Re: highway speed in full time 4X4?
 

Jeeps got the combination valve in 74 according to one of my manuals to
prevent rear wheel lockup under hard braking.

Mike

"L0nD0t.$t0we11" wrote:
>
> Roughly 1/7/04 13:48, CRWLR's monkeys randomly typed:
>
> >
> > I always thought the job of the portioning valve was to balance the braking
> > "power" equally, or proportionally, between the front and rear brakes.
> > Without the portioning valve, the rear brakes, especially on a front disc
> > brake system would not have the proper braking pressure appled even if the
> > brakes were properly adjusted.
> >
>
> Or on a combination disc/drum brake system or pure drum/drum or
> anywhere that weight transfer unloads the rears so they tend to
> lock up if fed the same hydraulic pressure as the fronts.
>
> Actually I've been wondering why this topic is relevant for Jeeps?
> Is the addition of a brake proportioning valve some sort of
> recent ["recent" in terms of someone other than Bill H.]
> mod or something?
>
> I can remember drum/drum brake systems that had a proportioning
> valve to send more to the front brakes to avoid rear lockup
> due to weight transfer waaayyyyy back on sports cars and
> in the 60's on 'merkin ones.