Need a front master cylinder.

[Cobia]

Hey Folks,
Both MCs on the 79F I just got are really trashed. The rear one was full of rusty water and the front one was almost frozen solid.
I'm getting a replacement for the rear one from Andreas but he didn't have a front one.
Anyone have a front MC laying around that you can bring yourself to part with? I would really appreciate it.
Gracias, Amigos

[FJ111200]

If you ain't too bothered about keeping it standard, use one from an FJ, i have.

[Cobia]

Thanks

Check your messages FJ.

[DiverRay]

I may have one here, if you don't have anything yet. It's not perfect, but if you can use it, let me know. I replaced the one on my old daily ride with a brand new, NOT clear plastic one.

[jeffe]

I replaced my front MC from a newer model Yamaha. It wasw either a Fazer or a radian. That was over 3 years ago and no problems. It was under $40 used form a used part place

[fredintoon]

Hi Cobia,
if you can't find a used replacement try MikesXS, he carries several M/Cs for the XS650 with their bore diameters clearly stated. They ain't even prohibitably expensive.

[Rasputin]

I am going to pick up a parts bike tomorrow (hopefully) and maybe I will have one for you. I will let you know if it is useable.

[Cobia]

Thanks everyone!!

[Cobia]

Well, I dug in!!

With the not so good prospect of buying a bolt-on-and-go I decided to dig in and see what I could do. I bought a re-build kit from Goeorgefix (ebay in FL) and decided to tear them down and make an assesment.
After much cajoling with rust and frozen parts this is what I found after the tear down:





As I had said, the rear MC was full of water and pretty much rusted up as you can see from the reservoir in the pics.
The front one, not much better. But after tearing them down and cleaning them with "Gunk" (least offensive to most materials) they turned out fairly well. A couple of days ago I went to Harbor Freight and bought a set of "mechanic picks", boy did they come in handy in removing the circlips and the deposits left from the "caked on" residue.
The only part I find that will need replacing is the metal flange that fits between the reservoir cover and the reservoir diaphragm (sp?) for the rear MC. Other than that, I think I'm OK. after I order and get a MC re-build kit for the rear MC.
This is what the pistons inside the MCs looked like:



Notice the rusty piston fron the rear MC!!
BTW - It was cold day in FL today - 68 degrees during the day and this is my view from the work table in my back terrace:



Another day in paradise!!

[bikerphil]

crud

Wow. Those parts look like they were sitting on the bottom of a lake.

[Cobia]

That's why I was looking for replacements

Yeah man, I had a little time on my hands and decided to take on the challenge of discovery...!!! That's what I found, and that's after intensive wire brushing and scrubbing with "GunK" in a parts scrub container. Actually, both cylinders look pretty good inside, with no gouges to wonder about whether they will work with a new re-build kit. The only nasty parts are the "metal flanges" that go between the reservoir cover and the diaphragm (sp?), all rusted out. And the fact that the diaphragms look like worn out and hyperextended condoms!!

[egsols]

Hey Cobia,

My flanges looked bad too but with a bit of wire wheel work they turned out 100% better.

[Cobia]

Flanges

Egsols,
That's what I plan to do, but the rear one has lost a lot of metal to corrosion. I want to make sure I don't leave sharp edges that will cut the diaphragm (finally got the spelling right, after looking it up in Webster's..lol).
Bottom line our friend Andreass has come to my rescue with a ready to go rear MC. And I'm getting a couple of front ones from Garrett that will be good for parts and/or rebuilding.
The carbs will need cleaning but I figure I have to make sure it stops before I get it roaring down the street. I know myself.....

[CatatonicBug]

I have to make sure it stops before I get it roaring down the street.

Nice forethought! Gotta be able to stop before trying to go.

[Texas Rookie]

Cobia,

Thanks for the update on this aspect of XS resuscitation. Pics were very helpful in figuring out that these parts had been soaking in the bayou teche rather than the rio grande river (it's important to know where the gunk comes from so you know what kind of solvent to apply, bayou teche gunk yields to equal parts jax beer, white lightning and tobasco sause where as rio grande river gunk responds better to equal parts budweiser, the cheapest mescal you can find (aka low grade gasoline) and mama ninfa's picante salsa (the green one that will take out your tongue and all your tastebuds in one quick driveby))

Like your priorities too. Always whoa before goa (didn't used to be that way at all, glad I growd ep).

where is the best place to get piston seals for calipers (seems like that is about the only part to rebuild on these).