, i have ....... had it with the ...... spongy feel of the front brake. i have tried 3 masters 1 new u ysed and rebuilt and a new radial master, all feel like ...., the initial squeeze is just ....... IMHO. i have raced cmra and have more trackdays than i care to admit to paying for and never have i had a brake lever that feels this ....... im just fed up with it, it does not belong on a bike of this caliber. but all of the other bikes i have ridden and raced did not have abs.

so do i just need to delete the abs to get rid of .... spongy feel
i have bled, rebled, bled rebled.. i have tired lever first then calipers and backwards and forwards, and have cracked the banjos and bled at the abs pump fittings tried got 2 dot 3 dot1000 synthetic non synthetic. im absolutely out of ideas.
some of the sponginess goes away after rebleeding but i is stil shiiitttttt.. IMO
who has had this experience before and did deleting the abs fix it.
i like a brake lever that hits a solid wall, i like the feel feedback and the braking threshold i get from that, some dont like it that way, i do.
i know how the braking feel and ratio of changing from an 18 to a 16mm master changes things, but once the system is bled and there is no air, the initial wall that the lever hits should be the same. not accounting for abs pump if thats causing the problem. i het why abs but i dont need it, not on the street not on the track. so it thats the problem ill toss it

dammit guys.. i fell victim again to the IF ITS NEW ITS PROBABLY NOT THE PROBLEM. the damn new master cylinder i bought.. before i deleted the abs i thought, ill swap the clutc hand brake master cylinder.. so the clutch master i rebuilt is now the brake master..and ill be dipped in ....... it did not immediately fix the problem..its not that rock solid wall feel that i like but its 95 percent of it compare to what was 60 percent of it before. the vids shows my findings and they kinda suck for a new brembo product....so i know from know on,,new or used, tear it down and check..hone bore if necessary,,

this shows what the video couldnt focus in on
this may not be usable even as a clutch master cuz it will eventually cause a seal failure and ill lose the clutch like last time

Your last video just popped up in my YouTube feed. It looks like you'd have to take a lot of material out of it to get it smooth.

yea, thats what im afraid of and the reason that i thought i might not be able to use it, the scars came out faster than it thought.
after measuring the whole bore before and after it has evenly grown by .0013 inch, not too bad.
when talkin about a small bore and seal it may as well be the grand canyon but , im gonna put it back together and see if it seals, if not ill buy another master and check it before using..
, i wont waste a new seal set on this master if the bore is to jacked up to seal, and ill just use it for parts
it will never be a brake master cylinder as i will never trust my front brakes with it, the consequences are to high
ill report back if it seals or not

IM CALLING NO JOY.. even though the scars are not visible they are still there.. i found that the steel shim that sits behind the seal was too large OD.. and was razor sharp from the stamping process.. this shim is what scarred the bore up.. even though the scars are shiny and almost indistinguishable from the rest pf the bore, they are still there i can feel them with a plastic pick.. so they are too deep.. what is happening is that as the edge of the seal slides past and over the scars..the scars fall into the empty air pocket between the seals so the scars kind of fill with air then the seal ride back over the scars on the return trip and that trapped air ends up inside the oil section. so as we were trying to bleed it... a whole liters worth the small almost to small to see bubbles just kept coming.. so im going to buy a new one and a used one..hopefully 1 if not both will be useable and or rebuildable.

Can you sleeve it?

we think alike... i thought about that..but to be honest by the time i got it done... all for just buying a new one AGAIN for 124.00 i would be way over that just in the amount of hours,, not counting the smaller tooling i would have to buy to work such a small bore properly..
so i just bought as new from a different retailer than last time hoping to maybe get away from a possible bad batch.. and i purchased a used one as well if the new is good i use that one.. and the used one i can use the body to rebuild the bad one i have now.
at 124 for a new one i just could justify the amount of work.

Yeah, for that much it’s not likely worth the effort if they’re still available.

i found some in japan.. LOL.. thought id give that a shot

so the new master came in...and before i even messed with the lever, i took it apart to inspect the bore for damage and it was spotless..so it put together and buttoned up, but would you believe this ...... the air stopped coming from the master... the lever feel has improved
but is still very soft in my opinion and it still pumps up when i quickly pump the lever which means there is still air in there. i recycled new 2 liters through it while bleeding over and over and over and its still not anywhere as good as the old 748 master cylinder i rebuilt after the failure of the seal...the old 748 master is way more stiff with 95 percent less soft than the new one. so its not an air in the system problem..its a master cylinder problem..
i have examined them both and i cannot find a design difference and . the seals and pistons are identical, so i swapped them again.. and the old 748 master is far superior to the new one.. im not sure how or why.. but im gonna leave it since the master is better than the last one..the feel of it dd improve on the initial hit where the other was so soft on the first hit it was a bit scary.... but since these brakes have so much power it still works extremely well.. im thinking about trying the EPFA pads

but there is no more air coming out of the master when i bleed no air from calipers..massive brake power, its just not the way i like it. but we dont always get what we want..if i really cant live with it i will swap the clutch and brake master..
but im callin this one done, it just really infuriates me that the new master cylinder did not immediately act like the old rebuild supposedly identical 748 master...something is different in the design but i cannot find it. on thing i could think was maybe the durometer of the front piston is harder on the pr16 rebuild kit (which i used to rebuild the 748 psc16 master ) and the new old stock psc16 has softer seals in it.

1hander said:

but is still very soft in my opinion and it still pumps up when i quickly pump the lever

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I don't think that's too terribly different from the OEM Panigale V4 front master cylinder and is a big reason why guys switch to the RCS 17. The OEM master certainly has a lot of stopping power. My last track day I managed a stoppie at the end of the straight. I just kept pulling more and more and it gave more and more. I would prefer a more direct lever to braking force feel and have been thinking about upgrading. I'm also wondering if a RCS clutch master would make launching it easier.

Have you considered injecting fluid from the calipers up to the master to remove air?