Rear Brake Bias must go

[IRoss]

Recently I replaced my front pads and rotors, hoping that it would increase my front end performance but it still seems that I cannot lock up my front binders even on gravel... . on wet pavement, for instance only my rear bfg's will be skidding down the pavement with , the fronts give no real impression of doing their job... the RWAL is disconnected electrically but still plumbed in, could this be a source of the problem? What about a master cyl? I read in a brake bias article from a few years ago that stated that the proportioning valves rarely go, but how do I test that? My testing has been conducted with mainly an empy load, and yes, I have bled the crap out of the system. It is starting to feel almost unsafe in the wet weather, any suggestions. .

 

[KOG]

P/U trucks almost always have a fairly heavy rear brake bias so that they'll stop when loaded. That makes them squirrly to the point of suicicidal when empty. That's why RWAL became standard on most of them many years ago. If you want to change bias, the master cylinder has little to do with it. What you need is smaller diameter rear wheel cylinders. I've got RWAL unplugged on mine, but it runs about 3200lbs front 3000lbs rear when unloaded. You don't even want to know how much it runs on the rear loaded.

 

[sdstriper]

You might want to try the RWAL diet. Place that unnecessary weight in the round file...

 

[hotram03]

Is it true that your supposed to bleed an ABS equipped system with the negative battery cable unhooked?

 

[cerberusiam]

The RWAL unit only affects the rear brakes to keep them from locking, not the front. You have problems in the braking system if you cannot lock up the fronts even on gravel. Calipers, lines, MC, and even the proportioning valve will cause issues if it is not allowing full flow to the front brakes.



If you haven't replaced the calipers I would look very closely at them as being the culprit. The factory build and a lot rebuilts have a composite piston that can causing hanging and jamming problems after time on the vehicle.

 

[dpuckett]

Yup, new STEEL piston calipers, new good pads, and rotors if needed. I have only had one turned and it was new. ALso, lines are <$15ea, replace them while you have it all apart.



Daniel

 

[PToombs]

Front hoses will make you crazy too! If the clamps rust they will squeeze the hose, restricting it. Or they collapse on the inside. Either one will restrict flow to the caliper, or back. Then you get slow activation or release.



I hate rust! :{

 

[IRoss]

I have inspected most of the front brake components and all the rubber lines seem in good shape, I replaced the left m/c when I did the rotors and there is no noticable pull to either side when I stomp the pedal so I am inclined to think that the problems lies in the proportioning system... . can I install a gauge on the bleed screw on the caliper to measure the pressure? If so, hat should the readings be? What differences have other members noticed after bypassing the RWAL valve?

 

[Kiohio]

I have the same problem.

It did it before I did the brakes.

Still does it after everything new installed.

Irritatin'... .



KO

 

[cerberusiam]

MC or proportioning valve. Might be worth investing in an adjustable valve to play with the bias to get it right.