1980 XJ650G Maxim Brake Master Cylinder

Just thought I'd pass along this picture of the goo I found inside my Maxim's MC. It wasn't leaking, but I may rebuild it...

 

That's not a good sign!
You'll have to withdraw the Piston and Seals to look for possible pitting on the surface of the Bore.

Order a Kit.
Give that Master a complete overhaul.

 

that looks like long ago it was alive

 

While you are at it, replace the dingy window with a new one from Chacal. Being able to see the fluid is comforting.

The MC rebuild is simple compared to tearing down a rack of carbs. Its one of the easier systems to learn in my opinion and the results of a rebuilt front brake are amazing since many of these bikes are never properly maintained.

Get a speed bleeder. It makes the job of getting the bubbles out quite simple.

 

Polock, RickCo thinks I should rebuild it, but I really value your opinion; flush it out with clean fluid and it should be fine right?

 

What you "Should" do, ... is:

Rebuild the Master
Replace the Brake Lines (Stainless wrapped)
Overhaul the Caliper(s)
De-Glaze the Rotors

25 -or- 30 years is well beyond the service life of those component parts.

 

That sludge is covering a relief passage way at the bottom of the MC reservoir that is essential for operation. You have to remove all of the sludge and verify that the passage way is open and operational.

Your life is at stake. Do not skimp on time or effort when working on your master cylinder.

Gamuru wrote a nice article on rebuilding the MC.

 

first stab that thing to make sure it's dead.
then you might as well take the calipers apart too and cook the bunch of them in some real hot soapy water for a few hours, then see what you got

 

You should overhaul the calipers...if the MC looks like that you can be sure there will be some nasties at the other end...Polock, don't you recognize caviar when you see it :lol: Oh and Rick Co your state made the news here...that snow looks nasty!

 

For those who weren't sure, the above statement from my original post was sarcasm. Of course I will be rebuilding that master cylinder. I'm refurbing a 32 year old motorcycle, the brake master cylinder would get rebuilt no matter how good it it looked (it does look tasty).

And RickCo, please don't talk to me about stainless steel brake lines; as a moderator, you should know I'm not allowed to discuss them.

 

Stainless-wrapped Brake Lines are openly discussed and highly recommended.

The Kit I acquired from JX4Ever improved my Maxims braking considerably.

 

Hi RickB, now I am really concerned about the SS brake lines conspiracy.

I know they have been pushed and promoted, and of course, Len sells them. But your comment rings of some hushhush rule that makes me think it's all BS and maybe I can stick with my old rubbers?




P.S. appreciate the satire. Yours was not missed by me

 

Thanks Dan; "openly discussed" indeed...

 

Dan, stainless lines ain't no b s. i'll be putting them on my '06 sv1000s this winter and getting one for the clutch too, they're that much better.

 

Ah, Polock. They've gotten to you, too!

Are there any holdouts left, or has the resistance truly fallen?!

Damn you, Bilderberg group!

Soylent Green is made of dead people!

 

Sounds like we all agree that stainless steel lines are a good upgrade, but here's a question for the experts: do they really last forever? My stainless steel lines are about 20 years old, look and work fine, and the brake system has been well maintained for the life of the bike. But it's due for another brake rebuild (about 10yrs since the last one) and I'm wondering if I should replace the stainless steel lines.
Thoughts? What is the recommended lifespan for stainless lines?

 

The problem with ANY brake line, whether the original rubber-clad ones or stainless-sheathed lines, is the inner line, not what's on the outside.

The original inner lines that Yamaha used would eventually deteriorate from having fluid in them (or not) for years, dry out, then split or crack when flexed or at the fittings.

Hopefully, newer aftermarket lines are manufactured with better-quality inner lines that don't have as short a lifespan.

I think the true answer to your question could only come from the manufacturer of your replacement lines. Twenty years might be "past service life" or they could be fine if they've always had clean fluid in them.

I'd lean toward replacement.

 

I'm leaning the same way, bigfitz. At the time they were meant to last 'forever' but after 20 years you have to wonder about what the inner lines are like.

 

Aha! The truth is becoming transparent!

The revolution begins, and will be viewed on this forum!


Even so, I'll probably get SS lines onto my 650 this spring.