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

Having a hard time getting brakes to feel normal.

Thread Tools
 
Search this Thread
 
Old 10-13-13 | 05:55 PM
  #76  
MazdaMike02's Avatar
Mazda Tech
iTrader: (4)
 
Joined: Nov 2007
Posts: 1,589
Likes: 1
From: Tottenham, ON
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  
RotaryEvolution's Avatar
Sharp Claws
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 47
From: Central Florida
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  
j9fd3s's Avatar
Moderator
iTrader: (3)
 
Joined: Mar 2001
Posts: 31,203
Likes: 2,826
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  
incubuseva's Avatar
Boost knob
iTrader: (13)
 
Joined: Feb 2004
Posts: 1,716
Likes: 2
From: Lake Stevens
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  
junito1's Avatar
Thread Starter
F**K THE SYSTEM!!
 
Joined: Sep 2006
Posts: 2,588
Likes: 1
From: Florida
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  
HRnico's Avatar
Hooked

iTrader: (7)
 
Joined: Dec 2011
Posts: 402
Likes: 1
From: Hood River OR.
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  
clokker's Avatar
Cake or Death?

iTrader: (2)
 
Joined: Jan 2007
Posts: 10,249
Likes: 63
From: Mile High
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  
HRnico's Avatar
Hooked

iTrader: (7)
 
Joined: Dec 2011
Posts: 402
Likes: 1
From: Hood River OR.
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  
junito1's Avatar
Thread Starter
F**K THE SYSTEM!!
 
Joined: Sep 2006
Posts: 2,588
Likes: 1
From: Florida
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  
clokker's Avatar
Cake or Death?

iTrader: (2)
 
Joined: Jan 2007
Posts: 10,249
Likes: 63
From: Mile High
Your pics in post #68 show the stamping indicating cylinder size.
Old 05-09-14 | 09:27 AM
  #86  
HRnico's Avatar
Hooked

iTrader: (7)
 
Joined: Dec 2011
Posts: 402
Likes: 1
From: Hood River OR.
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  
clokker's Avatar
Cake or Death?

iTrader: (2)
 
Joined: Jan 2007
Posts: 10,249
Likes: 63
From: Mile High
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  
cbrock's Avatar
Rotary Enthusiast
iTrader: (1)
 
Joined: Aug 2001
Posts: 982
Likes: 0
From: MI 48111
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  
j9fd3s's Avatar
Moderator
iTrader: (3)
 
Joined: Mar 2001
Posts: 31,203
Likes: 2,826
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  
HRnico's Avatar
Hooked

iTrader: (7)
 
Joined: Dec 2011
Posts: 402
Likes: 1
From: Hood River OR.
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  
clokker's Avatar
Cake or Death?

iTrader: (2)
 
Joined: Jan 2007
Posts: 10,249
Likes: 63
From: Mile High
Why yes I can...
Old 05-10-14 | 09:05 AM
  #92  
clokker's Avatar
Cake or Death?

iTrader: (2)
 
Joined: Jan 2007
Posts: 10,249
Likes: 63
From: Mile High
^
Wrong subject.
This is about brakes...
Old 05-10-14 | 11:20 AM
  #93  
welfare's Avatar
Senior Member
 
Joined: May 2010
Posts: 535
Likes: 0
From: vancouver, bc
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  
clokker's Avatar
Cake or Death?

iTrader: (2)
 
Joined: Jan 2007
Posts: 10,249
Likes: 63
From: Mile High
Air in the system working it's way to the MC and escaping via the reservoir.
That would explain the time delay.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
astrum
2nd Generation Specific (1986-1992)
24
11-15-17 09:44 AM
Frisky Arab
2nd Generation Specific (1986-1992)
13
08-18-15 06:30 PM
GrossPolluter
2nd Generation Specific (1986-1992)
4
08-16-15 10:50 AM
befarrer
2nd Generation Specific (1986-1992)
4
08-14-15 05:18 PM




All times are GMT -5. The time now is 05:34 PM.