need some quick brake help
 

I Have a 77 heavy half and I am about to buy new rear wheel cylinders. They come in two sizes according to autozone website. I have the HD 1.25" brakes on the front so would that mean I would have the larger size wheel cylinder? I know the diffrence is in the size of the brake shoe or the drum. My drums have a Max Diameter stamped into them but not sure is that is the actual size i need. Any help is appreciated.

Re: need some quick brake help
 

Measure the width of the rear pads. the big pads take the big cylinder. Base are 2", HD are 2 3/4".

Re: need some quick brake help
 

Here's a link to the brake system release charts for '74 (and '87).

Find your model/option type on the chart and it will show you what wheel cylinder is required.

http://67-72chevytrucks.com/vboard/s...d.php?t=510519

These are the actual charts that we referred to in order to release parts for production.

K

Re: need some quick brake help
 

The "Max Diameter" is a reference to the largest diameter the drums can be safely turned before they must be scrapped. Doesn't have anything to do with the friction material, wheel cylinder or brake system info.

So - in looking at the '87 chart for a 10 series pickup ('cause it's a little easier to read) the 2" wide shoes take a 1.062 dia wheel cylinder (aka an inch and 1/16th) and the 2.75" wide shoes take a .9375" (aka 15/16ths of an inch) diameter wheel cylinder.

K

Re: need some quick brake help
 

I just did this, when you take the cylinder out it will tell you what size it is, then just go to AUTO ZONE or where ever and pick it up.