Which Master Cylinder Repair Kit?

[69Z28-RS]

I just ordered an Master Cylinder Repair Kit for my '69 Z28, and was sent an MK472 (which has a 1" dis piston).   
My Z28 has a 1-1/8" piston, so I'm returning the MK472 (unless one of you fellas need it for a different car combo?).   Is the MK1108 kit correct for the '69 Z28 MC?   It's very difficult to get specs on these parts from the online sellers...

Gary

[bertfam]

According to the RAYBESTOS CATALOG, the kit you want is their P/N MK501.

Ed

[69Z28-RS]

Thanks Ed,

I'll check that one out...

[bertfam]

Looks like NAPA sells it under their part number UP 501.

Ed

[69Z28-RS]

I'd checked with the local NAPA stores; no one had one for my car.. at least in stock.
I'm checking for the Raybestos MK501 - I confirmed you are correct re the application.   that one should have the 1-1/8" piston...
Thanks again:

PS.  I have the MK472, that will cost me $$ to send back to Rock Auto.   If someone has a 'Camaro with 1" piston MC (ie. drum brake cars), I will sell it to them cheap; I was told it was the last one they had when I ordered... 

Gary

[bertfam]

Gary, I'm assuming you have your original master cylinder, and if so, do what I did. Go to your local auto parts store and get a REBUILT MASTER CYLINDER. They're only $17 or so, which is about 10 bucks cheaper than the rebuild kit!!

Transfer all the internals from the rebuilt one into yours (and put your old parts back in the rebuilt one), and then return it as the core and you'll be up and running again! All the internal parts are the same between the original and the rebuilt, so it's an easy swap. Not only that, but NONE of the rebuild kits come with the secondary piston which is usually chewed up more than the primary!

Ed

[Steve68]

Have you tried Advance Auto or Auto Zone?  They have retail as well as on line stores.

Steve

[Stingr69]

Gary, I'm assuming you have your original master cylinder, and if so, do what I did. Go to your local auto parts store and get a REBUILT MASTER CYLINDER. They're only $17 or so, which is about 10 bucks cheaper than the rebuild kit!!

Transfer all the internals from the rebuilt one into yours (and put your old parts back in the rebuilt one), and then return it as the core and you'll be up and running again! All the internal parts are the same between the original and the rebuilt, so it's an easy swap. Not only that, but NONE of the rebuild kits come with the secondary piston which is usually chewed up more than the primary!

Ed

Same here. I just posted in the other MC rebuild thread. This IS the way to go.

-Mark.

[69Z28-RS]

I appreciate those comments and recommendsations.

If I have to, I wil do that, but I plan to use DOT 5 fluid, and typically rebuilt/new cylinders use DOT 3 as an assembly lube.  it's also recommended not to use DOT 5 fluid, when the rubber seals have been wet wtih DOT 3 (although I'm ignorant of any chemical reasons for this).   I'll continue looking for a rebuild kit, and if I can't find one.. I may have to use that route... and then I'll be faced with using DOT 3 vs DOT 5.

Gary

[Stingr69]

Gary,
The DOT 5 thing is a constant internet battle. The theoretical problem with using DOT 5 after DOT 3 is the rubber stuff supposedly absorbs the DOT 3 and any moisture it absorbed during service. The theory is it will leach out an cause corrosion after the DOT 5 is added. New rubber parts should not need to worry about that. I used DOT 5 during the system rebuild and never looked back. I would do it again in a heartbeat. Zero maintenance in 10 years and it still stops like a new car.

-Mark.

[69Z28-RS]

i've rebuilt 3 cars brake systems over the past 25 yrs, using DOT 5, but in each of those cases, I rebuilt/replaced every rubber part, and flushed all the lines with alcohol and dried first.   In each of those cases, I've had no reason to do any further work on the brakes, and those cars *sit* 99% of time..  and the brakes are always good when I drive them!   I'm a believer, but I also do it *right*.. and use fresh rubber parts, and use DOT 5 as the assembly lube when assemblying the parts..

Gary / 69Z28-RS

[sdkar]

I agree completely with Ed Bertrand on this.  I have done this as well and found they are cheaper than the rebuild kits.  When I returned the core, the parts guy became confused when he opened the box to inspect the returned master cylinder.  He thought I was trying to return an unused part, which I guess I could have gotten away with, but I was honest.  You can also do this with alternators as well.  I wonder if this would also apply to the water pump, but will have to find out when mine goes out.

Also, don't forget to hone out your bore before swapping the parts out or you may have your rebuilt master cylinder fail quickly.  I'm not sure about now, but it was not too long ago that you could ask the guy to go through the rebuild master cylinders (and alternators) he had in the back and you may get a correct looking one.  I was lucky on a few occassions and was able to get a rebuilt one with an gold anodized cap instead of a black one and external bleeders.  In fact, he had three different looking master cylinders all under the same part number.  I also was able to get a correct alternator with a gold pulley instead of a painted black one along with a correct build date by having the go go through the boxes for me.  After buying the part from him, I gave him $5 for his help.  Well worth it to me.

[69Z28-RS]

thanks for all the comments (which I do agree with)..   After disassemblying my MC, I found where it sat so long (32 yrs), it accumulated a little water and there is a rough area on the bottom of the cylinder that doesn't look like it will hone away.. so I'm probably going to send it to WhitePost Restorations for brass sleeving and rebuilding ($175 and LT warranty).  I've used White Post before, but it was on an early Corvette MC, and now Billy has passed away.   

Does anyone recommend any other shop for sleeving?  My MC is the original one and worth the cost.   

Did you guys know there is a casting date on the side of the Delco Remy MC?   Mine is dated '175' which should correspond to late June and my car is a 09C (Sept) with a late August engine.   The MC also has a 'D4' cast into it, just below the '175 date code'..  anyone know what the D4 is for?

Gary

[Kelley W King]

White Post is the place. They rebuilt one of mine after 15 years. ( i still had the receipt )

[JohnZ]

  The MC also has a 'D4' cast into it, just below the '175 date code'..  anyone know what the D4 is for?

Gary

The "D" is for the Danville Foundry, which supplied most of Delco-Moraine's raw castings, and the "4" is the foundry pattern number the sand mold was made from, for internal traceability.