I just installed all around gsr brakes w/ a type r bb/mc in my 96 civic. I bled everything, but the pedal is still very spongy. The wheel can still move the first time I step on the brake, but if I pump it a few times, it'll brake like normal.

I'm thinking that the pressure in the brake lines is low so I was thinking about switching out the proportioning valve. My car is non-abs so I was wondering exactly what proportioning valve should I get? Also, if anyone has any insight on any other potential reasons why I'm experiencing this, please let me know. Thanks in advance.

 

You'd want the 99-00 Si prop valve if I recall correctly. Does your brake pedal sink slowly to the floor if you apply steady pressure? When I put in my (used) 1" GSR MC/booster last year, the pedal would start getting spongy and slowly sink to the floor when heatsoaked. Replaced it with a reman MC and haven't had a problem with it since. Also, are you sure you're bleeding it properly? In any case, you should get the appropriate proportioning valve to maintain the proper brake balance anyway, but the problem you're describing sounds more like an MC issue or air still in the system.

 

thanks for the input. the brake pedal doesn't sink in slowly...when i step on it, theres a little bit of pressure, but it just goes all the way to the floor. it stiffens up and brakes if i pump it. i just tried this with the car on and it doesnt stiffen up anymore, it just stays soft.

i'll try to find another mc to work with. meanwhile, any other advice?

 

prop valve and mc are not your problem. I assume your brakes worked properly before the swap, so that means that your mc + booster are fine.

Your spongy pedal indicates that you've got a ton of air in the system. I would expect that you would have to go through a full litre of brake fluid to properly bled it.

You introduced a lot of air into the system with the line and caliper swap.

I'd suggest you gravity bleed and get a mityvac.

As for the correct prop valve. If you have a cx/hx/dx/vx/si then you already have the correct prop valve. You only need to swap if you have an ex.

 

the prop valve in your 96 civic is not the correct prop valve for gsr rear disc brakes. also, the 99-00 si prop valve is different than the prop valves on any other model.

the 20/40 or 30/40 prop valve in your car now will not give you all of the braking power that could be had. whats happening is that your rear calipers are not getting the proper hydrolic pressure with a 20/40.

yeah, it will still work, but you should replace it with the prop valve that comes with the gsr rear disc brakes, which is a 40/40.

 

so i'm guessing the one i have now is sufficient, but it would be better if i change it to a gsr one? is there a specific year and/or model of gsr i should take it from?

i'll try to bleed the brakes some more, but when i bled it last time, no bubbles were coming out anymore, just clear liquid.

but it sounds like u guys dont think its to do with the calipers? can i rule that out? thanks for all the insight!

 

does the pedal go all the way to the floor if you just step on it once and hold??

 

After doing some digging around, I found that all of the 96-00 CX, DX, Si Civic coupe/hatch prop valves are the same. The EX sedans have ABS, so their prop valve is different(and from what I understand the ABS modulator controls most of the proportioning anyway), and the EX coupes have their own part number. For some reason the LX and DX sedan prop valve is different from the rest of the models as well.

So, what I came up with was:

CX, DX(coupe/hatch), Si
46210-S04-902 VALVE ASSY., PROPORTIONING

LX, DX sedan
46210-S04-912 VALVE ASSY., PROPORTIONING

EX coupe
46210-S04-962 VALVE ASSY., PROPORTIONING

EX sedan
46210-S04-852 VALVE ASSY., PROPORTIONING

You can doublecheck the part numbers at http://hondapartsunlimited.com if you like.

 

yea, the first step on the pedal, theres a little resistance, but it goes all the way down. while holding it, the rotors can rotated. even after a few pumps, the pedal still goes all the way down, but it'll grip the rotors and they can't be budged (how it should be). what do you think?

and thanks for the info inspyral. my understanding, was that since i upgraded to all around disc brakes, i should replace my prop valve to one that came from another car that had all around disc brakes (integra or si). but since my civic (dx hatch) doesnt have abs, i have to find another prop valve from a car that both has all around disc brakes, and non-abs. do si's have abs? i've heard some integras don't have abs, do you know which ones?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wendong &raquo;</TD></TR><TR><TD CLASS="quote">
and thanks for the info inspyral. my understanding, was that since i upgraded to all around disc brakes, i should replace my prop valve to one that came from another car that had all around disc brakes (integra or si). but since my civic (dx hatch) doesnt have abs, i have to find another prop valve from a car that both has all around disc brakes, and non-abs. do si's have abs? i've heard some integras don't have abs, do you know which ones?</TD></TR></TABLE>

The 99-00 Si had 4-wheel discs but did not have ABS, and your DX prop valve is the exact same part number as the Si one, so I would just leave it. In fact, if since you're running GSR brakes all around, you essentially have the exact same brake setup(size-wise) as the Si - 10.3" discs up front and 9.whatever" discs in the rear. Actually, I'm not sure what size MC the Si came with, so your 1" ITR MC might actually be larger than the Si's. As for the Integras, typically the lower trim models(RS, LS) will not have ABS.

 

i had the same problem. it was a bad master cylinder. if the pedal goes all the way to the floor with no resistance, it is most likely your m/c.

as for the prop valve answer that i posted...96-00 civics may be different than 92-95 civics regarding rear disc brake swaps. it was my bad to assume they were the same deal. on 92-00, i know for a fact that the prop valves are different and must be swapped to the prop valve according to the brakes, not the car.

 

prop valve from a 98+ accord with out abs will work and bolts right up same style and mounting points as your stock one but porportioned for 4 discs