so i threw out the stock drum set up in the rear on my 90 crx dx, and threw in crx sir rear disc conversion i got the lines and everything hooked up..

i first performed a gravity bleed on the entire vehicle starting with the rear and finishing up wit the front, then i had someone help me by stepping on the pedal a couple times to build up pressure and i bled the brake system starting with the rear and finishing in the front....

now here my problem when the vehicle is off the brake pedal is nice and firm and with the vehicle on pedal goes all the way to the floor and is real soft, took the car for a spin and it does come to stop BUT VERY GRADUALLY doesnt feel right.. OBVIOUSLY something isnt right


i checked out some specs on the parts and so far couldnt find anything on the proportioning valve but did find out the master cylinder is different in bore size, BASE= 3/16 bore and HF-SI= 7/8 bore


now can my issue be both the master cylinder and the proportioning valve need to be changed or just one or the other.....

 

start with a 40/40 prop valve

 

If the OP has stock brakes up front, he would need a 3540 prop valve. If the OP also upgraded to EX or DA brakes up front he would need a 4040.

 

Your Master Cylinder might have a leak. There is a plunger inside and the hydraulic fluid is bypassing the internal seal. Fluid MAY come out and get into the mounting surface on the Brake Booster and then leak down the Booster, but it's kind of rare to see that happen. Usually it's all internal and your bake pedal is the only indicator of a problem. In the normal case, the fluid level remains good. In the rare case that it leaks out over the booster your fluid level will drop.

Other problems may be a leaky cylinder at the wheels. You should notice fluid loss over time. This problem happens a lot on the rear drum brakes. You should probably check this before attempting to change out the Master Cylinder. Take the wheels off and inspect for signs of leakage (for the rears you will have to remove the drum to see the cylinder so block the front wheels well and don't set your parking brake when you get the rear up). If the leak has been there for a while, then dust will have collected on it and the wet area will look muddy.

 

sorry brain fart

 

4drEF is correct, I think his suggestion fixed my issue as well, my MC took a crap. Slow sinking pedal when car was on only. Replace MC "bench bleed also"

Im also using a 40/40 from a Teg also, might as well switch to that while you have the fluid some what drained

 

OK so I'm looking at the prop valve then more than master cylinder being the issue????
Does anyone.have a prop valve or know where I might be able to buy.one.new???? And I have been doing some research on my vehicle being that I didn't now swap the front steering.knuckles to fit a b series motor in it, but the vehicle did come with am ls but I swapped it out for an obd0 b16 and I do have the integra brake setup so I'm going to need that 40/40 prop valve then.....

 

Just to clear it up my pedal isn't slowly sinking but it only gets hard half way and I do not have rear drums I converted to disc so I don't have to check for leaking wheel cylinders, I double check the pistons and slider and replaced everything that looked might give me Amanda issue and the yea this is where Im at after doing everything I'm proly just going to buy both the prop valve and MC

 

So your brakes work, but only after you press about half way down?
More than likely you have air in the lines from not bleeding correctly.

Your original post sounded like it was gradually sinking to the floor.

 

After re-reading your first post, I realized you've bled your brakes incorrectly. You're supposed to go:

1. Passenger rear
2. Driver front
3. Driver rear
4. Passenger front

Our brakes are a dual system and work in conjunction diagonally, 1+2 and 3+4. This is so if one brake system goes out, the other can still stop the car with one front and one rear on opposite sides.

 

With Integra brakes in the front and rear disc in the back, you do need a 4040 proportioning valve and an EX brake master cylinder.

 

OK now this I did not know and was very useful info I will perform this tomorrow when I have a chance and as well as sourcing a 40/40 prop valve.... in your guys opinion would the si MC be Amy better than the base MC in performance range like

Ex. Bigger bore= more fluid volume pressure= stiffer pedal/brake application??????

 

I have never bled brakes like this. Always go from farthest from mastercylinder. Right Rear, Left Rear, Right front and Left front.
When you bleed the system have someone pump 3-5 times and hold then release the valve per corner. Do this several times until a steady clean fluid comes out through each corner.

 

That's the order Honda's service manual says to do it.

 

Since it's two hydraulic circuits you are essentially doing the same thing.
The problem is that you could potentially get a bubble because you are only bleeding half the circuit and then pumping the brakes when you have switched to do half of the other circuit.
It probably works ok for a flush, but on a dry system it will probably give problems.

 

i had the same problem with my 91 4 door, i have integra rear brakes with stock brakes in the front.
The brake pedal went about half of the way down before the brakes would actually engage. I just upgraded my MC to and ex MC and the brakes felt great, it was almost instantaneous after pressing the pedal, it would start braking.