How can I get these disk brakes working again?

[m511y]

My xs750 build has gotten to the point where I need to sort out the brake calipers, lines, and reservoir. The bike hasn't run since the early 1990s. The brake resevoir was 100% dry and had what now looks like flakes of couscous in it.

What should I use to clean all of this gunk out and can I salvage the lines? I haven't taken apart the pistons yet to examin the seals and if there is pitting. I'll probably get to that after work tonight.

Could I boil these parts in distilled water and lemon juice like I have done with my carbs?

Any advice is greatly appreciated.

 

[Sonreir]

Depending on the amount of gunk, you'll probably want to rebuild the calipers and master cylinder. If you can't get the gunk out with methanol, you can try a weak acid (Coca Cola is a decent choice, seriously) and then lots of flushing with water and another flushing with denatured alcohol.

The lines should be replaced rather than cleaned.

 

[Bert Jan]

To save a lot of hassle, get yourself a new master, new lines and a rebuild kit for the caliper.

 

[m511y]

To save a lot of hassle, get yourself a new master, new lines and a rebuild kit for the caliper.

I'm comfortable with hassle, What I would like to save is money.

 

[VonYinzer]

As Sonreir stated, DO NOT REUSE 20 YEAR OLD BRAKE LINES. Spend the money for new ones. Your life is worth a few bucks.

 

[Hoosier Daddy]

Mikes XS has some damn good prices, almost makes me wish I had a Yammy.

 

[Bert Jan]

As Sonreir stated, DO NOT REUSE 20 YEAR OLD BRAKE LINES. Spend the money for new ones. Your life is worth a few bucks.

that.

furthermore, a good rebuild kit will be as much a good used master. search eBay and such, they go from $20 up. Problem i find with master rebuild kits is that they never work very well. Always trouble with installing, leaking and shit.

 

[darkhorse]

Rebuild the calipers! Mixes XS has seals and stainless steel pistons. Getting the old pistons out can be a challenge. I was able to hook a rubber tube up to the bleeder valve and pump them out with a bike pump. You can also pump them out with a grease gun, just be carful they come out like a canon ball!

 

[jackseattle]

Having just been through this drill with my cb400f, your $$ and time are probably best spent on cleaning and rebuilding the brake caliper and its pistons. Buy new brake lines and -- if you can find them-- phenolic caliper pistons (check Godffrey's Garage) instead of the s/s pistons. Bert Jan is right, pick up a used master cylinder and reservoir instead of rebuilding the stock one. You can find a nice used 11mm to 14mm Nissin or Brembo master cylinder from a more recent bike that will give you better braking with the stock front brake caliper.