Front Brake master cylinder cleaning

[davestrike]

Hi All,

My question is this:

How can I clean out the front master cylinder for the brakes without having to remove all the inner parts?

When I opened the reserve, I found water, oil, and this white sludge. When I tested the pump action, it appears to pump fine, but that white sludge is still in there.

And if I do need to remove the master cylinder, just how the heck do I do it? I cannot even see a clip ring.

Thanks for all your help in advance.

[pggg]

Dave, if you're not into stripping and dismantling things, then simply pump and bleed, pump and bleed - get heaps and heaps of new fluid thru the system till it's lookin' good again.

PS there IS a circlip - it'll be hidden with rust/gunk

[TopCatGr58]

Dave,

You might want to just get a bunch of shop towels, or a NEW suction bulb, something that you can use to remove a lot of the old fluid and CRUD in the MC, then pour in some new fluid, stir if you want, then remove it, etc., until it looks relatively clear, and then pump and bleed it thru the system like PGGG said till it's clear at the caliper!
T.C.

[mro]

Some things just suck

I use my shop vac on MC's that are working.
Stuck a length of fuel line in vac hose and held/covered the large vac hose opening. It sucks out most of the crud on the first try, fill and repeat several times. Then fill and pump till clean brake fluid is coming out. (should be almost immediately)

Do simular job on brake lines. Suck out the old fluid then dip one end into brake fluid and suck some thru hose to clean it.
Seems to work very well.


mro

[davestrike]

Thanks All!
I will give it a try on the suction and new until clean.
Sounds much easier than I first had thought.

[mro]

I will give it a try on the suction

Try not to vac up any loose parts.
Really sucks having to muck around in the bottom of my shop vac to find a screw or nut. (I use it to drain hydraulic systems and radiators too and remove engine oil now and then, 30 gallon tank )


mro
btw, first time into the brake system?
May want to use the search function and read about bleeding em......

[fredintoon]

You need a long tool

Hi Dave,
the master cylinder innards are held in by a single circlip. But it's way down in the bore and the normal circlip pliers won't reach down far enough to get it. MikesXS (and doubtless others) will sell you a long enough pair.
Fred Hill, S'toon.

[pggg]

Another thing with master cylinders, their reservoirs have a tiny, cunningly designed one way breather notch in the lid, and with the XS lid you don't want to over tighten those 4 philips screws, the rubber diaphragm inside only needs a light seal, too tight and the breather notch could get restricted

[cajun31]

IMHO

If you are seeing that much gunk in the master I would suggest that you take everything apart and clean it. Brakes are not something you want to take a chance with. Rebuild kits are very inexpensive for the piece of mind it will give you knowing they are right. Check out the tech tips on this site and do the job right.