New Reproduction Sandcast Brake Hoses

[Steve Swan]

If i were going to make it a rider, i'd use 'em.  VERY SUPER COOL period accessory.    

If i were going to enter the bike in a show competing against other sandcasts, i would have to take it off.  Like's already been mentioned, it's a bolt on accessory, the only messy part is dealing with brake fluid, if the RH unit was removed.

The only other factor to consider, the CB750 has remarkable oversteer, so the added front wheel weight will really add more to an already heavy steering.

The dual disc setup is a post sandcast update.  So, in theory, back in the day, it's most likely the lower RH brake line would have been a long neck.  Considering the short period of time the early vins fitted short neck lines, it's fairly unlikely short neck lines were ever available over the dealer's parts counter to be fitted for the RH caliper setup.

[Wayne]

You are correct Steve, left hose is short crimp, right is an over the counter. Obviously no "8" bolts on the accessory either so there's no such thing as "correct" with it. I figure it has history. I'll restore it anyway and decide down the road whether or not to install it.

On the topic of brake fluid, I know a lot of you don't put any in as the bikes don't run, but for those who do is anyone using DOT 5? Being that everything is new in the system we should be able to get away with it? I like the idea.

DOT 5 brake fluid is a silicone base, it does not absorb water, it will not corrode the brake system components. Ideal for vehicles which remain for a long time immobilized (collection and exhibition cars).
Unique dry and wet boiling point 260°C (500°F)
Military spec: MIL-B-46176
Meets or Exceeds FMVSS No. 116.

Save those nice new hoses you got from KP! 

[kp]

I'm using DOT 5

[hondasan]

I have been using DOT 5 silicon fluid for more than 20 years now in all my Hondas, from the sandcasts right up to a 2004 CB1300. Advantages as stated are that it does not damage paint if spilt or leaked, and does not absorb water.#5298 has done near 100,000 miles now since I fitted DOT 5. I never ceases to amaze me just how CLEAN that fluid remains over many many years and miles of use.
Personally, I will never use anything else.

Cheers - Chris R.

[Wayne]

Chris
If I'm not mistaken you can only add it to a "New" system. That means new hoses, seals etc. Draining and flushing old fluid an filling with DOT5 does not cut it, correct? Cross contamination will occur from even trace amounts left on seals etc. after flushing?

[markb]

Chris
If I'm not mistaken you can only add it to a "New" system. That means new hoses, seals etc. Draining and flushing old fluid an filling with DOT5 does not cut it, correct? Cross contamination will occur from even trace amounts left on seals etc. after flushing?

Good question.  I have one more, with all those advantages of silicone-based brake fluid, are there any disadvantages?

[Wayne]

Mark
To my knowledge there are no disadvantages to DOT 5 other than you cannot blend, or top up with any other fluid.

[Steve Swan]

That's a drag.........  I'd love to use Dot 5 in 232 & 4363.  

When i put 4363 into storage, I purged the system of the Dot 4 fluid.  So, i am guessing using Dot 5 is a "NO NO?"  

232 has never had brake fluid in it, i did put a film of Dot 4 from my finger tip to assemble the master cyl and caliper.  Think i could get away with filling w/ Dot 5 ??  

[Wayne]

Steve
I have read where people do change over to DOT 5. If you already have fluid in a bike you need to drain it and flush thoroughly with rubbing alcohol. I'm talking bottles of the stuff. The system needs to be super clean and then you have to get all of the alcohol out. The jury seems to be out on whether the process is good or not. This is my understanding of why:

Any remaining DOT 3 or 4 will cause a goopy substance to form were it contacts the DOT 5. The jury is out on whether or not the substance is compromises the integrity of the hydraulic system. So where you put DOT 4 to assemble the master and caliper you would probably get the "reaction" if it were not removed. (some say by "removed" you would install a new seal, some say clean it)

I'm no expert but I did do some research a while back when I changed the master (chrome of course  ) on my Harley. I concluded it wasn't worth the hassle unless everything were virgin in the brake system top to bottom.

[nmbr12]

Chris has it right!    Dot 5 is less likely to absorb moisture;Its the Right Stuff for yer Pampered ,not to be contaminated,Special Vehicles ..._Tim

[Wayne]

Read this on the net and thought it was pretty funny. They always have to get a jab in on the MoCo! 

IIRC, DOT 5 was developed by the military for use in hydraulics for tanks and such that sit around for years between wars... Harley-Davidson uses it, too; possibly for the same reason!

[hondasan]

Should of added that of course it should never be mixed with DOT 4, 3, etc, simply 'cos that would not be "best practice" - No idea whether the mixture would become harmful / no use as a brake fluid though.
 
No issues with using DOT 5 when rebuilding from scratch as everything is clean anyway.
With older "used" systems, I always start by dismantling the master cylinder and caliper in order to clean them out (essential anyway to get rid of the years of accumulated sludge), then re-build and bleed which will flush through the hoses. Suspect that this way even old sytems are better than 99% purged of the old.

I have never been tempted though to simply try bleeding DOT 5 through an old sytem without dismantling, as I can't see how you could ever be sure to have got all of the old fluid, or flushing liquid out.

I have bikes that it has been in for more than 10 years now, some of which have sat for most of that time - no caliper leaks, sticking brakes, or paint missing from fuel tanks where master cylinders have leaked!

I think Steve, that if all you did was to wipe the seals with DOT 4, that the system in #232 would be better preserved if filled with DOT 5 now. The small number of molecules of DOT 4 will likely sit in suspension in the DOT 5, and may even be bled out.

Cheers - Chris R

[Steve Swan]

Has anyone else received their lines from KP ?

If Honda were producing these short neck lines, they certainly would pass for new manufacture oem.

Thank you KP for taking your time and effort to produce such fine parts ! 

[cb7504]

Steve:
         I have not as of yet received my order of brake hoses, hopefully next week. Marty K.

[kp]

Should all be arriving soon. I think Chris R has received his KP