collapse

www.dimecitycycles.com

www.cognitomoto.com

https://www.townmoto.com/collections/vanson-leathers

www.speedmotoco.com

www.CITYLIMITMOTO.com

www.jadusmotorcycleparts.com

www.lostapostlejewelry.com

www.sparckmoto.com

www.pistonsociety.com


Author Topic: 1982 CB750F... The resto-not  (Read 33086 times)

Offline advCo

  • DTT BOTM WINNER
  • *
  • Posts: 3234
  • Nick Ol' Eye
    • adventur Studios
Re: 1982 CB750F... The resto-not
« Reply #500 on: Apr 09, 2019, 11:21:08 »
From what I've read, 5 is a silicone based brake fluid and has a higher boiling point than 3-4. Because it is silicon and not glycol based (like 3-4) it does not absorb water and reportedly does not ruin paint. People have been running it in older systems for years without problems. The only thing you'd have to worry about is if it eats the seals, which I would think would happen pretty quickly if it were going to.

https://www.thesamba.com/vw/forum/viewtopic.php?t=409242&highlight=dot5

Offline Jimbonaut

  • DTT BOTM WINNER
  • *
  • Posts: 1941
    • Lost Apostle
Re: 1982 CB750F... The resto-not
« Reply #501 on: Apr 09, 2019, 11:21:28 »
I've done a bit of research into the make-up and advantages and disadvantages of the different fluids so I now know a bit more about their application.  What I'm trying to understand is the first line of that link Mike - "Always refer to vehicle owner's manual for what the manufacturer recommends or warns against".  The manufacturer (Nissin) is recommending against DOT 5 (or says that DOT 5 is not compatible) but I'm trying to figure out why.
"I'm telling you Donnie, nuthin' but nuthin' but right"

Offline advCo

  • DTT BOTM WINNER
  • *
  • Posts: 3234
  • Nick Ol' Eye
    • adventur Studios
Re: 1982 CB750F... The resto-not
« Reply #502 on: Apr 09, 2019, 11:23:35 »
I've done a bit of research into the make-up and advantages and disadvantages of the different fluids so I now know a bit more about their application.  What I'm trying to understand is the first line of that link Mike - "Always refer to vehicle owner's manual for what the manufacturer recommends or warns against".  The manufacturer (Nissin) is recommending against DOT 5 (or says that DOT 5 is not compatible) but I'm trying to figure out why.

Jim, does it say "DOT 3 or 4 ONLY" or "DO NOT USE DOT 5"?

Like I said the only worry would be it eating seals, so maybe they know that the rubber they used isn't compatible with the silicone based fluid. But I've never heard of that happening before.

Offline Jimbonaut

  • DTT BOTM WINNER
  • *
  • Posts: 1941
    • Lost Apostle
Re: 1982 CB750F... The resto-not
« Reply #503 on: Apr 09, 2019, 11:26:03 »
The only thing you'd have to worry about is if it eats the seals, which I would think would happen pretty quickly if it were going to.
That's what I'm thinking - DOT 5 may bugger up the seals in the master cylinder.  Of course there's one way to find out, but the cylinder I'm eyeballing is not exactly cheap  :o

Would DOT 5 really attack the seals in a master cylinder?  Seems counter-intuitive that brake fluid would attack rubber seals in a brake system, bit of a design flaw, amiright?
"I'm telling you Donnie, nuthin' but nuthin' but right"

Offline advCo

  • DTT BOTM WINNER
  • *
  • Posts: 3234
  • Nick Ol' Eye
    • adventur Studios
Re: 1982 CB750F... The resto-not
« Reply #504 on: Apr 09, 2019, 11:32:09 »
That's what I'm thinking - DOT 5 may bugger up the seals in the master cylinder.  Of course there's one way to find out, but the cylinder I'm eyeballing is not exactly cheap  :o

Would DOT 5 really attack the seals in a master cylinder?  Seems counter-intuitive that brake fluid would attack rubber seals in a brake system, bit of a design flaw, amiright?

I honestly doubt it would, but that's the only potential issue I could see. I've never heard of it actually happening before. I would just put it in and go with it.

Offline doc_rot

  • DTT BOTM WINNER
  • *
  • DTT SUPPORTER
  • *
  • Posts: 1339
  • Oh the usual... I bowl, I drive around...
Re: 1982 CB750F... The resto-not
« Reply #505 on: Apr 09, 2019, 11:32:51 »
i think mastercylinders usually say don't use DOT 5 because is not compatible with DOT 3 & 4 and that is what they assume the system to have been bled with from the factory. if its a fresh system i think you're good to go.

Offline Maritime

  • DTT SUPPORTER
  • *
  • Posts: 9901
Re: 1982 CB750F... The resto-not
« Reply #506 on: Apr 09, 2019, 11:33:02 »
Did the bike it came off of have ABS originally, that would be why it would say no DOT 5.
The GL Rebirth: http://www.dotheton.com/forum/index.php?topic=68337.0
CX500 Low budget Bobber : http://www.dotheton.com/forum/index.php?topic=43617.0
"Beer makes you feel the way you ought to feel without beer" -Henry Lawson
"Beer is proof that God loves us and wants us to be happy." - Thomas Jefferson

Offline Jimbonaut

  • DTT BOTM WINNER
  • *
  • Posts: 1941
    • Lost Apostle
Re: 1982 CB750F... The resto-not
« Reply #507 on: Apr 09, 2019, 11:33:22 »
Jim, does it say "DOT 3 or 4 ONLY" or "DO NOT USE DOT 5"?

Like I said the only worry would be it eating seals, so maybe they know that the rubber they used isn't compatible with the silicone based fluid. But I've never heard of that happening before.
Good question - it depends what website I'm looking at.  The lid on the cylinder itself says "Use only DOT 4 from a sealed container" rah rah rah, and the item description (on some websites) says it's not compatible with DOT 5.  I'll be purchasing the cylinder from a different (cheaper!) site, but here's another link -

https://4into1.com/nissin-retro-master-cylinder-black-w-black-lever-5-8-piston/
"I'm telling you Donnie, nuthin' but nuthin' but right"

Offline Maritime

  • DTT SUPPORTER
  • *
  • Posts: 9901
Re: 1982 CB750F... The resto-not
« Reply #508 on: Apr 09, 2019, 11:44:37 »
Did the bike it came off of have ABS originally, that would be why it would say no DOT 5.

Just saw your link. it's new so that wouldn't be the issue. the article I linked said DOT 5 compresses different and reacts different so the piston design in this may be the issue, won't compress the same, to much i.e. instant lock, or to little, smooshy brakes or none at all. 

I doubt it's an issue with eating seals. or like Doc said, they are covering their butts assuming you have DOT3-4 already and you can't mix 5 in with that. It may be just fine if you have an all dry system to start and go 5. email 4-1 and see what they say to that.
« Last Edit: Apr 09, 2019, 11:46:34 by Maritime »
The GL Rebirth: http://www.dotheton.com/forum/index.php?topic=68337.0
CX500 Low budget Bobber : http://www.dotheton.com/forum/index.php?topic=43617.0
"Beer makes you feel the way you ought to feel without beer" -Henry Lawson
"Beer is proof that God loves us and wants us to be happy." - Thomas Jefferson

Offline advCo

  • DTT BOTM WINNER
  • *
  • Posts: 3234
  • Nick Ol' Eye
    • adventur Studios
Re: 1982 CB750F... The resto-not
« Reply #509 on: Apr 09, 2019, 11:58:51 »
I thought DOT5 was designed for use in ABS systems?

Anyways, if it says specifically on there that its "not compatible with DOT 5", then why risk it?

Product info on a master cylinder doesn't assume that you have DOT3/4 in your brake system. They don't care. If they say "not compatible with DOT 5," then theyre probably saying their internals either haven't been tested with DOT5 or have been tested and are not compatible.