Front Brake Problem!

[Ragin'81]

Ok, so the newbie is back with another question. The 74 CB750 I just bought did not have working front brakes when I bought it, so this is where I started with this project.
No brake fluid in the master cylinder so I put some in to see if it would work.
After letting it sit and pumping like a mad man I got pressure. I didnt notice any obvious leaks but the front brake now wouldn't disengage completely.
Ok cool.
Took it apart and found the caliper coated with old brake fluid. Wrestled to get the pads off and decided to obviously clean the caliper and the "caliper cylinder thingie" So I'm looking at this thing saying there has to be some sort of gasket to it but there wasnt one. Thats probably the reason for the leakage.
Does anyone know if theres supposed to be a gasket in there? If so where do I find one?

[Rodgil]

As well as the diagrams and advice in the workshop manual on this website, have a look at www.powersedge.com and www.mrcycles.com for exploded parts drawings, and Honda part numbers which will help you search for parts. You can then Google the part number, or search Ebay.

[TOOLS1]

They do not have a gasket, so to speak. All they have is the rubber O-ring that fits in the grove, and seals against the piston. These O-rings hardly ever go bad. I have never had to replace one. I just clean, and reuse them. Also just clean the inside, of the caliper with a Scotchbrite pad. Do not hone it!
If after, you reassemble everything it still will not disengage open the bleeder. If it disengages then your problem is in the master cylinder. Sometimes the hole that releases the fluid back into the reservoir will become clogged.  
TOOLS

[Re-run]

Make sure to clean that oring groove well. I dremel with a brass wheel does wonders without scraping things up. I did mine years ago and was shocked and amazed at what came out. Or use the scotchbrite pad but you have to pay very special attention to the sides of the groove.

Bikebandit.com also have a good exploded parts view too.

[Ragin'81]

Well Thanks guys, I found the part no problem at MRcycles! Appreciate all your help, Im gonna start cleaning it up right now. Then give em a new paint job. Any suggestions on paint? Anything paint you guys use thats holds up well?

[TOOLS1]

I like the ceramic caliper paint. I get it at O'Rileys. I would recommend, you flush out the system with alcohol, and use synthetic break fluid.  
TOOLS

[Re-run]

I use synthetic dot4 fluid. Been working good for quite a while now.
I also got a braided line from helusa.com It was awesome quality and I was able to get the line and fittings in what ever color I wanted, well to an extent.
I used regular spray paint on mine and it worked ok, just be a little more careful. It allowed me to be cheap.

[Lucky 1]

Synthetic brake fluid is silicone based. Purple color.
IT is DOT 5 .

DOT 3&4 brake fluid (yellow) is used in modern cars and is interchangeable.
IT is a hydraulic fluid.

Harley Davidson switched to DOT 5 fluid and now it has switched back to DOT 4.

The DOT 5 (silicone) could take more heat and not absorb moisture but
there must have been a reason HD switched back to DOT 4.
Maybe owners of HD's could not get the DOT 5 in some remote areas? Don't know.

That would require a call to HD corporate, and you know that is at least a 2 hour
investigation just to get to the right person.

[Piute]

You guys are great 750s...? are too..Just pulled my calipers fer paint,I've been using Engine heat paint,for all my BLK ,has a satin look ,leave gloss fer the stand out stuff,tank covers,fenders and thats better then gloss with more durability I believe,I HAVE A ..???...wasn't there a brake fluid that was made of fish oil it didn't eat paint ?

[Re-run]

Once you go to dot5, you cannot go back without a complete cleaning and line replacement. The silicone does not play well. Which is why I used a synthetic dot4.