Brake balance: front to rear and left to right

[Shephead]

On wet roads i can all far too easily lock up when braking. Tyres have plenty tread left, but are about four years old and with 40psi, they are frankly dangerous - need to replace them soon.

Anyway on the matter of my brakes, when I deliberately or otherwise brake hard on wet road surface, the front left locks first (all too easily), then with a little more shove the front right locks. Not sure what happens after that, not game to try.

Why is the left getting more braking force than the right? Has new pads and rotors have recently (one month) been machined.

Is it possible the rear isn’t doing enough braking? I have a 2” lift and corresponding brake proportioning bracket.

Want to get this looked at before I end up in a ditch or worse.

Cheers

[mudski]

Sticking calipers mate. Time to rebuild them

[Shephead]

Sticking calipers mate. Time to rebuild them

Can you explain? Does that explain the left to right bias?
Cheers

[pollenface]

Is 40psi a bit much? I don't go over 30psi, stock tyre size.

[mudski]

Can you explain? Does that explain the left to right bias?
Cheers

Well if you have one caliper thats sticking, or not pushing the caliper pistons out at the same rate as the other side due them sticking it aint apply the same brake force. Hence the car pulling to one side when the brakes are applied. Could even be a dodgy brake hose. Who knows.

How old is the Patrol? When were the last time the calipers were serviced?

[Shephead]

Ah right, that makes sense.
It’s old enough! But serviced regularly. I’ll ask about the callipers next time. Cheers

[dpetersen]

Is 40psi a bit much? I don't go over 30psi, stock tyre size.

40psi is better than 30psi. Tyres will last longer, wear better and you’ll have more control of the car.


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[dads tractor]

Shephead I have a 21 year old Coily and live in Nth QLD I replace all fluids in it after the wet season and have no dramas oils are cheap and run DBA 2 slotted rotors. I spray brake clean on the brake componets (rotors ,disk and calipers )and inspect before I rebleed the system.She brakes pretty well!

[Shephead]

Shephead I have a 21 year old Coily and live in Nth QLD I replace all fluids in it after the wet season and have no dramas oils are cheap and run DBA 2 slotted rotors. I spray brake clean on the brake componets (rotors ,disk and calipers )and inspect before I rebleed the system.She brakes pretty well!

Mines only a teenager (17). We’re in lockdown again down here again (sigh) so maybe I’ll get the front wheels off this weekend and follow your lead. Cheers

[dads tractor]

That sucks to be locked down again but I'm thinking we may all end up in the same puddle,even though there were no cases after the Ruby debacle.

[AndyAnderson66]

Another factor that has accelerated brake wear (especially rear brake wear) in certain late model vehicles is the change to electronic brake proportioning. The proportioning valve that normally reduces hydraulic pressure to the rear brakes has been eliminated so the rear brakes will handle a higher percentage of the brake load and be more aggressive. The antilock brake system performs the job of brake proportioning by keeping an eye on how the rear brakes are behaving. If the rear brakes start to lock up when braking hard, the ABS system kicks in and cycles pressure to the rear wheels to prevent them from skidding🤔🚀🚘 (https://jeepequipment.com/best-rotors-for-jeep-buyers-guide/).

[Bobo]

I have similar but opposite issues.. rear is braking way to much and locks very quickly before the front did anything so it feels like.
Might replace the proportion valve.. Can somebody explain me why this is a 3-way valve? Where is the 3rd one going actually?

[mudski]

I have similar but opposite issues.. rear is braking way to much and locks very quickly before the front did anything so it feels like.
Might replace the proportion valve.. Can somebody explain me why this is a 3-way valve? Where is the 3rd one going actually?

Is the Patrol lifted? If so how high? Is there the spacer bracket to compensate for the lift? Have you ever bled the brakes? Bled the proportioning valve? And its not a 3 way valve, its two way. To the front and rear. The third line you see is the line in from the brake master cylinder.

[BillsGU]

Many of the LPVs are never bled from when the Patrol is built resulting in a build up of moisture and crud which destroys the piston. When you bleed the valve, have a look at the colour of the fluid that comes out. If it is black and cruddy you may have to remove the valve and see if the piston / bore will clean up. If not - get a new valve. As far as a lift goes, I thought it would reduce braking on the rear brakes (like running with no load in the back and the ride height high). That's why when you do a high suspension lift you need to replace the LPV arm with a longer one.

[MB]

You two Legends here above have just kindly reminded/educated me of yet another nuffy thing I do have to attend to on my current Shed Queen GU ute.
One of its last adventures down a gnarly staircase track the poor front axle had to take the entire weight of the truck nose balancing with the rear tyres barely on the track surface.
Only a 2” lift coil front and ‘on air’ coil replacement rear bags with Koni 90 shocks all round but found bugger all rear brake capability shortly after that hand stand effort IIRC. (Maybe it was the opposite brake loss way FR :-) ?
Found my springy off the proportiony rear valvey arm thingy had completely popped off from what I could only understand as severe over stretching.
I’m assuming my silly aftermarket current setup didn’t hold the rear axle back enough at OEM proportional valve area maximum allowances?

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[Franksy4]

Hi is it possible to put front brake callipers on to the rear without to much work as i have a brand new set of front callipers

[mudski]

Hi is it possible to put front brake callipers on to the rear without to much work as i have a brand new set of front callipers

No. Not possible. Different mounting bolt pattern, different brake pads, different size caliper pistons.