Complete "Spongy Brake Feel" Write-up

[sparg93]

Ok, so i've been doing quite a bit of reading on our crappy stock brakes sporadically for the last few months. The reviews were great and tons of good info, but no technical data to go off (i.e. braking distances).

So, i was thinking of doing a complete review of the components individually (and in combination) so folks could make an informed decision of budget v performance. Anyone interested??

Here are the upgrades planned:
Hawk LTS Pads
Power Slot Rotors
Goodridge SS Lines
3/4 ton calipers
Synthetic Brake Fluid


My ideas for testing (the order of how I would perform them)
1) Test just the improvement from new brake fluid - all the original hardware stays on, just a brake bleed
2) Test Stainless Steel lines - keep original equip on
3) Test the new brake pads - keep the original calipers and original discs on
4) Test the new discs - original pads and original calipers
5) Test new discs and new pads - retain original calipers
6) Test new caliper - use the new discs and new pads (no need to test new caliper on old pads, it will definitely worsen braking)

My one concern - I've heard of seeding new pads to new discs...if I run the tests above, will I essentially screw all of that up by mixing the new pads with old and new discs?

If it turns out I should only use the new pads on the new discs, I'll do the following instead:
1) Test just the improvement from new brake fluid - all the original hardware stays on, just a brake bleed
2) Test Stainless Steel lines - keep original equip on
3) Test the new brake pads and discs - keep original calipers on
4) Test the new caliper - use new discs and new pads (3/4 ton caliper won't be tested with old pads)

If you have a recommendation for a different test or changing up the order on either scenario, please let me know!!

My thoughts are to run the truck up to 60mph x3 and measure the distance. In between each test above, the brakes will certainly have time to cool down as I change out the components. For each test I'll also allow the new components to warm up over a 15 min period of driving in the same area.

It's going to be impossible to control all the variables (ambient temp, hardware temp, etc) but i'll try to keep it as controlled as possible. I'll also take photos of the work in progress so everyone can see.

Anyone interested in this info?

 

[bowtiefreak]

In for the outcome. This will be a VERY usual tool when done.

I run the hawk pads, SS line, slotted rotors. It was a big help.

Please also not the wheels and tires that you are running with sizes.

 

[blueflamed03]

that'd be some great info!

 

[sparg93]

Certainly - I put together the specs on my truck when I write the overview.

Also, I'm doing this in Central NJ (Freehold) next weekend if anyone wants to join. If you want to bring your rig, I'll show you how to do this swap and we can work on your truck as well.

 

[moviewithnotitle]

sparg93,
Did you ever complete this setup and testing?

 

[sparg93]

Almost!

I have the 3/4t calipers and 3/4tpads on but I haven't had a chance to "test" them due to all the snow.

One adjustment is that it was recommended that i don't swap the 1/2t pads onto my new rotors b/c i was pairing the new rotors up with a different pad material and size (i.e. 3/4t HP pads)

So, the big measurements will be:
1) Stock
2) 3/4t calipers & 3/4 pads
3) 3/4t calipers & 3/4 pads & stainless steel lines

Subjective statement:
The pedal has firmed up a little bit at the top. The big difference I've felt is after the first few inches of pedal travel the truck stops faster...you can feel the calipers/pads grabbing harder then stock.

It might just be me, but I've noticed a BIG difference in stopping in the wet. I was driving last night is freezing cold rain and the initial bite the pads had on the rotors was something I have never felt before...amazing. Usually it takes a fraction of a second for friction to set in, but this setup grabbed instantly. My guess is the slotted option on the rotors helped b/c that is their expected benefit.

I wish i could have isolated the benefits of pads and rotors individually...but i would have to buy another set of $75 HP pads and run them on my original rotors. If anyone wants to contribute to the fund, I'd be happy to take donations and then send the lightly used pads to whoever wants them.

My next project is measuring the mpg difference the Big 3 upgrade makes and then a complete tune-up...i had to do the Big 3 b/c of subs i added and some people stated they noticed a mpg improvement when they did it.

Stayed tuned - i will def post when the measurements are in!

 

[Jaycenk]

I have a feeling one step may be added.
Removing the abs modual. I have been told by 2 GM master techs that this is the source of weak braking in our trucks. Odd thing is it changes from stop to stop.

 

[sparg93]

Interesting about the ABS module - did they elaborate on why it would be better to remove?

On a mechanical note, I believe adding a brake booster from the 3/4 or 1t series would help firm the pedal immensely. There's a writeup for how a guy did it, but i'm not sure if it justifies the expense...but I really want that brake booster/master cylinder upgrade b/c it makes complete sense for helping our rigs stops.

 

[dsltrc]

Did u have to modify the 3/4 pads to fit the rotors.. I'm looking at doing this upgrade too but from what I've read the 3/4 don't fit without grinding away extra metal...

 

[sparg93]

Yes - you have to grind the backing plate on the pad....but it's really easy (you will need some form of tool to do this - i used a stationary grinding wheel)

There is a plate on the back of the brake pad that is used for mounting the pad within the caliper. This mounting plate will rub the tophat on the rotor if you install "as-is" on our 1/2t setups.

Simply grind the inside of the mounting plate so it's flush with the pad material...essentially your grinding away the part of the back plate that sticks out below the pad material.

It takes <5min and as soon as you get the pads you will know what I mean if my description makes it hard to visualize.

The best part is the 3/4t calipers mount directly! I highly recommend AC Delco's remanufactured. I was VERY happy with my set and they honestly looked brand new and came with all the hardware and lube.