Master Cylinder

[white135]

Guys,
Is there any way to identify my new master cylinder before I put it on?
I got it from Sam Winer, and just want to make sure its right. The copy of tech tips I have says that the M211 master looks the same as the M35, and the new one that I got looks awfully new.

Thanks
Eric

 

[M211GMC]

from what I remember , the M211 & M35 Master Cylinders are the same, but no filler tube on the M35 master cylinder.

 

[white135]

Yeah, this one doesnt have a filler neck on it, The guy at Sam Winer said that I would just have to install the neck on it. Will this still Work?

 

[acetomatoco]

Be Careful... the casting is the same.... the valving is different from M35 to M211... do not mix them up or your brakes may not release... caution caution caution.....ACE

 

[acetomatoco]

The extension is not a filler neck, it is additional capacity for fluid as the M135 trucks have 12 wheel cylinders and the M35 only 6....ACE

 

[alphadeltaromeo]

You're a sharp cookie ace

Aint it great to have so many bright minds on SS? I surely think so!

 

[white135]

On the invoice for this master, it has 2530-00-753-9267 on the sheet, this does not match the number in my parts book. Any body confirm this number?

 

[acetomatoco]

2530-741-0830 is for the M135... I have one new in the box original here in my hand... ACE

 

[acetomatoco]

00-753-9627 is the M35 MC... ACE

 

[white135]

Crap is all that comes to mind...

Looks like I have the wrong master.

Not that I'm doubting you, but where is this valving? In my Memphis catalog, the schematic of the master cylinder shows no signs of anything other than a plunger type thingy inside the master.

Always seeking knowledge,
Eric

 

[acetomatoco]

From Bob Kettler's (RIP) Tech Tips.... "Master Cylinder and Air-Pak.. Beware of any surplus Master Cylinder that looks like the one on your GMC. Even if the numbers on it are the same.. They are only Casting Numbers. The 2 1/2 ton Reo 6 x 6 has the same type master cylinder as the GMC but they will not interchange as the valving internally is different, the same goes for Air Paks... Reo ones look similar but are completely different. If you install a REO master cylinder or air pak on your GMC, you're in for one hell of a ride as the brakes will come on and not release or won't come on at all..." (That little plunger type thingy you refer to is a piston and valve assembly in the Reo, btw.) MC rebuild kit for the GMC is DSF5350 and for the M35 is DS FC12208... according to BK. Think about moving fluid for 12 wheel cyls in one stroke versus 6.....would you use the same pump? The valve in the M35 cylinder is LO FC 14263 and in the GMC there is no valve listed....personally, I would not use the Reo Cyl in a GMC... ACE