Drum to Disc Conversion

Cy · Post by Cy » April 15th, 2006, 5:42 am

I must say...

I didn't do the rear disc brake conversion because people were all talking about how you had to replace everything out back and whatever....
I instead replaced all the parts that wear on my Drum setup..which i'm totally happy with...

But a friend of mine just baught a GS and i made him new lines from the front distrobushion block to the rear discs... and while i was under the car i noticed a few things...
-) the forward and trailing control arms are identical to those of the RS
-) the shocks while having an ABS sensor etc. are exactly the same (which wouldn't matter as the RS doesn't have ABS)
-) the performance rod and bushing are all the same and in the same place...
-) the spindle looks hell of a lot like the RS one.. for bolts matching up at least

SOOOOOOo..... todo the conversion your talking remove the drum spindle(which may or may not be EXACTLY the same) mount the hardware... replace the flex lines and go...

Even if i didn't have a shop full of air tools, jacks and stands...
All you'd need is..
- A strong arm and a 3/4 inch drive 1-1/4" Socket(spindle nut)
-21,19,18,17,15,14,12,10,8mm sockets and a 4 inch extension.. And preferably 2 ratchet wrenchs.. because you'll need Two 15,17,19mm's(lower shock bolts...)
-8mm wrench for bleed screws..
-And the page with the tourque specs on the lower control arms, shock tower, and brake nutz and bolts...

I don't know if the piston Gross area is different.. but i doubt it is enough to need a new master cylinder and or Brake booster assembly...

If you didn't have a clue.. it'd take you 2 or 3 afternoon's maybe...I've taken apart my suspension like 5 times now while putting it together..so anyone who's done something like that before could do it in a day...

<END RANT>

rusty · Post by **rusty** » April 16th, 2006, 2:23 pm

I have done this conversion and let me tell you it's not as dificult as everyone told me. The master cylinder was the same and doesn't need changing. What you need to do this conversion is the spindle off a MX3 with rear disc brakes from the V6 model, Calipers, new flex lines, parking brake cables. Thats IT

Cy · Post by Cy » April 16th, 2006, 2:51 pm

that's what i'm saying...

if you have enough mechanical knowledge to change your own brake pads you can probably do this...

Steeb · Post by **Steeb** » April 16th, 2006, 7:13 pm

i believe the master cylinder and brake booster is different on the gs also. im not sure if brake booster is what that big black thing is called... correct me if im wrong.

Cy · Post by Cy » April 16th, 2006, 9:18 pm

i'll check tommorow

MAPEXMX3 · Post by **MAPEXMX3** » May 29th, 2006, 11:46 pm

HELLO...im doing it rate now on my mx-3..switch for drum to disc...a go a 91 protege rear end...and im aving a big time fun with the lower bolt..the longest one and the.i wont come out one...do you have a good tip for me...

Cy · Post by Cy » May 29th, 2006, 11:57 pm

MAPEXMX3 wrote:HELLO...im doing it rate now on my mx-3..switch for drum to disc...a go a 91 protege rear end...and im aving a big time fun with the lower bolt..the longest one and the.i wont come out one...do you have a good tip for me...

Oxy-Torch... If you want to save the drum spindle then do the following otherwise just cut it all out...

If you can... with the spindle still on the car heat up the 2 lower parts that the bolt is going through until they're RED hot... this will require even movement across both spots with the torch.. Then use a impact wrench to break the bolt loose of the rust.. and use a smaller diameter shaft to hammer out the bolt

I had todo the next part...and could because my Lower control arms were garbage..

Cut out the bushings (Wear A SWEATER and pants and goggles)
Cut the head off the bolt (i got the nut off)

Then pull out the drum spindle with the bolt still in it out..
Put the strut mounting end in a vice and heat up the spots with the torch..
Once it's glowing you can use a socket-wrench and a hammer to twist and pull the bolt out..

Vice-Grips are your friend

Steeb · Post by **Steeb** » May 30th, 2006, 4:01 am

Cy wrote:i'll check tommorow

i already looked at my friends rs mx3 and its not the same.

if anything, i would rather see if there is a better upgrade than the mx3 gs master cylinder, maybe a rx7 or 929 master cylinder or something. the master cylinder will make the most difference to displace more fluid.

Cy · Post by Cy » May 30th, 2006, 6:22 am

Steeb wrote:
Cy wrote:i'll check tommorow
i already looked at my friends rs mx3 and its not the same.

if anything, i would rather see if there is a better upgrade than the mx3 gs master cylinder, maybe a rx7 or 929 master cylinder or something. the master cylinder will make the most difference to displace more fluid.

upgrading without proper attention is BADDDDDDD

Master cylinders are made for the brake system they're attached to.. they have balancers in them

anything upsetting that is not good

Steeb · Post by **Steeb** » May 30th, 2006, 2:57 pm

i thought the master cylinder displaces the fluid moved by the pedal and the distribution block controls a set brake bias. a larger master cylinder will improve brake pedal feel because it displaces more fluid in the same amount of pedal movement. this creates more pressure at the calipers with less pedal movement.

a brake proportion valve would be what changes the brake bias for the front and rear..

i believe probe/mx6 guys use the rx7 or 929 master cylinder as an upgrade to improve pedal feel.

edumacate me if i am incorrect. ive never learned about what each part in the brake system does exactly but i have an idea of how the brake system works cuz i did a complete mtx to atx swap and a full brake system refresh myself.

i think im gonna start a new thread about this but i am sure that the rs and gs do not share the same master cylinder.

Bochek · Post by **Bochek** » May 30th, 2006, 3:02 pm

yes the Master Cylinders are differet, the one from the GS has a bigger bore. Thus it moves more fluid at a lower pressure then the one from the RS

SO what this means is:

with rear disk's from a GS and the MC from a RS you will push the peddle farther, but have more breaking force applied to the calapers (less vollume more pressure)

The greater pressure is caused by the smaller bore of the MC. if you dont understand look up how hydrolic rams work.

Bochek

Steeb · Post by **Steeb** » May 30th, 2006, 3:11 pm

tight, i always like it when people younger than me know their facts. never underestimate people younger than yourself

Bochek · Post by **Bochek** » June 1st, 2006, 6:31 pm

so this means that the best break setup will be the rear discs with the RS MC.

Sounds like i got a conversion to do

Bochek

cjthor · Post by **cjthor** » June 1st, 2006, 7:09 pm

I have all the parts minus discs if anyone wants to do the swap.

Bochek · Post by **Bochek** » June 1st, 2006, 7:22 pm

id buy them as i am getting discs, but your too far to warrent the shipping costs.

Bochek