what is that?

[Cautrell05]

93EX, what is the block on the rear lines under the master cylinder? On the non abs models that's where the prop valve is. With the ABS models there is just two lines for the rear brakes. Does it limit pressure to the rear wheels?

[Cautrell05]

Anybody?

[AAPOQ]

Lets see some pics

[Jarrett]

The back side of the proportioning valve routes brake fluid to the rear wheels. That's what this block does. Can you not tell by the two lines going from the backside of it toward the rear of the car?

[cp[mike]]

as far as I'm aware, it is nothing more than two pass-through line couplers mounted together on a bracket.

[Cautrell05]

The back side of the proportioning valve routes brake fluid to the rear wheels. That's what this block does. Can you not tell by the two lines going from the backside of it toward the rear of the car?

I am aware they go to the rear brakes. That was stated in the OP

as far as I'm aware, it is nothing more than two pass-through line couplers mounted together on a bracket.

Thats what i assumed also. The abs valve was replaced with an adjustable prop valve. One line from the M/C to the front lines and one to the rear lines. Problem is i can not get squat for pressure to the rear wheels. Enough to lock them when on the hoist but on the street they dont do squat. With it set to max rear brake I can run it hard enough that the front wheels are hot to the touch and the brakes stink but i can reach through the wheel and touch the rear rotor and its hardly warm. If i turn the knob the other way the fronts lock up sooner Pedal is solid, no air. Master ASE tech for 20 years, raced dirt track for 15 so i under stand the system. However i have very little experience with hondas. Gut feeling says that valve under the master is blocking pressure to the rears but then again i thought the bias was built into the ABS valve to.

[Cautrell05]

Extra info, the brake bias problem was there before I added the adjustable prop valve. when the ABS was working it didnt stop worth a crap. No brake authority. after the ABS quit it became very aparent it was stopping with only the front brakes.

[sonikaccord]

The brakes are naturally very front biased on hondas. If you still have your abs things installed, then that max pressure you can get is the one that the built in prop valve in the modulator will allow.

[Cautrell05]

The ABS modulator is gone. the prop valve is bolted down where the modulator used to be.

[Raf99]

I had this problem and it turned out to be the calipers in the rear were orginal and worthless.

But If you cannot turn the rear wheels with the brakes on then its good to go. Usually works out where 60-70% is applied to the front, and respectively 30-40% at the rear as you know. Don't expect the rears to get hot and be exactly the same as the front.

[Cautrell05]

I wish it was 70/30. if I had to put a number on it it would be 95/5 right now.

[Raf99]

I wish it was 70/30. if I had to put a number on it it would be 95/5 right now.

haha. well assuming you can't move your wheel with the brakes on means they are working. There could be a block in the prop valve but I doulbt that would make a difference here. Are you sure your calipers in the rear are working?

[cp[mike]]

yeah, how are the calipers, and the slider pins?

[Cautrell05]

I will pull the back wheels next week some night after work and see what they look like. I know the right rear caliper was replaced not that long ago.

does anybody know for certain if the valve under the master cylinders is just a pass through or if it actually regulate pressure?

[cp[mike]]

i read through every page of the Helms manual and it doesnt even mention that unit, it keeps mentioning how the ABS modulator/solenoids themselves are valved to match front/rear balance. It would probably be easy to swap in a couple direct 10mm line couplers in place to eliminate the thing in question from the equation. Unfortunately I can't give you a definite answer, but I am curious as well, if anybody else knows for sure.