Raised rear = adjust load valve

[oldrev]

Ok i thought i might air my ideas on this subject just so i can be called mad or whatever.
i've read most of the posts on this issueand a couple of them have touched on what i reckon might be the problem.
even though i have not mucked with the rear of my ute as yet ive had it loaded to the gvm @ least a few times and the most recent was up to lcmp loaded to 2540 over the scales thanks to camwill69 for the weighin.
at no time did i feel lacking in brakes .
i came home similar weight less beer and fuel.
yes the truck felt like it was dragging it's a.se but i believe its because of this that the correct bias to the rear brakes was at.
i'm thinking that the lpvalve is in sinc with the original spring rate.
as soon as we put in all the heavy springs, air bags, etc to stop it sagging in the rear i think it is upsetting the rate that the lpv adjusts.
i think there needs to be something else adjusted not just the length of the rod.
please shoot me down in flames because i have to go through this myself @ sometime soon.
regards to all in this thread
ken

[mblux]

hi guys
on this brake proportion valve issue i have done on road and kpa pressure testing releting to thisissue i found with the rear of my truck raised app 55 mm the pressure at the front calipers was 9000kpa and the rear with standard prop valve height was 300 it should be around 5000 so by raising the valve approx 60 mm which was not possible with out making adapter to the rod i was able to get 5250 kpa whiich has improved braking out of sight my measurement from bottom centre bolt to top adjuster is now 215 mm . i have second stage manufacture facility and do gvm upgrades every week proving these figs with all test equipment . saying that i have had my own shit brakes for 12 months only recently in last two weeks actually fixing them , dont know why it took so long but now it stops great cheers mark

[david allan]

hey mblux
you say you have a 50mm lift from standard & by extending the bolt you have fixed your brakes.
How much did you actually extend the original bolt by.

I got the OME med rear ones and have reversed the nut making the small nut on the top and winding it all the way to the top. So there is no more adjustment left for me without extending the rod.
Im thinking about extending it still.

For interest mate what is your suspension measurment from bottom of rim to bottom of guard with 15inch rim.

How did you test the pressure in kpa's

[mblux]

hi
my original rod lenght to adjuster was 160 mm i now have it at 215 mm used an extra nut 8mm a rod extender nut 8 mm which is app 25mm long and 30 mm piece of threaded high tensile rod and a lock nut . i will email you a pick if you require . my bootom of rim to guard is 840 mm i have 16" rims . testing kpas is done with brake pressure testing equipment , 2 x gauges and braided lines we remove bleed screw s and have fitting s to go in there and hook up to gauges , they have a bleed nipple so bleed brakes thru gauges and presto you have relative pressures std for disc front 9000 rear drum between 4800-5800 rear disc 7500-8500
you push on pedal until you reech 9 on front gauge and then site rear gauge for ??? to adjust preesure raise or lower prop valve according ! cheers hope this helps if any more needed email me and ill give you my no

new to forum i assume you can email me thru here ???

my brakes were sh#t now they are great mark

[Quinny34]

Just got mine sorted and I can't understand why I didn't do it sooner.... The front rotors and pads have been leaving crap all over the front rims, not to mention to poor stopping...

$10 or less in parts.... A dirt road for tuning.... (Set to lockup slightly with no load on a dirt road)
2 8ml nut,
1 8ml nylock nut
1 50ml bolt
All able to easily be removed if I take the lift blocks out...

[mblux]

what he said above i have done all the tech tests and come up with the exact fix pictured above as mentioned earlier post

cheers for the photo

mark

[Rich]

Quinney23,
just out of curiousity, did you happen to notice how much more vertical movement upwards your rod has left now (further from its new raised height)?

I am curious because i don't think my rod can even be raised by as much as you have done and I think I could have a problem. I am trying to get my brakes working well and I have been playing around for some time now.

I have a 50mm OME ARB lift with medium springs.

Also, is that just an ordinary 50mm X 8mm bolt you have used to extend the rod?

thanks mate.

rich.

[Quinny34]

Still have veritical movement although I did try and bend the bar (with no success - had a beer instead)... the only issue it may have from my view is the angle of the connection has changed and is a little 'tighter' then normal... doesn't seem to stop it working...

For example, without the mod the linkage slides on and of easily, with the extenstion it sortof angles onto the bolt and requires it to be tightened before it sits straight... like I said, doesn't seem to cause issues and certainly helped... I probably should have used a 70ml length bolt as the adjust ment is nearly all the way up.

It shouldn't max out the upward travel though as long as you only extend it the same amount as the lift as the position should be relative to the dif in the same proportions...

Bolt is standard metric... no need for high tensile.. nuts are standard also with one nylock nut for saftey sake...

[Rich]

Thanks mate.

I will have to have another look at mine.

Rich.

[mblux]

guys be careful not to go to high with adapter because it will add a lot more pressure and the more weight you put in the back of the ute the more pressure is increased aswell causing the opposite to no brakes on rear / all brakes on rear and none on front ?? cheers mark

[david allan]

yeah mblux, your right
you dont want them to be to aggresive especially when you load it up.

Rich
are thinking about extending yours.

How much room is there actually on the normal bolt to extend the nut all the way to the top even if we reverse the nuts around.

I got mine tested by toyota, pressure test or something & they actually wound it down abit.
So i put it back up
I will do some tests on the weekend

[Rich]

Yes - I am thinking about extending mine. The latest picture above is the easiest method of extending it that I have seen so far, looks like it will be quick to do - and is easily removable if I want to take it off one day.

I want the ABS to kick in on the rear brakes as well as the front when braking hard (I will test it on wet bitumen roads).

At the moment, the front discs brake enough to activate the ABS but the rear does not. Leading me to think there is not enough braking bias on the rear.

When I step on the brakes in an emergency, I want the ABS to be working on all 4 wheels. Not only on the front and a 1/2 @rsed effort on the rear.

Rich.

[david allan]

Yeah Rich you are right

I think i have the same setup as you
Med OME in rear & have adjusted it all the way to the top & reversed the nuts around.

I remember you saying you had trouble in moving it above the original rod. You only had 20mm moveement
I will check mine on weekend & see how much more movement ther is

Rich
When you load the rear up & the rear drops, so you feel the brakes are working better

[Quinny34]

Just remember guys, if you have lifted your car say 50 ml... then you have moved the diff 50ml further down (give or take - angle of braket aside)

All this method is doing is moving the adjustment rod back to its orignal position... Each to there own but once you get under the car and have a look at the setup I think you will be more comfortable with what I and many others have done...

If you find it causes issues... (You will need to test on a quite bit of road) take it off... This method is easy to remove and does not modify the orignal components in any way... (like cuting and welding the rod for more length..)

[Rich]

David,
I have not really had a load in the back. 99 % of the time the back is empty with my truck (a light load such as the dog or a small 50kg load).

For the odd occasion where I do load it up, the ABS will stop the brakes from locking up and I don't mind paying for an extra set of rear brake pads occasionally if it means safer and better braking.

From memory - I think there was only about 30mm of upwards adjustment possible with the original rod (and that was with reversing the nuts), and my lift in the rear was 45 mm. So if my calculations are correct, I still have to lift it about 15 mm above the original rod to put it back to factory settings....

My problem could be in that I am restricted in the amount I can move it up, last time I checked it only had about 20 mm more height to go before maxing out - that is a concern for me. I don't want to be on the upper limit of the adjustment with an empty tray.

David, if you could unscrew yours and check how far higher the rod will go (above your standard rod) over the weekend, that would be great.

Quinny - thanks for your help also.

Rich.

[david allan]

rich
will do over weekend

If the max we can adjust it by reversing the nut is 30mm, then shoudl that not be enough.

Yes ARB claim to give a 45mm lift. But I dont have a 45mm lift.
If its was a 45mm lift then the rear would be sitting at 835mm in the rear.

From memory i think your was sitting 810mm. Is that right.
So that means you have adjusted it by 30mm while it is only 20mm above standard.
Am i on the right track

[Rich]

David, I am not sure what my standard height in the rear was before I got the lift. I just measured it again and its 805mm in the rear drivers side.

Does anyone know what a new un-modified hilux measures in the rear from bottom of rim to bottom of guard with the standard wheels?

ARB told me 45 mm lift in the rear, but they also said 30mm in the front - which didn't turn out to be correct.

What I want is for my rear ABS to activate when my front ABS does, so I am getting even and maximun braking on all 4 wheels in an emergency.

Personally, I think Toyota messed up with this whole LPSV in the SR 5 that has ABS.

[david allan]

stock standard SR5 with 15inch rim has a measurment of 790mm.
So it yours is 805mm then i dont see the reason to extend the rod.
You only need to adjust it by 15mm

[Rich]

Hmmmm.....I have raised the LPSV by more than 15 mm already - and still I have terrible braking in the rear.

Correct me if I am wrong, but if you brake hard on a wet slippery road, shouldn't all 4 wheels be locking up and the ABS engaging on the SR5, not just on the front?

Maybe we didn't read the fine print in the Hilux Specs, ABS on front brakes only.....

Or perhaps it says, Brakes on rear are notional only, do not rely on them....

I know you should not rely on your brakes anyway, but I still want them there as much as possible if I need them...

If someone steps / runs out in front of me, I want every chance of stopping and not hitting them as possible, as its probably only me who will have to live with the consequenses of bad brakes and have it on my conscience.

Rich.

[Rich]

I finally got around to doing this yesterday. I did it exactly the same as above...I have not had time to take it for a drive yet - should get to test it out with a drive today.
Need some rain to test it properly.

Rich.