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I'm interested in a rear disk brake conversion for my 03 TJ. I have an aftermarket G2 Dana 44 in it, with 15" wheels, 33" tires. I've looked into the G2 and Teraflex kits. Has anyone done this modification? How do you like it? Was it worth the money? Did you have any problems? What are your recommendations?
 

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I have a set of discs off an explorer on the back of mine and am very happy with it. I hate drums with a passion esp on the jeep as the self adjusters don't. I would have to be back there messing with them all the time. I could tell when they needed adjusting because my pedal would lose some firmness. Does it stop any better? I think it does, a little at least but but for me it's A: I never have to adjust them again, and B: my pedal stays the same firmness all the time. Now I didn't pay the $500 those kits run but I am very happy with the results.
 

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Abe Froman
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Do a little searching on this as many people have done the conversion, but everything I have heard the braking is not improved or very little. I think you could spend the money elsewhere and get more bang for your buck. I do agree on the ease of maintenance though. That would be the only reason I would do it though.
 

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It does seem like a waste of money but to each his own. The rears only do 20-30% of the braking so the shoes last a long time. I did my drums last weekend and the shoes had tons of life left after 60k miles. I replaced the shoes anyway because the stockers have a groove down the middle for whatever reason. It was around $70 for new drums and shoes...you would never break even between the cost of a conversion and a $70 brake job every 100k miles.
 

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Why do you want to convert to rear disks? If it's for easier maintenance, that's a valid reason. If it's for better braking, improve your front brakes instead. Converting from drum to disk in the rear will not help your braking. In fact, the rear brakes are limited in how much braking power they provide by the brake proportioning valve to keep them from locking up and causing a skid in heavy braking. Rear brakes aren't braking as hard as they could, due to the brake proportioning valve, so the conversion to disk in the rear would provide no noticeable braking performance improvement in normal braking. Better rear brakes will only help when you are driving in reverse or backing down something.
 

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Why do you want to convert to rear disks? If it's for easier maintenance, that's a valid reason. If it's for better braking, improve your front brakes instead. Converting from drum to disk in the rear will not help your braking. In fact, the rear brakes are limited in how much braking power they provide by the brake proportioning valve to keep them from locking up and causing a skid in heavy braking. Rear brakes aren't braking as hard as they could, due to the brake proportioning valve, so the conversion to disk in the rear would provide no noticeable braking performance improvement in normal braking. Better rear brakes will only help when you are driving in reverse or backing down something.

Or you can change the proportioning valve to a disc to disc valve which equals the pressure. Works great!
 

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Or you can change the proportioning valve to a disc to disc valve which equals the pressure. Works great!
Jeep uses the exact same proportioning valve in the tj for drum and disk brakes. And for the reason already given above, equalizing the front and rear braking pressure will cause skidding. And if equal f/r pressure worked, which it doesn't, brake proportioning valves wouldn't be needed.
 

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Jeep uses the exact same proportioning valve in the tj for drum and disk brakes. And for the reason already given above, equalizing the front and rear braking pressure will cause skidding. And if equal f/r pressure worked, which it doesn't, brake proportioning valves wouldn't be needed.

That's probably why you use an adjustable valve, I did and lord behold no skidding.
 

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Or you can change the proportioning valve to a disc to disc valve which equals the pressure. Works great!
I have a wilwood adjustable prop valve
That's probably why you use an adjustable valve, I did and lord behold no skidding.
I'm confused, you recommend a disc/disc combo valve and that is already what is in the TJ as there is no difference in the combo valves in the 97-03 combo valves whether the rig came equipped with rear drums or rear discs.

Then you say to use a Wilwood adjustable which is not a disc/disc combo valve so that makes it sound like you put in a disc disc valve and then added an adjustable to the system?

Can you clarify that a bit further?
 

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It does seem like a waste of money but to each his own. The rears only do 20-30% of the braking so the shoes last a long time. I did my drums last weekend and the shoes had tons of life left after 60k miles. I replaced the shoes anyway because the stockers have a groove down the middle for whatever reason. It was around $70 for new drums and shoes...you would never break even between the cost of a conversion and a $70 brake job every 100k miles.

That groove is to reduce the effectiveness of the rear drums slightly to stop them from locking up since Jeep uses the same combo valve up to and including 03 when rear discs started.

It wasn't until the Unlimited started that they added another one to the parts list.
 

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I'm confused, you recommend a disc/disc combo valve and that is already what is in the TJ as there is no difference in the combo valves in the 97-03 combo valves whether the rig came equipped with rear drums or rear discs.

Then you say to use a Wilwood adjustable which is not a disc/disc combo valve so that makes it sound like you put in a disc disc valve and then added an adjustable to the system?

Can you clarify that a bit further?
That's what I did, I installed an aftermarket prop valve that was installed at the master cylinder (disk to disc) which actually isn't equal pressure. Then I installed an adjustable prop valve inline for the rear brakes only to fine tune the pressure (around 65/35) no problems.
 

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Or you can change the proportioning valve to a disc to disc valve which equals the pressure.
That's probably why you use an adjustable valve...
I don't use and never have used an adjustable valve. And once again, you do NOT want equal front/rear brake line pressure which would only cause the rear brakes to lock up prematurely and cause skids. Even stock drum brakes have FAR greater braking potential in the rear than can be allowed to be used without skidding... which is why there is a brake proportioning valve in the first place... to reduce how much braking the rear brakes are allowed to perform.

So improving how well the rear brakes can brake is pointless in normal braking situations... they already have the potential to brake harder than they can be allowed to.
 

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I don't use and never have used an adjustable valve. And once again, you do NOT want equal front/rear brake line pressure which would only cause the rear brakes to lock up prematurely and cause skids. Even stock drum brakes have FAR greater braking potential in the rear than can be allowed to be used without skidding... which is why there is a brake proportioning valve in the first place... to reduce how much braking the rear brakes are allowed to perform.

So improving how well the rear brakes can brake is pointless in normal braking situations... they already have the potential to brake harder than they can be allowed to.
I DON'T have equal line pressure because of the adjustable prop valve, and as I said the disk on disk prop valve is NOT a 50/50 pressure valve anyway. I do know my system works excellent, I change front pads 2 to 1 over the rear. You may be an expert but I know what works!!
 

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I DON'T have equal line pressure because of the adjustable prop valve, and as I said the disk on disk prop valve is NOT a 50/50 pressure valve anyway. I do know my system works excellent, I change front pads 2 to 1 over the rear. You may be an expert but I know what works!!

You need to go back and read what you are telling folks to do. First you imply that going to a disc/disc combo valve is the way to go and then you go on to tell them that you need to reduce the pressure further out of that with an adjustable prop valve in order to keep the rears from locking up.

Had you just left it alone, provided it is a TJ combo valve, you would enjoy exactly the same results you have now with less money spent, no new lines being made, and less complexity in the system.

BTW, I'm not familiar with your particular disc/disc combo valve, but most of them are split 50/50 front to rear because there is no need for a knee point in the pressure output to stop the servo nature of the rear drums.

Drum brakes past a certain pressure point are self applying which is also why they have very high force return springs. Due to the self applying nature, the pressure is cut off at a certain point and stays there to stop them from locking up.

Bias in a disc/disc system is done by the size of the components. The rear caliper is typically 50% smaller and the rotor is much thinner, non vented and the pads are very small when compared to the front.

I'm also not sure what you meant by 65/35. All aftermarket adjustable prob valves are only capable of reducing the pressure by 60% which means I can't tell from the way you wrote it if you are using it at 35% or 65% and I'm assuming it must be a 35% reduction because it won't go 65%.
 

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You obviously don't know what your dealing with here....
 
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