[Sandro]

05 silvy 2wd Crew cab... is it possible to adjust the brake proportioning valve? I'm on my 3rd set of rotors in 2 years (70k) I think that I'm getting too much line presure at the fronts and rears aren't taking their share of the braking load..

That is perfectly normal. Under braking, a large portion of the vehicle weight is transfered to the front (inertia force). As a result, over time the front pads/rotors do wear much faster than the rear. Front/rear brake bias is induced in order to prevent the rear wheels from locking (easier to lock than the front because unloaded). Putting more pressure on the rear brakes will likely not improve your overall braking power. Most of the labor still has be performed by the front.

 

[Sandro]

yes I am aware of the physics involved...Same reason you have dual discs on the front of a mortorcycle.. and why the discs are normally larger up front than on the rear of 4 wheel disc vehicles..
But it seems that the brake setup on my truck is set too strongly for the front. Brake rotors should last longer than 6 months.. after 3 sets, something is not right.(probably the fact that GM put itty bitty rotors on the front of a net 5000lb vehicle) It's like my rear brakes do not even engage...so I want to test the proportioning setup to see.. I'm not trying to improve my overall braking performance.. I'm just trying to get my rotors to last longer.

Sure, I understand and agree with your concern. I believe I read in some other posts that it may due to the material of the OEM rotors. A relatively soft steel that gets eaten up quickly.

Another aspect you may want to consider in your test is that if you have 4 wheel ABS, the ABS may overlap with the brake bias induced by the proportional valve (please note I am just thinking aloud - not talking by experience). This should somehow ease the concern of locking up the rear by modifying the bias.

Please keep us posted.

 

[Sandro]

I was also thinking that the ABS might help prevent rear lockup... but my problem now is this Proportioning valve..

Jimminey this thing is huge.. it looks like a giant booster.. has a big electric motor and looks like electronic controls ...

Anyone Know how to adjust this thing? or do I need to get my tuner buddy to do it through the PCM?

I googled for your vehicle and found it came with an "Electronic brake distribution" Don't know what does this mean but from your description it looks it could be indeed like some sort of computer controlled system http://www.internetautoguide.com/ca...00-hd-short-bed-crew-cab-pickup/24/index.html listed in the Handling section

Hopefully, someone with more knowledge than us will chip in in this discussion...