2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Having a hard time getting brakes to feel normal.

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Old 10-13-13 | 05:55 PM
  #76  
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Lol well thats no good. Id hate to blow a front brake line on an RX7. Well its not like that ever happens anyway, 9/10 its the lines going to the back that rot.
Old 10-14-13 | 01:21 PM
  #77  
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the order isn't super important, i do the rear first because it has more likelihood of getting air back into the system and having to start over, the rears taking the longest to bleed properly.
Old 10-14-13 | 01:48 PM
  #78  
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From: https://www2.mazda.com/en/100th/
Originally Posted by RotaryEvolution
the order isn't super important, i do the rear first because it has more likelihood of getting air back into the system and having to start over, the rears taking the longest to bleed properly.
my favorite is the left front, because its the shortest...
Old 03-15-14 | 11:16 PM
  #79  
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I'm having similar issues with my brakes.

Bought a shell; brakes were ****. Guy said it was cause he replaced something.
I bought different rear calipers + put those one.
Bought a new (reman?) MC cause old one was leaking.
Power bled with a motive power bleeder + custom cap.
Brakes still feel like sloppy ****. I probably will have to get another reman MC

But my booster does have a good amount of rust on it. I'm wondering if it leaks?
Old 04-02-14 | 08:17 AM
  #80  
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If you have no clear leaks on your calipers, more than likely they are OK. I changed mc's twice and put new front calipers on and still had crap for brake pressure. I will give you same advice as clokker gave me.
Get a matching booster and mc. I was in denial my booster was bad but as soon as I replaced the booster it bled super easy and my brakes worked.
Old 04-02-14 | 02:30 PM
  #81  
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What year Subaru did you get the MC/Booster from. My 86 Base brakes work, but could be alot better. Always thought there was a lot of pedal travel. Just thought it was normal for the single pot brakes.
Old 04-02-14 | 07:42 PM
  #82  
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Originally Posted by HRnico
Always thought there was a lot of pedal travel. Just thought it was normal for the single pot brakes.
Nothing to do with the calipers, everything to do with master cylinder size.
Old 04-02-14 | 10:08 PM
  #83  
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There are lots of subaru in the salvage yards around here. Infact way to many on the roads as well
Old 04-02-14 | 10:43 PM
  #84  
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Early 90's Subaru legacy. It has a cylinder shaped reservoir and aluminum 1 1/16"(iirc) mc. The size is on the mc somewhere.
Old 04-03-14 | 12:32 AM
  #85  
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Your pics in post #68 show the stamping indicating cylinder size.
Old 05-09-14 | 09:27 AM
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How's the MC/Booster swap working these days? Did the mounting bolts line up on the firewall? Are you able to use the FC proportioning valve? I'm going to the salvage yard this weekend and there are no FCs around here
Old 05-09-14 | 09:55 AM
  #87  
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My swap(s) all work well.
The Honda, Nissan and Subie swaps I detailed all bolt in, no firewall modification required.
Yes, you can use the stock prop valve.
Old 05-09-14 | 09:57 AM
  #88  
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A few suggestions:

1) Brake pads. What brand/Age/Wear
- Some pads use softer material than others. This leads to a soft feel. If they are worn unevenly same thing.

2) Brake pad shims. Do you still have the stainless steel and rubber shims?
-Sometimes the rubber shims rust creating a soft feel. Try pulling everything off so it's just the back plate

3) Does it ever feel firm? If you pump it 3 times and hit it does it feel good?
-This could indicate the pistons are "rolling back" a little too far
-During cornering, especially with opposed piston calipers, the rotors will deflect and push the pistons back into the bore. Next time you hit it, it's soft and comes back when you hit again. Sometimes race car drivers experience this and have to double pump before coming into corners to make sure brakes are there.

4) On the rear calipers I found my had a two bleeders on each caliper.

5) Rear caliper piston adjusters may not be working. Try pulling up on the hand brake a little at a time and see how it feels at the pedal. You will get some change, but this will give you an idea if the softness is in the front or rear. In my old truck with rear drums, if the rear was off just a little bit the pedal was total crap.
Old 05-09-14 | 11:09 AM
  #89  
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From: https://www2.mazda.com/en/100th/
Originally Posted by clokker
My swap(s) all work well.
The Honda, Nissan and Subie swaps I detailed all bolt in, no firewall modification required.
Yes, you can use the stock prop valve.
additionally all of the Mazdas use the same pattern too, except that the FC uses really long studs to mount the booster, and all of the other mazdas have shorter ones.
Old 05-10-14 | 01:23 AM
  #90  
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Clokker, could you post up a link to one of your swaps? I've tried searching, but you have alot of posts.

Thanks cbrock, I'll run through your check list when I get the back on the road.

Last edited by HRnico; 05-10-14 at 01:25 AM. Reason: More is Better
Old 05-10-14 | 05:43 AM
  #91  
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Why yes I can...
Old 05-10-14 | 09:05 AM
  #92  
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^
Wrong subject.
This is about brakes...
Old 05-10-14 | 11:20 AM
  #93  
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i had just finished deleting my abs a few months ago. while i had things apart i figured may as well rebuild all calipers. got it all done and back together, bled it thoroughly, pedal felt like ***. drove it for a bit like this, and noticed after a few weeks it firmed up to the point that it feels good and solid. i have noticed this with other cars i've done brake work on as well. bled it. bled it again. and again. same results. drive for couple weeks, pedal feels great again. unfortunately i don't have a reasonable explanation for this. i just know it's been the case for several of my cars.
Old 05-10-14 | 08:06 PM
  #94  
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Air in the system working it's way to the MC and escaping via the reservoir.
That would explain the time delay.
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