Any legitimacy to this equation?
I realize the proper way, but in advance of redoing the entire braking system, would like a basis to start.
LSPV Adjustment with Pictures
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Any legitimacy to this equation?
I realize the proper way, but in advance of redoing the entire braking system, would like a basis to start.
I'm trying to adjust mine today back to stock ride height, and I'm wondering if the rod going back to the back axle is supposed to be straight or have a bend in it?
Chris
Chris
Designed with a curve in it.
I lowered mine at the rear diff all the way and I finally have rear brakes again. 
Chris
Chris
I lowered mine at the rear diff all the way and I finally have rear brakes again.
Chris
That seems odd to me. The valve is designed to provide more rear brakes when the rear of the vehicle is heavily loaded. When loaded the body would sit lower and that would push the arm up for more rear brake bias. When unloaded the body sits higher, pulling the lever down for less rear brake bias.
If lowering the rod gave you more rear brakes, you've got something else going on back there
I thought so too but I think my rod was bent from having the lift bracket on the truck when I had the 6" Slee Lift.
Folks, the only way to adjust this and know for certain what it is doing is by the FSM with a brake pressure gauge.
See this post for a correct way to adjust the LSPV, including what parts you need and where to get them. T
http://www.risingsun4x4club.org/forum2/showthread.php?t=17274&highlight=lspv
It also works if using a Wilwood adjustable valve as a replacement.
See this post for a correct way to adjust the LSPV, including what parts you need and where to get them. T
http://www.risingsun4x4club.org/forum2/showthread.php?t=17274&highlight=lspv
It also works if using a Wilwood adjustable valve as a replacement.
Very true.....some people would be very surprised at the lack of pressure and bad distribution they have.
When I first put on the pressure gauge (after doing all the measuring and full skid on dirt stops) I thought I had it about right. When I installed the gage (goes where the brake bleeder screws in) I only had 300 psi to the rear brakes.
Now I KNOW what the brakes are doing and the wear pattern is back to normal.
The kit is so cheap and easy to use, I cannot understand why anyone would not want to get this right.
Kudos for this info. I adjusted mine and wow what a difference! This is a must do after a lift is installed.
I've got a 4" (100 mm) HD lift with Dobinsons springs in my 80, and I have a 3" (75 mm) adjustment bracket from Superior Eng on the axle housing. The rod to the LSPV is hard up against the underside of the upper left trailing arm, as others have mentioned too. I have the 4" (100 mm) version of that bracket here, but obviously if the rod is interfered by the trailing arm with the 3" bracket, the 4" one is going to be worse.
I'm going to try lowering my LSPV down by 5 or so mm and see if I can get the rod to connect back to the axle housing without needing any non-factory bending or the Superior Eng bracket. For those who moved their LSPV (without having a bracket on the axle housing), how much difference does it make to the proportioning of hydraulic braking force going to the front calipers? If you were to lower the LSPV and still use a bracket on the axle housing, but a smaller one (say for a 2" or 50 mm lift) what sort of effect is that likely to have?
Obviously without doing it the fully-correct way using gauges, etc. or checking that the LSPV itself is properly bled, things may not work as expected anyway. I've considered fitting a new LSPV because the current one and it's bracket are so awfully rusted, but trying to avoid doing that right now.
Craig.
I'm going to try lowering my LSPV down by 5 or so mm and see if I can get the rod to connect back to the axle housing without needing any non-factory bending or the Superior Eng bracket. For those who moved their LSPV (without having a bracket on the axle housing), how much difference does it make to the proportioning of hydraulic braking force going to the front calipers? If you were to lower the LSPV and still use a bracket on the axle housing, but a smaller one (say for a 2" or 50 mm lift) what sort of effect is that likely to have?
Obviously without doing it the fully-correct way using gauges, etc. or checking that the LSPV itself is properly bled, things may not work as expected anyway. I've considered fitting a new LSPV because the current one and it's bracket are so awfully rusted, but trying to avoid doing that right now.
Craig.
After an 850/860 (Heavy/Medium - F/R) OME 2 1/2" lift, I tried moving mine the typical 5/16" I read on 'mud somewhere. My brakes still sucked.
I ended up taking the cross bolt out at the eye and feeling how the arm felt as I moved it. I found a point of decent change in resistance and adjusted the valve position and the up/down of the arm at the linkage until it was right at the transition point for the valve when sitting level unloaded. I thought I could feel how it might have operated. It's like if the back end lofts up, the rear brakes get more pressure because of this valve. Or, does it unload the front brakes somehow??
All I know is my brakes seemed a bit better because of it. This may have all coincided with brakes getting broke in. I had replaced just the pads while I sorted out the rest of the stuff. When I did my brake rotors, calipers and new pads early this year, I bedded them in properly and it made a huge difference. I'd heard others say they could almost stand their truck on the nose, now I believe it!
I ended up taking the cross bolt out at the eye and feeling how the arm felt as I moved it. I found a point of decent change in resistance and adjusted the valve position and the up/down of the arm at the linkage until it was right at the transition point for the valve when sitting level unloaded. I thought I could feel how it might have operated. It's like if the back end lofts up, the rear brakes get more pressure because of this valve. Or, does it unload the front brakes somehow??
All I know is my brakes seemed a bit better because of it. This may have all coincided with brakes getting broke in. I had replaced just the pads while I sorted out the rest of the stuff. When I did my brake rotors, calipers and new pads early this year, I bedded them in properly and it made a huge difference. I'd heard others say they could almost stand their truck on the nose, now I believe it!
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With OME 2 1/2"....just did this adjustment on my Rust free cali LX, nuts broke free, dropped 1/4 inch....feels better, good thread 
Anyone have location/explanation photos similar to the OP? All of his original photo links are dead. Does the LSPV type/location differ from year to year, I have a 1995 and think I need to do this adjustment. Thanks for any help!
It's right here.
Thanks, that's perfect.
The amount you lower the LSPV valve down the frame and/or adjust the nut at the axle depends on your individual lift. It takes some tweaking to get it right without multiple brake pressure gauges. For a 2.5" to a 3" lift I would recommend starting with a 1/2" drop of the valve on the frame (I accomplished this by using nuts as spacers between the frame and the valve) and then tweaking the nut at the axle starting from the bottom. The higher you raise the nut at the axle the more brake force is applied to the rear wheels.
If you don't have a lift, I don't think you'd need to mess with anything except adjusting the nut at the axle.
If you don't have a lift, I don't think you'd need to mess with anything except adjusting the nut at the axle.
