Rebuilding master cylinder - manual brakes

[spddm0n]

I just picked of my first C10 and the brakes need to be rebuilt (wheel cylinders all the way around and master cylinder). Since this truck is completely original and unadulterated, I thought I'd just rebuild the wheel cylinders and master cylinder, rather than put in some Chinese-made crap that you can buy in auto parts stores (all the Japanese cars I work on I have to source OEM supplier parts because all the American parts makers are making there crap in China and I just can't stand buying that crap).

I was surprised when I picked up the rebuild kit that there is only the primary piston assembly is provided. It does not include a secondary piston assembly. Why would they not provide all the parts? Would it be best to by a re-manufactured master cylinder instead? I didn't want a "new" one that isn't an original GM part if I didn't have to.

Has anyone else rebuilt one recently? Was the secondary piston assembly in good shape? I'm pretty sure this is the original master cylinder. It appears there really wasn't a lot that needed to be replaced in this truck's short 45K miles on the road (farm).

Also, if you have rebuilt one before, do I need to remove the little brass fitting in the hydraulic line ports? There are new ones in the kit, but I'm not sure I have a flared tube fitting (?) tool to install them.

Thanks for any advice you can offer!

[Steeveedee]

Need pics, but that may be the wrong kit. You may as well replace the flex lines at the front spindles and the one at the rear axle. They're old as dirt, too, and have a tendency to cut loose at the worst times.

[spddm0n]

Hey Steve -
Thanks for the reply. Here are some pics...
This is the pic of the kit I bought...

Also, here are a few pics of what I pulled out of the master cylinder...
Looks like there is some corrosive damage, but perhaps it could be cleaned up properly. I just thought they would include the second piston assembly. ??

Is there a way to purchase one with both piston assemblies? I searched a lot of places and everyone is selling this same kit.

Also, where would I purchase the brake lines for the front and the rear axle? Can those be purchased at a typical parts store or do I need to start getting familiar with specialty websites?

Thanks!!!

[custom10nut]

The MC and the cylinders are "wear out items" and rather inexpensive. IMHO they're not worth the time to rebuild, just buy new ones and you're done.
On the other hand they aren't difficult to rebuld

[Steeveedee]

Originally Posted by spddm0n

Hey Steve -
Thanks for the reply. Here are some pics...
This is the pic of the kit I bought...

Also, here are a few pics of what I pulled out of the master cylinder...
Looks like there is some corrosive damage, but perhaps it could be cleaned up properly. I just thought they would include the second piston assembly. ??

Is there a way to purchase one with both piston assemblies? I searched a lot of places and everyone is selling this same kit.

Also, where would I purchase the brake lines for the front and the rear axle? Can those be purchased at a typical parts store or do I need to start getting familiar with specialty websites?

Thanks!!!

Yeah, that may be the right number on the box, but the parts could have been, as we say in the parts business, "Boxed wrong". It would appear that that kit is incorrect. I bought all new adjusters and spring kits for my truck, and had to take one of the adjusters back because it was the wrong part in the box. You can buy the flex hoses pretty much anywhere. I bought mine at a local NAPA store.

I bought a disc brake conversion kit that nearly all of the components were made in China. It's a sad state of affairs, I can tell you. But if you can't get the right parts, or if the bore of the MC is too corroded, you're probably stuck with Chinesium. Just know that the life of the parts is a lot shorter than real parts. This, I'm certain, is done for a reason- $$$ for repeat purchases.

[spddm0n]

Originally Posted by custom10nut

The MC and the cylinders are "wear out items" and rather inexpensive. IMHO they're not worth the time to rebuild, just buy new ones and you're done.
On the other hand they aren't difficult to rebuld

Interesting that these are considered "wear out" items. Yeah, I looked for new/re-manufactured units, but even Napa couldn't get them anymore. I did look on their ProLink software site, and it showed they have some in other distribution centers around the country, but they always want to change me significant extra cost to bring them in.

[spddm0n]

Originally Posted by Steeveedee

Yeah, that may be the right number on the box, but the parts could have been, as we say in the parts business, "Boxed wrong". It would appear that that kit is incorrect. I bought all new adjusters and spring kits for my truck, and had to take one of the adjusters back because it was the wrong part in the box. You can buy the flex hoses pretty much anywhere. I bought mine at a local NAPA store.

I bought a disc brake conversion kit that nearly all of the components were made in China. It's a sad state of affairs, I can tell you. But if you can't get the right parts, or if the bore of the MC is too corroded, you're probably stuck with Chinesium. Just know that the life of the parts is a lot shorter than real parts. This, I'm certain, is done for a reason- $$$ for repeat purchases.

Yeah, looks like the box has exactly what was in the picture, however, they simply provide the seals for use with the old secondary piston. Interesting choice to do this. Looks like every kit I can find is using the same picture and likely the same contents.

I considered purchasing the whole unit, because I wanted to compare the "new" ones with "re-manufactured ones". I imagine the reman ones are probably a bit better, since they are probably rebuilt original AC Delco units, and the new ones are likely directly from China.

I do have some corrosive damage to my secondary piston, so I'm going to press on Napa to see if they will cover the shipping to get the reman unit in so I can inspect it.

[mike16]

in my experience rebuilt master cylinders are worse than junk. they are dangerous. I pulled a master cylinder apart and all the rubber and springs were new but the pistons were corroded chunks of #$%^.

If you want to keep your master cylinder then buy a new one and exchange the guts.

[spddm0n]

Suck. Yeah, I was afraid that was going to be the only option.
I checked around a little bit and found that I was able to find a couple more manufacturers of the new units, AC Delco included (Rockauto). Strangely, the AC Delco unit photos looked identical to the images for the Raybestos unit. I emailed Rockauto and they told me that AC Delco actually doesn't make anything anymore and that AC Delco was likely selling one, re-branded from Raybestos.

Not sure what I'll do at this point.

[mike16]

they make labels