shunpike

will the del sol e brake cable fit or do i need crx cables?

1991si

Question: So I just bought a 1991 Civic Si and it has rear disc breaks. Did some of them come with disc breaks or you think someone did the swap? Thanks guys!

Tyson

civic si's did not come with rear discs. nor bigger front calipers, like the CRX si.

please read the faq's.

d16y8iceberg

Did you use DA rear brake setup or an EM1 setup?

sedrohatchstyle

I THINK the 91 SI hatches did come with a rear disc brake..... i think

for 88 to 91.... use DA non abs complete rear trailing arms... or a CRX rear trailing set with discs...
you'll need the complete trailing arms. ebrake cable.. 40/40 valve... and if you can find it... NOT needed... the 15/16 master cylinder...

Please make sure to read the previous comments how all of this has been covered...

I THINK THE EM1 setup would be good for a DC integra... or a EG... but then yo uhave to think about not mixing ABS with non ABS. Just remember that.

Deetz

The only EF chassis on North America to come stock with rear disk was the 90-91 crx Si

sedrohatchstyle

ok thank you for clearing that up.

esolano

Great info guys!!!

Last night, with the help of a friend, I swapped out the drum rears of my 88 ED Civic Hatch to the discs assembly from the EF9 rears. Bolts on perfectly, no issues with fitting everything in.

Unfortunately now the brakes feels soft. I have read the whole thread but don't fully understand the concept of Master Cylinders and Break Boosters etc. and would like some guidance as to what I need to do next to fix this.

So far my understanding is this:
1. I need to do a brake bleed.
2. I need a 4040 prop valve.
3. I need to replace master cylinder.
4. Brake booster? what are they and do I need them?

Could someone please confirm or give some guidance. Thanks.

sedrohatchstyle

You don't need the master cylinder, and you don't need a different booster...
all you need is.
Rear trailing arms... complete,
ebrake cable from the donor car
and the 40/40 valve...

make sure you bleed the brakes of course...
When I did mine, it took a full jug of bleeding to get the correct pedal pressure.
Make sure you bleed them in order, via the repair manual i think its passenger rear, driver rear, pass front and driver front. in that order

Good luck, sounds like you have all you need right now, but BLEED them well :D

esolano

Thanks man! I had the complete assembly that came with the trailing arms, LCA and ebrake cables already. All fitted nicely
So I guess I just need the 4040valve and do the bleed. Appreciate your help

sedrohatchstyle

no problem man, Yea without the 40/40 it wont have the right pressure to the rear brakes. Definitly needed!

If you want super brakes, you can get the 15/16 master cylinder out of the EG civic or the DA integra. Im not sure what the booster help would be, but if you get the 15/16 MC you might as well grab the booster....

BLEED BLEED BLEED.... mine was a pain. Like I said before, good luck D

esolano

Hey man, would I need to modify the bracket when fitting in a 4040 from a DA integra?

sedrohatchstyle

I just bent mine out a bit... I had problems with my flare wrench not gripping right. should mount just fine. just make sure to hook up the rear to the rear and the front to the front :D
Same layout as stock line wise

949

questions:
what happens if i keep the stock mc on the 91 civic si with doing the bigger brake and rear disc conversion?

what exactly is the difference between the 4040 prop and the 3030 prop?
what is the bias for the front and the rear between the two?

Riceburner247

iTrader: (1)

If you're going to be bleeding your brakes anyways, look into replacing your Master Cylinder with the 90-91 Civic 4dr EX unit. Bolts right up and is 15/16" instead of the stock 13/16". Very easy upgrade that will improve brake pressure.

sedrohatchstyle

Yep just make sure its the same bolt pattern, I remember now its the EX 4door now that you say it :D
I think, i don't remember right but the stock is 30/50? or visa versa, I just know you want the 40/40 for equal pressure.

GeoMetry

I am adding a 4040 valve to my junkyard shopping list. I have two questions; Where is it located on the donor car? Is there anyway I can test it in the yard to insure I get one that works?

Here is the interchange info for that part:

Acura Integra 4AT LS 1990, 1991, 1992, 1993
Acura Integra 4AT LSSP (SPECIAL) 1993
Acura Integra 4AT RS 1990, 1991, 1992, 1993
Acura Integra 5MT LS 1990, 1991, 1992, 1993
Acura Integra 5MT LSSP (SPECIAL) 1991, 1993
Acura Integra 5MT RS 1990, 1991, 1992, 1993

sedrohatchstyle

ummm... as far as I know they all should work. :D I wouldn't think they'd go bad unless the threds are stripped or it somehow got smashed and cracked...
any prop valve that says 40/40 on it shall work.
It is on the passenger side near the firewall... with brake lines connected to it.

949

will the acura NSX mc bolt up?

because its a 1 inch.
or maybe ill need the booster too, so it will then bolt up.

if not the nsx, which other one is 1inch and will bolt up?

sedrohatchstyle

doubt it. There is a integra 1 inch one... I think its a DC. Do some research man. You can find all this junk on the net

Also you find a NSX at a junk yard, you let meknow

949

im not getting anything from the jy. its going to be from kragen. im assuming that the jy parts will only last a little bit longer before they go out. plus the parts at kragen isn't that much more for me. the extra benefit for them to work a few years more is worth the extra few bucks and less effort of needing to redo it again.

i saw the nsx bolt pattern. if its just the mc that's different then i can get the booster too but im not sure if the booster will fit into the fire wall directly. i only chose the nsx because it seems to have similar hose location. so i wouldnt need to relocated my hoses and its a 1inch mc.

what year is the DC integra?

im mainly looking for 1inch.

i also heard about something tricky with ABS mc's. im not too clear on that.

GeoMetry

I looked into getting the valve from Advance auto parts but all the reviews said that "The exact fit" part didn't fit at all. It was apparently a generic adjustable valve of some sort.

Tyson

the brake pedal will have an unsafe amount of travel and may not achieve full brake pressure. its simple hydraulic math.

the difference in the prop valves is unknown. no ones cracked the code on prop valve designations. the very fact that both a 4040 and 3030 exist means its not a ratio. compounding the confusion is that the 3030 came on a DX sedan with regular sized front calipers and drums, and the EX sedan came with a larger caliper, same size as the integra and still had rear drums, yet has a 3540 prop valve. theres no apparent rhyme or reason.

the only advice that can be given when modifying your braking system is to transfer all the parts e.g., MC, front and rear brake and prop valve to match the same system that some honda engineer already figured out as safe.

to repeat, 1725, 3030, 4040, 3540 are not ratios. anyone who writes 40/40 or whatever, is just an idiot and has no idea what theyre talking about. or they are some ricer with a VTECH sticker on their windshield.

949

what is the safe amount of travel that we should be having. as after my caliper swap i have about a 25% travel for it to engage.

sedrohatchstyle

Here comes the ney sayers. Lots of them on this forum.
Show me the differance in the brake pedal travel amount.

You can use your stock MC and booster with your new crx or DA integra rear trailing disc brakes.
Yes a 15/16 MC would be " more " brake pressure resulting in quicker " lock ups "
but my stock dx MC on my Si conversion civic hatch is more than enough pressure with CRX trailing arms and " 4040 " valve.
I can yes, stop on dimes. Plenty of pressure and travel length.

As far as boosters go, yea if they have the wrong pattern get the matching booster...
I have actually flipped my brake booster to finish off the wire tuck. Insted of being top driver corner is in passenger bottom corner. ( the vacuum tube )

Final word of advice man, Any DC integra NON ABS 1" MC and booster will work.
Took me another whole 5 seconds to search it online, I know i've found it before because I once was going to do it myself.

Best of luck. Definitly good to learn.