Well this has got me stumped ... has anyone got any suggestions ... I really don't understand properly how to adjust these after a lift and I want to get it right as the results could be drastic...

I have a 3" lift and my braking is less that satisfactory and after taking a friends 92 HDJ80 for a test drive yesterday I was surprised just how well his braked... he has standard disks and lift. Even though I got a big improvement after I installed a set of slots up front it is still poor compared to his... Which makes mine scary

Well this morning I went out and played again with the LSPV and by using all the adjustment wound it right out, after testing on gravel I still cannot lock the backs up but the brakes seem much firmer???? Is adjusting out a good thing?
In fact I just went for another test drive and I must say that I really think I have helped things as the brakes do seem much firmer, it is pissing down rain outside and even on a slow turn and braking hard the fronts locked but still the rears won't, so seems that I have not gone to far...??? They seem better close to my friends 80 now... time will tell... To me this means that I have increased the pressure to the backs but I am still not locking them..
I just happen to have a full trailer of timber that I will test the brakes again later this week as I did notice yesterday that when I was dragging it the 80 was reluctant to stop...

So what is the go how should these be adjusted and in which direction ... and how and by how much???
The below articles tell you about them and there purpose... but I want to know how should we(shouldn't we) adjust these LSPV's...

IH8MUD
http://forum.ih8mud.com/80-series-tech/ ... -what.html
Load sensing proportioning valves usually are adjustable, and must be adjusted correctly if they are to properly balance the rear brakes to the vehicle's load. The valve linkage is adjusted with the suspension at its normal height (wheels on the ground) and the vehicle unloaded. The adjustment bracket or linkage is then adjusted according to the vehicle manufacturer's instructions, which typically involves adjusting the linkage to a certain position or height.

Load-sensing proportioning valves are also calibrated to work with stock springs. Any suspension modifications that increase the load-carrying capability (installing helper springs, or overload or air-assist shocks, for example) may adversely affect the operation of this type of proportioning valve. Modifications that make the suspension stiffer reduce the amount of deflection in the suspension when the vehicle is loaded, which prevents the proportioning valve from increasing rear brake effort as much as it normally would. A defective proportioning valve, or one that is not properly adjusted, can also upset brake balance. If the rear brakes on a vehicle seem to be overly aggressive (too much pressure to the rear brakes), or the vehicle seems to take too long to stop (not enough pressure to the rear brakes), the problem may be a bad proportioning valve. Proportioning valves can be tested by installing a pair of hydraulic gauges (one on each side of the valve) to see if the valve reduces pressure as it should.

Below is a snip from an article from Sleeoffroad
http://www.sleeoffroad.com/newbie/newbie100.htm
5.8 Adjusting the brake proportioning valve after installing a lift kit

"Spent some time under the truck last night trying to figure out if there is an easy way to know how much you could lower the LSPV body to adjust the braking pressure after a lift. Basically, moving the end of the rod (the normal point) moves a rod 600 mm long. The point on the rod where the LSPV actually contacts is only 38 mm from the pivot. End result is that the movement at the end of the rod is 1/15.75 of the movement at the body.

So, if you've lifted your truck 75mm (after allowing for settling, etc.), you'd need to lower the LSPV body by 4.8mm to be in the right
ballpark. You can adjust the end of the rod roughly +/- 6mm, so you'd need to get the LSPV body within +/- 0.38mm to be able to make the final adjustment with the end of the rod.


I hope that helps someone who's going to do the lift. I wish I had thought about it before I moved everything around and lost a starting reference point." - Juice

It is all trial and error to how you want yours to handle.
The proportioning valve should be level either side as an estimate. Adjust it when your vehicle is carrying half the usual weight i.e fuel load, tools etc

Having it adjusted to the bottom will send most of your braking to the front.
Having it adjusted all the way to the top will send most to the rear brakes.
I think this is correct...

About 25% adjustment for front brake is where I like mine. Reverse down a slight hill, in the wet is a bonus, and hit your brakes. If the fronts lockup and the rears feel like they do very little then it is adjusted too low.
Do the same driving forwards down the hill and hit the brakes hard. Your tyres should be of almost equal traction before they start skidding. The front pulls up a little better and starts to loose traction in the rear, at the same time the front will start to lockup and by then you should be almost stationary.

Someone could probably give a better explanation...
It is good to get it right and keep regular checks on your brake pad wear.

Once you think you've got it right go for a drive and hit the brakes around a tight corner (sensibly), in the wet or on gravel, enough to see if in an emergency it is going to perform good enough to your liking.
As you have mentioned you have fitted a 3" lift, if you find you cannot get enough adjustment you may need one of these;
Proportioning Valve Bracket
It sounds like you have enough adjustment to play with though.

Funnily enough I fitted 20mm spacers to the rear of my 4" lift yesterday and had to adjust mine.
A bit of driving and fine adjustments along gravel roads and you should get there.

Have fun.

I just found a couple of posts on I8mud about this
http://forum.ih8mud.com/80-series-tech/ ... 5-ome.html
http://forum.ih8mud.com/80-series-tech/ ... tures.html

I just adjusted my LSV down 6mm today . I must say the difference to the braking is huge. Seems to have heaps more bite now
I would still like to check the setup, I was going to get it done by a brake mob but I dont trust any of the people in town to do the job so Im thinking of setting up myself with some pressure gauges and fittings to do the job, might see what the SST from toyota is worth

I also just adjusted mine down at the valve. Silly me didn't realise that the valve end was forward of the pivot... Dooh I had been mucking around at the other end....
Anyway after having a look at those links you guy's posted I was able to easily adjust mine and I also got a big braking improvement... Cheers..

I was struggling to get my head around how it would work when I first read about moving the LSV. I thought that front pivot was part of the valve for some reason which is why I couldnt figure out how it worked. Now that I've done it, its suddenly clear

So Shane I gather there is already sufficient length in the slotted hoels to get the 6mm adjustment without modifications.

Pete, Pete, Pete......... As a long term member of LCOOL I would have thought you'd know better.

http://www.lcool.org/technical/80_series/brake.html

Heeps - you could move it double that in either direction.

Im thinking about getting hold of the toyota pressure gauges to do this job properly, just havent had the nerve to call toyota yet

Easiest way is to move the whole assembly using the 2 bolts on the diff housing

After much reading I" don't think that is the case necessarily as moving at the diff end needs ot be 16 times longer than the movement at the LSPV end due to the leverage ratio on the arm. I was going to make a new extension bit but no point moving that end say 96mm when you only have to move the other end 6mm.

Check it out and see what works best for you. I moved the lspv downward slightly after lifting but it wouldnt budge more than 2-3mm. Took it for a spin and it wouldnt lock the rear wheels no matter what I did. Moved the diff bracket up and now she locks all 4 and brakes whilst still being biased toward the front.