Transmission/pinion angle issue... '68 Charger shakes hard on the freeway. Help!

[bobs66440]

I agree with Mike and elacruze. Especially since you are feeling it mostly in the steering wheel.  

It doesn't apply here, but as a side note, the only time you would need a residual valve to the front in this situation is if it's on a hot rod or similar where the master cylinder is located under the floor board (lower than the calipers/wheel cylinders). They would then be used to keep the fluid from gravity bleeding back to the master cylinder.

[ncmiller1]

Well, looks like it was the residual pressure valve.  Thanks musicman and elacruze! Once i pulled it out, almost all the shaking disappeared.  I say almost because there is still a little shaking when I brake, so now I have to see if I warped the rotors due to overheating them.  Still very happy though!

[bobs66440]

there is still a little shaking when I brake, so now I have to see if I warped the rotors due to overheating them. 

Yep, that's what it sounds like. Good call guys. 

[charger Downunder]

Great to see it fixed but who put this in.
This is due to the fact that there is a 2 psi check valve installed in the brake line going to the front calipers from the master cylinder.

[Chryco Psycho]

Using a drum brake master on a disc brake system can cause the problem , thee is a residual pressure valve behind the brass flare insert in the master but iit has to be removed for disc brakes

[charger Downunder]

Using a drum brake master on a disc brake system can cause the problem , thee is a residual pressure valve behind the brass flare insert in the master but iit has to be removed for disc brakes

Thanks always learning new things.

[Chryco Psycho]

you can remove the brass insert with a drywall screw & pull outthe rubber residual pressure valve & re-install the brass insert