Outer Limits 4x4 Board

I have told there is a few modifications to do to the braking system in the GQ to get the rear Disk Brake Conversion to work properly.

Can anyone tell me what it is ?

I will be buying a new Master cylinder but what else do you need to do to make it work ?

Cheers Nick

you need to also get the rear proportioning valve that comes off the rear diff to prevent the rear brakes locking up when there is no load in the rear of the car

Is that the bit that has a spring attached to it and a little hydrolic cylinder ?

I am assuming that the drum and disk one is different ?

Sorry for being a bit of a noob about it but don't want to stuff up the brakes trying to do it.

Thanks for the help

Nick

yes it is the spring. would you like a picture?

perportioning valves are the same as far as i know. drum rear have a smaller master that is all. I do not run the perpotioning valve as when 4 wheeling if doin steep down hills it reduces rear braking.
The valve has a bypass circuit that re-routes the fluid to the front, the perportioning part works from the leaver setting the valve position and also a ball floating when under brakes to adjust the valve position for more rear bias.
I priced new ones 4 years ago GU $580 GQ $730, I was told at a brake shop they are not successfully rebuildable.
The GU has the bolt holes tapped into the valve n GQ has through holes n tapped chassis.

When you removed the bias valve did you just disconnect the whole line back to the front ?

I like the idea of getting better braking on the rear for 4wding.

Thanks for the help nastytroll, I appreciate it.

Cheers Nick

tna racing wrote:yes it is the spring. would you like a picture?

That would good thanks mate

I ran the brake line straight from the master to the flex line. this may not be leagal as it is a brake modification, so if this is relevent to you check with your local DOT

don't remove the proportioning valve, just tighten up the lever all the way shut with the adjusting nut.

I usually use a peice of 6mm threaded rod n a nyloc nut, my valve was RS so just removed it.

gorilla wrote:don't remove the proportioning valve, just tighten up the lever all the way shut with the adjusting nut.

I'm assuming that means winding it all the way in ?

Just want to make sure.

Cheers Nick

Yep, thats what i did and the brakes are 100% better, i converted my ute to a disk rear end, kept the standard master cylinder and would the proportioning valve all the way in.

If you haven't already bought the master cylinder the try it and see first, the only difference is the disc master cylinder pushes more fluid to the rear.

Cheers

Chris

I've got front 60 series Land Cruiser disks that I plan to use to replace the drums. What have you guys used ?

Mario wrote:I've got front 60 series Land Cruiser disks that I plan to use to replace the drums. What have you guys used ?

I'm using a complete patrol rear disk brake diff from a GQ.

Cheers Nick

I used Y61 rear end, have also used Y60 rears. Standard patrol disks just slide over the studs so are easy to use for conversions on drum rear n just make your own caliper braket to suit the calipers you use.

I would recomend changing the master, the extra difference is worth it.

nastytroll wrote:I used Y61 rear end, have also used Y60 rears. Standard patrol disks just slide over the studs so are easy to use for conversions on drum rear n just make your own caliper braket to suit the calipers you use.

I would recomend changing the master, the extra difference is worth it.

Thanks again champ.

Owe you a beer

gorilla wrote:Yep, thats what i did and the brakes are 100% better, i converted my ute to a disk rear end, kept the standard master cylinder and would the proportioning valve all the way in.

If you haven't already bought the master cylinder the try it and see first, the only difference is the disc master cylinder pushes more fluid to the rear.

Cheers

Chris

Is there only one screw that can be screwed in?

I wouldn't mind trying this before i fit my new master next week.

dwaynes wrote:

gorilla wrote:Yep, thats what i did and the brakes are 100% better, i converted my ute to a disk rear end, kept the standard master cylinder and would the proportioning valve all the way in.

If you haven't already bought the master cylinder the try it and see first, the only difference is the disc master cylinder pushes more fluid to the rear.

Cheers

Chris

Is there only one screw that can be screwed in?

I wouldn't mind trying this before i fit my new master next week.

Yes, it is a bolt that goes through the lever arm and into the body of the proportioning valve, winding it all the way holds the lever across, giving the rear brakes as much fluid as possible, and it can be undone if you even need to go over the pits.

Sorry to bring this up again but are the brake lines differant ?

Going to be putting it in this weeken and I'm just sorting it all out in my head.

Thanks for all the help.

Nick

brake lines are the same.

Thanks mate