proportioning valves.....

[Siqx20]

Ate they really nessesary on our trucks? I

I stripping my truck down to bare frame atm and that mess of shit I would really like to just do away with if I can. Im running stock everything brake wise

[datzenmike]

The 620 doesn't have a proportioning valve. What or where are you looking?

[420n620]

maybe he mean the load sensing valve aka NLSV. just a guess. :blink:

[Siqx20]

Its in the middle of the frame. All my break likes go to it and then go to the wheels from there.

[datzenmike]

maybe he mean the load sensing valve aka NLSV. just a guess. :blink:

 

(I'm sure he does)

 

Its in the middle of the frame. All my break likes go to it and then go to the wheels from there.

 

 

Under the pass seat? Yeah that's the NLSV.not a proportioning valve. And besides you would never remove a proportioning valve even if it had one. A proportioning valve allows less braking to the back wheels to prevent lock up as the weight shifts forward under heavy braking. Removing it would cause the rears to lock even under moderate braking effort resulting in a loose rear end that will skate around you in massive oversteer.

 

The Load Sensing Valve works almost the opposite. It allows more braking effort to be applied to the rears in direct response to how much weight is riding in the back. More weight = more traction = can handle more braking power.

 

This is the braking system. The single most important safety system in any vehicle made. Removing brake components because they are "a mess of shit" seems hasty to me. No one can see it under there anyway..

[420n620]

Its in the middle of the frame. All my break likes go to it and then go to the wheels from there.

yep, that's where it's located. :thumbup:

 

(I'm sure he does)

yep, he does.

[Siqx20]

Hmm so I Prolly need that then lol

[datzenmike]

Truthfully it is active only when the back of the truck lowers from weight added. The valve itself is tilted upwards slightly with a heavy steel ball inside. Normally on hard braking the ball is forced forward and closes a valve to limit brake pressure to the rear wheels. As weight is added the frame (and the valve on it) is tilted down at the rear increasing the slope the steel ball must climb allowing more pressure to the back wheels. I would just leave it alone.

 

This is a very simplified description

[jesusno2]

that load sensing valve thing also fucks ya if you swap to rear disc it restricts flow to much to operate the rear brakes correctly best to by pass it and add a real proportioning valve to get the balance back. gone through this with a few king cabs. the early 620s dont use that valve.

[Siqx20]

Well im bagging my truck if im running not a even ride height will it mess with my brakes? I think im gonna remove it...I wont be hauling anything heavy in the back of my truck anyways.

[ggzilla]

No, lowering the truck won't upset the brake balance. Which by the way is built-in by the Datsun engineers. That's why they don't need to use a proportioning valve. The engineers selected appropriate front & rear cylinder sizes to obtain the correct proportion.