The Stovebolt Site Forums The Shop Area General Truck Talk Wheel Cylinder Bore

I discovered today that I have a hydraulic leak somewhere in my brake system. Since I can't see brake fluid leaking out anywhere I suspect that one or more of the wheel cylinders is leaking. I went to one of the often used vendors mentioned here to look for rebuild kits and found out that they offer two different sizes, 1" and 1 1/8". The way that they are labelled in the vendor's web site leads me to believe that on a 1/2 ton truck the rear cylinders are 1" bore and the fronts are 1 1/8" bore. I would prefer to have all of the parts available before I tear into the brake system so does anyone know which ones to order for a '63 C-10 LWB Fleet with hydraulic (non power assisted) brakes?

The fronts are 1 1/8". Rebuild kit Napa #36. The rears are 1". Kit #21.

Wrenchbender...thanks for the info.

I don't know what you guys think of this, But I have many times in the past taken my wheel cylinders down to the local machine shop and had them honed up to .010" with a sunnen straight hone. I wouldn't go further than that. Then I used the rebuild kits on them. I have had good luck as long as there were no pits in the bore where the seal rides. They charge me $15-20 for a set.

I haven't had a chance to take them apart and look at them, but I'm hoping that I don't have any pits to speak of, but this sounds like a possibility if I do.

They wll need honeing but you can buy a hone for about $10 at a discount tool store.

Your not going to get the finish and remove metal in any consistent manner with a $10 hone. You need a fixed stone hone like a Sunnen to do a wheel or master cylinder. When I have mine done, I watch them hone it out. I examine after they hone a bit, and then I tell them whether it is good enough or if it needs a little more. I don't go over .010". I just watch where the seal on the end of the puck rides. If it cleans up your far enough. If there are pits where the spring or puck rides near the center, you can leave them. If you are unsure of the final result, replace the wheel or master cylinder or have them resleeved. Any type of flex hone doesn't belong in a wheel or master cylinder in my book.

Many people don't even like to hone an old wheel cylinder. Be careful so you don't make a faulty brake system. It isn't worth the trouble or someone's life.

Thanks for all the input guys...looks like I need to start looking for a shop with a hone.

If it takes over .005 I would consider new ones. Personally I see nothing wrong with the "flex" hones if you have good stones on it. I have used this method for more years than I can recall and never had any problems. I just honed out wheel and master cyl's for a 37 and they cleaned up nice. The best part is I didn't have to buy a "kit" as the springs were still in good shape and a local parts house will sell you just the cups. Just my opinons guys. May not mean much but its free!!!...oh Texmo, be sure to dip the cups etc in brake fluid before assembling.

Brake fluid before re-assembly...got it.

also have had sucess with the three stone flex hones. worked for me.......dave

Hones are for breaking the glaze and "roughing" up the surface only. Unless the cylinder is impossible to get new, I wouldn't bore it at all, I'ld replace or sleeve it.
Scott

Let us know how it turns out Texmo.