Combination valve/ eliminate the block????

[76zimmer]

I plan on removing the combination valve/ brake warning switch block to simply make a standard one line Front, one line Rear system. I will put a proportioning valve in the rear line for adjustment of the system as needed for my particular combination.
I will have 4 wheel discs, and plan on using the stock vac booster, and pedal assy. with a 1 ton m/c. I know there is a thread about that here in the garage. I will have 3/16" lines throughout.
I have about 6" lift going on.

So my questions are:
1) Will I lose anything other than mentioned above by removing the combo valve?

2) I have a model year 85 D60, with the stock calipers on it right now, and I will replace them. Any problem putting a 79 caliper on there, to get the SAE sized brakelines instead of metric?

3) Anyone have a set of braided line part #'s for the 6" lift and 79 calipers?

 

[4X4HIGH]

I would keep the stock proportioning valve if it were me. There is nothing wrong with them and i'm currently using mine with a 4 wheel disc set-up with no issues.

 

[76zimmer]

thanks for the input Scott. I've read the block isn't very useful after switching to discs' and different suspension etc. That the stock block is calibrated to the original vehicles parameters....or something like that. Mine is rusty, and the old lines frozen in it. I thought I would just skip it and control brake proportioning with a manual valve to the rear.
Does the stock combo valve have residual valves in it for the drum brake rear system?
I've read that should be removed for a disc setup also.

 

[4X4HIGH]

There is no residual valve in our systems. A residual valve is used if the master cylinder is mounted lower than the wheel cylinder to keep fluid at the wheel cylinders rather than flowing back to the master cylinder and making the wheel cylinders retract back too far. Same for if it were calipers.

 

[sweetk30]

i have run tee fitting for front and adj reg for rear . few test drives works just fine for me.

1 ton brakes with disk rear.

 

[76zimmer]

There is no residual valve in our systems. A residual valve is used if the master cylinder is mounted lower than the wheel cylinder to keep fluid at the wheel cylinders rather than flowing back to the master cylinder and making the wheel cylinders retract back too far. Same for if it were calipers.

thanks Scott, I was under the impression that block had all that stuff in it, therefore application specific. I've also read (can't always believe what you read on the internet though) that m/c from the factory would have a residual valve in the rear brake port, under the tapered seat?

 

[76zimmer]

i have run tee fitting for front and adj reg for rear . few test drives works just fine for me.

1 ton brakes with disk rear.

thats what I was leaning towards Brett. Pretty simple, and get rid of my POS combo valve. Easier to run new lines this way too.

 

[MNorby]

I am just running a manual proportioning valve on my rears. I just kept stabbing the brakes and adjusting till front/rear bias was good.

 

[dhcomp]

When you eliminate the proportioning valve, what happens if you blow either a front or rear line? Isn't that valve what basically shuts one half of the system off and allows the other half to save your life?

That has always been my impression of why the prop. valve can "lock" front/rear when bleeding, and is supposed to be bled with those little nipples on each end held in place.

 

[MNorby]

I'm not sure on that but I have a line lock solenoid coming off each port of the master cylinder and a ball valve before the brake line goes into my rear cutting brake m/c so if a system were to have a problem I could effectively turn it off.

 

[76zimmer]

When you eliminate the proportioning valve, what happens if you blow either a front or rear line? Isn't that valve what basically shuts one half of the system off and allows the other half to save your life?

That has always been my impression of why the prop. valve can "lock" front/rear when bleeding, and is supposed to be bled with those little nipples on each end held in place.

The dual reservoir m/c provides that purpose.
And it certainly dont stop like all 4 wheels working, but at least it don't free wheel coast.