Bout time to do the rear brakes. Was thinking I might as well switch to the bigger shoes while I'm at it but wanted some feed back first. Have all the part numbers thanks to the Sticky.

For those of you that have converted, how do they perform? Are they too grabby? No difference? Did you change the cylinders too or just the shoes?

My truck sees all the ranges. Empty, weight in bed, bumper trailer, gooseneck, all the way to 14,000 but mostly in the 2,000-6,000lb range. Wondering about lock up when empty?

Any opinions appreciated before I go to the trouble.

 

i converted to the 3" shoes and the upgraded cylinders last summer and i noticed a nice difference in stopping power. It was not huge but made me feel a little more secure about the braking ability of the truck. As far as them grabbing, i have not at a problem with that at all. Not even on gravel driveways.

 

Mine are grabby when they are wet. Other then that they seem ok. The rear does lock up before the front but I think that is because my rotors are not the best.

 

I replaced all of my moving brake components except the rear brake wheel cylinders 25,000 miles ago; front rotors, calipers, pads, rear drums, rear shoes, brake springs and mounting hardware. Since the drums were new I just increased the shoe width from 2-1/2" to 3" In 25K miles the front pads are wearing at a very slow rate. The rotors are not overheating on long steep grades and in my opinion the brakes seem to be balanced. My anti-lock is disconnected and I have had no problems with unwanted locking up of the rear brakes on a wet road. I was initially concerned that the rears with the smaller cylinders would cause the rear brakes to lock up prematurely. I did a 20 MPH "panic stop" test in front of the house on a dry paved road and all four wheels locked up and slid approximately the same distance. Overall I'm satisfied with the results.

 

Thats what I was thinking of doing. My cylinders are not leaking or anything so I'm thinking I'll just turn the drum and replace with 3" shoes and keep the smaller cylinders.

Thank you for your all's input.

 

we rebuilt the whole back brakes on the 91 with 3" shoes and cut drums, and the upgrade wheel cylinders and it seems like you dont have to push the pedal down as far/hard to get it to stop.

 

Hmmm. Do you think each component upgrade makes an equal amount of difference? What I mean is, does the extra 1/2" of shoe account for 50% improvement and the bigger cylinders account for the other 50% or does one make the majority of the improved braking effect? Or does anyone even know?

 

The bigger wheel cyl would put more pressure on the brakes with less pedal effort. I also thought the wider brakes would make the pin that rides one the wheel cyl piston and pushes the shoes go at an angle with the smaller wheel cylinders. Maybe there is not enough difference to affect angle.

 

I upgraded to both the 3" shoes and 1.125" inch wheel cylinders at the same time. There was a definite improvement – some probably due to the increase in swept area and some due to having brand new parts. My old wheel cylinders were not leaking and appeared to be fine but when I got them off the truck, the amount of rusty gunk inside them was awful.

Rock Auto (http://www.rockauto.com/catalog/raframecatalog.php) is currently having a sale on new Bendix 1.125” wheel cylinders. Part numbers are 33207 and 33206 for the right and left units respectively. At $12.35 apiece I’d go ahead and replace the 16 year-old ones.

 

This is correct but is only part of the equation. You must also factor in the second part that causes this effect. In a contained hydraulic system where you have a master and a slave you also need to factor in your fluid displacement factors. Let me simplify this to a single master cylinder and a simple one ended slave cylinder as an example. If you increase the size of the slave cylinder you must increase the amount of fluid displacement and the travel of the master cylinder to get the same amount of travel out of the slave cylinder. This would give you the hydraulic leverage factor similar to what you have in a hydraulic bottle jack. In a single stroke hydraulic brake system whenever you increase the wheel cylinders diameter you decrease the pedal effort by increasing the travel of the pedal. The only problem I could see with this is the other half of the brake system is hooked up to the front wheels will now be out of balance with the rear half and the front brakes will now be engaging sooner and carrying more of the stopping effort. With all the previous reported cases over the years of high wear rates on our 3/4 Ton front brake pads and rotors both here on DTR & over on TDR I choose to retain the smaller rear wheel cylinders. So this might be the bottom line question - Is adding approximately 30 additional square inches of swept brake drum surface area applied at a slightly quicker rate also decreasing the wear rate of the front rotors & pads? In my case it seems to be working and the brakes seem to be balanced. Also note that I used Carquest parts which were moderately priced.

BTW, the backing plates on the rear brakes are the same between the 3/4 & 1 Ton brakes (same part number according to my local Dodge dealer). The offset is in the shoes.

 

Great info guys. This is the stuff I was looking for. I think I'll just go with the shoes for now plus all the little parts. Will wait and see on the cylinders since they are not leaking yet.
Many thanks,