Brake proportioning valve adjustment

[gqjoey]

Lift is as the same as when I've got it and brakes only stopped working when I fitted new pads and rotors (x4).

Thanks billsgu and yes I've have bled all corners Including the lsv more than once. Fluid is solid all round.

However I can stall the engine if I push that bolt above the stopper bolt in and hit the brakes. (Lengthening the spring) though I thought it was supposed to be the other way around ?



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[Throbbinhood]

Am I right in assuming that when you go higher in lift without the bracket, you will lose brakes at the rear? Or will braking at the rear increase?

I currently have a 3" lift in mine. Was told by the reputable 4x4 shop when it was put in that it's not need for a lift of this height, and as such have no bracket. Braking isn't bad, but as with anything, if it can be improved, why not.

Bump, anyone know the answer to this?

[BillsGU]

Bump, anyone know the answer to this?

Yep - that's the way I understand it. If you put more weight in the back - the back goes down - the LPV applies more bias to the rear brakes. If you put a lift in - there is more clearance between the chassis and the rear diff - so it would be the same as the Patrol being unloaded as far as brake bias is concerned - therefore you need an extension on the bracket to bring adjustment back to the norm.

[Throbbinhood]

Yep - that's the way I understand it. If you put more weight in the back - the back goes down - the LPV applies more bias to the rear brakes. If you put a lift in - there is more clearance between the chassis and the rear diff - so it would be the same as the Patrol being unloaded as far as brake bias is concerned - therefore you need an extension on the bracket to bring adjustment back to the norm.

Thanks mate, guess I'd better make up a bracket then

[Throbbinhood]

Just wondering, when you put weight in the back of the car, does the spring tighten or loosen? As in, does that lever move towards the passenger side, or towards the driver side, and which way gives more rear brake bias?

Also, anyone know where to get a replacement spring for it? Mine measures 195cm. I've used a couple of zip ties to get it back to 178cm in the meantime.

[Rock Trol]

Am I right in assuming that when you go higher in lift without the bracket, you will lose brakes at the rear? Or will braking at the rear increase?

I currently have a 3" lift in mine. Was told by the reputable 4x4 shop when it was put in that it's not need for a lift of this height, and as such have no bracket. Braking isn't bad, but as with anything, if it can be improved, why not.

Even for a 2-3 inch lift you will lose some braking from the rear. You may be able to get enough adjustment from the standard set up to get the brakes just right but with a bracket it is much easier. I had bugger all brakes at the rear after my lift but after I installed a bracket I was able to adjust the brakes correctly. Takes a few attempts though until you get it right. Too much bias to the rear and you lock up brakes as well.

I think the bracket was worth every cent ($32 delivered) as you can really set it up to brake like a stock Patrol.

[Throbbinhood]

Even for a 2-3 inch lift you will lose some braking from the rear. You may be able to get enough adjustment from the standard set up to get the brakes just right but with a bracket it is much easier. I had bugger all brakes at the rear after my lift but after I installed a bracket I was able to adjust the brakes correctly. Takes a few attempts though until you get it right. Too much bias to the rear and you lock up brakes as well.

I think the bracket was worth every cent ($32 delivered) as you can really set it up to brake like a stock Patrol.

I installed the bracket yesterday. See post above about the spring.

[Rock Trol]

I installed the bracket yesterday. See post above about the spring.

From memory when you open the lever it sends more pressure to the rear. Closing the leaver restricts the pressure so there is less braking. I have noticed that different model years have the brackets mounted in different ways and maybe the valves themselves are different. For instance the set up on my 2007 model is slightly different to a mates 2004 model. What you need to do is get the spring in a horizontal position and then look at what would happen if the rear is lowered. Normally the spring will open the lever (from memory). It does not take a lot of adjustment on the lever to change the bias. It's a lot of trial and error. Try adjusting the lever so that its in the middle of the range of movement that it has and then drive it to see what it does.

[Throbbinhood]

Can anyone confirm the measurement for a GQ? I've seen 175-178 listed here, but think it may be for a GU. Have seen 207-220mm listed elsewhere.

[FrodeS]

My car: 1993 Patrol Y60 2,8 turbo diesel SWB. Euro. 2" lift. (guess you call it GQ)


When the car raises in the rear, tension on the spring DECREASE, and so does the braking pressure. When the brake pedal is applied, the valve is pushed outwards, increasing tension on the spring. If the spring does not hold it back, pressure to the rear brakes are cut of. The more tension on the spring, the more brake.

I will alter the bracket on the differensial, making it higher and adjustable. I do a lot of heavy towing, and optimum braking balance is important.

The spring sits at an angle from the differensial, down to the valve on the right hand side. It flats out when the car is lifted, and causes less tension / less braking.