After my little adventure this weekend with loosing the oil plug in the Brat, it got me thinking about a motor upgrade. Before I do a motor upgrade I need to do a brake upgrade. You know how it is if you have the go you will need to woooooooooo! My question is can I do a rear disk brake conversion and what do I need? I was told I could use a GL rear disk brake set up been told that I could not. I am not want to do anything special just add disk to the rear. I plan on running the stock rims so I not really want to do a 5 lug at this time.

 

What do I need to do this conversion?

 

Thanks.

Yes, you can swap rear disc brakes from a EA82. Most came on the turbo models and some were on GL-10 models. No proportioning valve needed.

Get the rotor, backing plate, caliper and rubber/hard lines and you will be good to go.

You just need to find a Turbo car either GL or XT with the rear disks...make sure they are from a 4wd..and pull everything..calipers backing plates rotors hard lines..

 

Its easy from there..should only take about 2 hours to do the first time..TheSubaruJunkie did a great step by step instruction page ..should be in the repair manual.

 

I have the parts here right now to do the swap on my 83 coupe..its FWD but its the same concept

Edited November 12, 200817 yr by Bucky92

http://www.ultimatesubaru.org/forum/showthread.php?t=49975

 

its simple.

take a can of PB Blaster and a wire brush to the junkyard with you.. the backing plates can be a PAIN to get off. Small sledgehammer too. Tap them to rotate them side to side while you pull on them.

thanks guys. I know know what to look for.

 

Just for S & G, if I was to do a 5 lug would all I need is a XT6 set up?

For the rear.. yes

 

For the front.. no.

Rear discs help to stiffen up a mushy pedal and they eliminate the need for manual brake adjustment. However they are not an "upgrade" that will help you stop faster with a larger engine.

 

Rear brakes only account for 25% of overall braking so assuming the rear discs are 50% better than properly adjusted drums (that's likely a vast overestimate) you are only going to get an additional 12.5% braking power. Coupled with the fact that you probably aren't going to install, test, and adjust a proper proportioning valve they may actually be MORE dangerous for high speed braking than the drums were - rear brake lockup while the fronts are still rolling is SCARY.

 

The rear brake conversion is nice from a maintenance standpoint. It's great for lifted rigs that won't see more than 55 or 60 MPH and helps to control larger tires, and it makes for a nice pedal feel and less nose-dive when doing everyday braking operations. It is NOT a replacement for proper brakes (IE 5 lug swap) when adding HP.

 

GD

Rear discs help to stiffen up a mushy pedal and they eliminate the need for manual brake adjustment. However they are not an "upgrade" that will help you stop faster with a larger engine.

 

Rear brakes only account for 25% of overall braking so assuming the rear discs are 50% better than properly adjusted drums (that's likely a vast overestimate) you are only going to get an additional 12.5% braking power. Coupled with the fact that you probably aren't going to install, test, and adjust a proper proportioning valve they may actually be MORE dangerous for high speed braking than the drums were - rear brake lockup while the fronts are still rolling is SCARY.

 

The rear brake conversion is nice from a maintenance standpoint. It's great for lifted rigs that won't see more than 55 or 60 MPH and helps to control larger tires, and it makes for a nice pedal feel and less nose-dive when doing everyday braking operations. It is NOT a replacement for proper brakes (IE 5 lug swap) when adding HP.

 

GD

 

I semi disagree with the part about them helping to stop faster...in my brat it made a huge difference! But maybe you experienced different?!

I semi disagree with the part about them helping to stop faster...in my brat it made a huge difference! But maybe you experienced different?!

 

The key is that most folks swap out the discs on a vehicle that had poorly functioning drums, or drums that weren't functioning at all (frozen adjusters, etc). If you repair the drums to the point that they function as designed (new drums, new shoes, new cylinders) then there is very little performance difference.

 

The disc's are awesome if you install a proportioning valve along with them. If you don't they are great right up till you try a panic stop on a slick surface. The rear end will pass you. Not really as cool as it sounds and it doesn't sound all that cool either.

 

GD

The proportioning valve issue has come up a lot.. I believe it to be a legitimate concern. You're basically looking at carrying over the same proportioning valve from the donor vehicle, right?

You're basically looking at carrying over the same proportioning valve from the donor vehicle, right?

 

That worked fine for my install, but to have truly accurate proportioning would require an adjustable valve. They aren't real expensive from Summit, etc.

 

GD