Brake Upgrade for 2003-2005 vans? Maybe!

[Herbie]

So I got a bug in my ear this afternoon about trying (again) to figure out if there was a path to a parts-bin brake upgrade for my van. It seems like maybe there IS such a path for the 2003+ (6-lug) vans.

As far as I can tell, the 2003+ vans have GMT800-compatible front uprights. The same part#s are crosslisted for brake brackets and calipers between the A/S vans and a number of GMT800 trucks.

Next, I see this thread on upgrading GMT800 trucks to GMT900 front brake setup: https://www.chevyavalanchefanclub.com/c ... es.122524/

From the reading, it looks like the calipers are similar in size, but mount farther out for a 13" rotor, so the upgrade comes vis-a-vis more mechanical advantage, rather than overall swept area. Part #s are given for caliper/bracket combos, rotors, and pads.

The only bummer, from my perspective, is that it looks like the minimum wheel size goes to 17" to clear the rotors. I literally just bought five new Yokohamas a few months ago, so I may backburner this project for a little while, but a craigslist snooping shows me that Colorado or Silverado 17" wheels can be had for cheap with OEM tires in approximately the same ~30-31" diameter most of us lifted guys are using.

I know a lot of owners are happy with their 6-lug brake performance, but my van is HEAVY, and I'm looking for every available option to give me some margin. A front-brake upgrade, a custom rear axle, etc. are all on the wish list.

Thoughts?

[Astrophysics]

Excellent Work Herbie!

My 2003 AWD to 4x4 Astro weighs about 5,600 pounds with all the skid plates, bumpers, rock rails, frame re I for cement and brush guard and winch. My brakes are ok but not spectacular.

If the Colorado 6 lug pattern is the same as 03 to 05 Astro , that is awesome.

I am again re visiting a DIY front sway bar dis connect link using Uni strut p1973 clevis and connecting eye to eye.

Another front end weight saving wild idea, could be the get a spare steel hood from pic n pull. It is heavy. How about cutting out the left side, and the right side and leaving the perimeter to support the hinges and latch. The missing steel would be replaced with aluminum or carbon fiber or fiberglass or even acrylic.

I may still relocate my battery Optima 45 lbs to a place under bench seat.

I bought the Yellow Jacket AC manifold gauge set from Amazon, $118 + r134a adapters. I will check the low side pressure and high side. And see if I can add some r134a . With the dual air on the Astro I figure the shop would try to charge $$


AP

[Bret Schmerker]

@Herbie For my issue 1997 M11006, I'm definitely after more pad area, on as large a rotor as upgrade wheels will permit. The 6-on-5½" bolt pattern for the 2003-EoP General Motors M-Body uses larger rims than my current 5-on-5" pattern and is wide enough for the planned 9" Currie full-float retrofit - I'm after unequal-length axleshafts with 6-on-3" fixed flanges, with the wheel bearing provisions machined into, rather than welded or bolted onto, the tubes; my ideal rear spindles would be front stock replacements for a specific year range of the K/V-1500 Silverado, Tahoe, Suburban, and Avalanche. I suspect that 17" rims would force a GAWR reduction due to the tires being rated for lesser loads for a given pressure than my current 225/75R15 100S's.