mike:

Car: 1994 Honda Civic EX Coupe Non-ABS, rear disc brake swap
Component: Brake Proportioning Valve Swap for Rear Disc Brakes


After going to an autocross event recently I noticed that I am probably not getting the most out of my brakes and after talking with another civic owner he recommended I swap out the prop valve to one designed to work in a car with discs in the rear. So I went to the junkyard and got one out of a DA integra as that is what my rear brake setup is from. The 3030(stock civic) and 4040(fromt the integra) have different mounting brackets so I modified the 4040 bracket to fit and mount to the original location. There was more modification to get it mounted but thats not the point of the post.

After bleeding the brakes twice I took it for a ride around the block and had poor braking from any substantial speed and the pedal went all the way to the cabin floor to stop at rolling speed. It is not a problem of bad brake pads or rotors as it worked decent before.


Could I have a bad prop valve. Or could it be that the main brake master is not equipped to deal with this prop valve?

I will bleed the brakes again tomorrow and report back

Kozy.

Sounds like you've got a LOT of air in the system more than anything else.

redlinetuning

Try bleeding the system again. Probably just air still in the system. Start from furthest wheel from the master cylinder. You should check the master cylinder. I upgraded my master cylinder to a 15/16". I have a 98 civic dx with itr brakes. I wanted the 1", but was able to get this 15/16" for dirt cheap. If I ever have to replace it then I'll step it to the 1".

The mc made a huge difference. I also autocross my civic.

mike:

Thanks for the advice. I bled the brakes in this order: rear passenger, rear driver, front passenger, front driver. As I said I bled them twice but as soon as the rain lets up I will bleed them again.

hungrygreen_gsr

As redlinetuning mentioned, you might want to look into a bigger MC. The stock MC and booster were meant to be used on the original smaller front brakes rear drum setup.

mike:

That's what I was thinking as I have almost all of an integra brake setup and only the MC from the civic. I just wanted some feedback on how much of an improvement I would expect given my setup. So if I'm getting an integra MC are there any quality remanufactured or new ones available. I would rather not go with traditional parts stores (Autozone and Advance), as they seem to be of poor quality compared to OEM especially with an item that has moving parts.

*Just to be clear, should I be looking only at non-abs DA integra brake MC's or is there a good deal of crossover for other cars i.e. legend, accord, civic from similar years.

** Should I also look into changing the brake booster?

hungrygreen_gsr

You could always go back to the same DA you grabbed the 4040 from. Put if you want new I would suggest Rock Auto. I've always had good experience with their parts and they have really good prices.

Kozy.

The MC should not be causing the issue you're having.

Give it another bleed, a long gravity bleed would be best. A quick one like you'd do when changing a caliper really isn't going to cut it here, you've replaced something right at the center of the hydraulic line so it's going to take a good while to get all the air out.

If the problem doesn't improve after that, then try a new MC.

hungrygreen_gsr

You can use a ABS MC but you have to modify one of the lines. The fitting size is different. I would link to the thread that would answer all your questions, along with pics, but I'm using the app. Go Team-Integra.net and search for ABS Removal.

mike:

To everyone that did the MC and prop valve swap, how did you do it?

The prop valve requires a bracket to be made to mount to the civic firewall.

The MC does not fit on the civic brake booster as the mounting is flipped. Civic MC mounts passenger side high and driver low and the integra mounts driver high and passenger low.


No part of this is a simple straightforward swap and requires the integra brake booster that has not been mentioned yet in this thread so a fair warning to anyone trying to attempt the 4040 and DA master cylinder swap.






The difference in depth that goes into the booster




So before I go and pull the brake booster out of the DA integra will it even fit on the firewall of an EG civic, please only comment if you have done it successfully.

hungrygreen_gsr

I'm really sorry if I was vague in any way. I have a DC Teg so I just had to swap over parts from an RS Teg and I was good to go. I did mention that you should grab the booster however. I did not know that the MC's mounted differently though. That's my fault for assuming.
For mounting the prop, I would bend or fabricate the bracket. Maybe using some pieces of aluminum bar drilled out for mounting holes.

DJackson1357

For the proportioning valve I just swapped the brackets. It uses a safety torx IIRC, but a pair of vice grips did the trick. It worked fine for 5 years before it started to leak, but not where it bolts together.

A master cylinder from a 91 or so EX bolts right up and is 15/16. You might want to double check the year and exact model for this as it has been 5+ years since I did it. Worked perfect for a 4 wheel disc setup with the Integra front calipers and later front ITR style brakes.

DJackson1357

A few more things after reading this again....

The bleed order is wrong I believe. I thought it was passenger rear, driver front, driver rear and passenger front. Always works for me.

Ive used the 3030 and 4040 valve with a similar setup and never noticed a difference between the two.

The stock EX MC is a bit soft with the rear discs, but works fine in daily driving. The larger MC gives a bit firmer pedal and less travel for equivalent braking.

mike:

Sorry if I came off as hostile at all there, I was a bit heated when I wrote this, more from chasing a large german shepherd away from mauling my cat at the time, childish I know, but this is simply my review and maybe even a guide for people with 94 civic's that want to go rear disc so they have a bit more of an understanding going into it than I did. Hopefully the junkyard is open tomorrow, if not I'm stuck until Monday.

I'm hoping that the DA integra brake booster fits flush in the engine bay with minimal modification or at the worst case I have to return to my stock MC. I'm just surprised I didn't read this anywhere online as I cant imagine I am the first to ask questions or have problems with the whole process.


I will certainly look into other MC's I didn't even think to look at earlier civics but I will find out and report back here what I find elsewhere to save people the trouble.

FrostyEG

iTrader: (1)

There are pages and pages of posts on the rear disk swap. What you want is the EF or EG or DC MC 15/16" or 1". The best fit would be a 90/91 EX MC. Keep the booster and the above MC will bolt right on.
See the sticky at the top of this section here https://honda-tech.com/forums/suspension-brakes-54/brakeexperts-brake-chart-thread-civic-brake-upgrades-ef-eg-ek-integras-3044628/

mike:

I finished the brakes today and I must say I am more than impressed at the car's braking ability and would recommend to anyone with rear discs to upgrade the MC as well as the prop valve and if necessary the brake booster.

The link in post #15 mentions that the EK civics have more direct bolt on MC's to the stock EK BB as well as several options for what fits what and from what car you can find it. A nice read even if you aren't looking to upgrade your brakes.

Just a few tip/tricks if you find yourself going to the junkyard for parts.

*Note the mounting direction of the MC to the BB(brake booster), the two studs from the BB, as for my application, a DA integra RS MC will not bolt or mount to a stock 1994 Civic EX BB no matter how much you want it too.

*When taking the MC out of a junkyard integra/civic cut the hardbrake lines as far away as you can from the MC. I did this and was able to carefuly bend the hardlines back into the MC reservoir to avoid having to bench bleed the MC as well as cut down on spillage.

*When removing the hardlines from the MC or prop valve in your vehicle have some soft rubber hose ready to put over the end of the now open line with the other end of the rubber hose in a container that can catch the dripping fluid. Just push the rubber hose onto the threaded nut, just do it. This saved me hours by not having as much(actually no air) air in the lines when I went to bleed the system.

*There is very little wiggle room underneath the dash and if you are in a junkyard chances are it isnt as clean as your own car, hopefully, so bring a nice water resistant mat to lay on, think yoga mat. Also bring some swivel joint extenstions for 1/4" and 3/8" as you will have trouble removing at least one of the four nuts on the inside of the firewall.

*Be sure to clean the rubber gaskets that are on the BB to MC, do not forget them at the junkyard. I cleaned mine with some engine oil and an old toothbrush, nothing abrasive and nothing that can cut or tear the rubber gaskets. I called the local auto parts stores, Honda and Acura dealerships and these gaskets are not sold so be warned.

My Process:

I changed the prop valve, bleed it, wasn't satisfied, pulled the MC, noticed the integra MC wouldnt fit, pulled and swapped BB, installed integra MC to integra BB and bleed again.

Difficulty: 3/10
Time: By myself with the unexpected setbacks about 8-11 hours

mjch3n

^^great information thank you

hungrygreen_gsr

Glad you got it all worked out mike. Which rubber gaskets, and do you have any pics, are you talking about?

mike:

Thanks guys and if this picture helps here it is, if not I have my old BB and MC in the garage which I can take a picture of.

speedjunkie_g35

Why recover what has been covered in brakeexperts thread??? This is just clutter!! It also shows brake lines have to be rebent to fit any other mc other than a 91 civic 4dr ex.

You have to bleed brakes several more times before it firms up.

mike:

First of all, calm down Sally and secondly I reread brakeexperts thread a second time since it was posted but will now respond with quotes from the article.

In the very first paragraph lies this utmost important statement from brakeexperts "These setups were designed for the EK civic which came with either 9.5" or 10.3" brakes." The firewalls on the EK and EG/EJ are different.

In the "Brake Bias - Proportioning Valve" section he writes "The 99-00 Civic Si comes with the same shaped proportioning valve as any 96-00 Civic, so swapping the proportioning valve is a bolt on job" and that is fine for the EK but clearly as I tried to "bolt it on" to my 1994 civic, it did not work without modification.

"Master Cylinder relative to the Caliper
When you go to bigger caliper than use a larger piston, you are pushing more fluid through the brake lines. Therefore, you should want a larger master cylinder to push this more fluid.
General rule is…with your stock Civic DX, with the stock front calipers, keep your 13/16” MC. Any bigger and your pedal will be too stiff.
With EX/Si calipers, use a 7/8” MC from a 96-00 EX or 99-00 Si because of the more fluid going to a larger piston.
With ITR/Legend/Vigor/Accord V6 or Integra DA or DC calipers, use a 15/16” MC from a 98-01 Integra LS to accommodate for the even more fluid. Any smaller of a MC will cause the pedal swing to be too long.
With NSX or Legend GS calipers that have two pistons, or an aftermarket caliper with multiple pistons, you’ll want a 1” MC because of even more fluid required to push all the pistons. Get the 1” MC from a 98-01 Integra GSR or ITR MC as it bolts onto the EK brake booster.
When changing out a master cylinder, be sure to 'bench bleed' it first. This involves having fluid in the resovoir and pumping it unconnected to allow fluid to fill the internals. If you don't do this, you can still bleed the car, but you may be at it all day, since air pockets may stick in there. Research bench bleeding before you attempt this on your own.
A bigger caliper usually has a bigger bracket, thus holds a bigger surface area pad. This is generally better, and that’s why on a Civic, you swap on an Integra caliper, because the piston is bigger (more fluid, that doesn’t help) but the pad is bigger, and the piston disperses its energy over more area because of a larger contact surface with the shim."



What more can I get from a thread that does not make reference to my specific vehicle, please for the sake of information reread the brakeexperts thread here and report back with anything useful to add to this. Where does he mention that "It also shows brake lines have to be rebent to fit any other mc other than a 91 civic 4dr ex." I DID NOT bend any hardlines for fit.

Brakeexpert's Informative thread based on an Ek
https://honda-tech.com/forums/showthread.php?t=3044628