Okay, this is somewhat lengthy, but I am going to be as descriptive and precise as possible to help in your thinking of what my problem can be.

Here's my deal... I pulled my ABS out. Now the brakes completely lock up on me after driving for about 5-10 minutes. I mean COMPLETE lock. Like I can't accelerate at all. Like someone is pulling an e-brake on all 4 wheels at the same time. They STAY locked for about an hour or two afterwards, until the brakes cool COMPLETELY.

Here is my setup...
Stock ITR brake booster
Integra RS master cylinder(purchased new, OEM)
Used Integra RS proportioning valve and hard lines
Goodridge stainless brake hoses
Stock ITR pads, calipers, rotors
Ford DOT4 Performance Brake Fluid, complete flush

I did all the brake modifications at once, and everything was swell, until I got about 5 miles on my way home and the car gradually decelerated on its own. I was stranded and needed to tow it. By the way, we had a FUN TIME getting the car on the flat bed, too. Remember, brakes were 100% lock.

I towed it to my friend's shop and left it for the night. Came back next morning, and system was fine. Drove up his street two times and it was all good. I thought maybe the previous day was a freak occurence. Odd, but nonetheless, a freak occurence. I was wrong. I went to the store to get some stuff, and it happened again on the way there. It happened on a slight incline, so I didn't use the e-brake. The car was not moving at all. After waiting for a tow for about 45 minutes, the car started rolling.
I was like WTF! So we towed it back to the shop again, and then I called my friend, who just so happens to be the master technician at the Honda dealer. He suggested I check the brake booster to master cylinder pushrod clearance. I had never done such a procedure before, so he came by and checked it. It was out of spec by approx. half a turn. SO we both assumed this was my problem. Wrong again. Full lock on my way back to Acura. ****!! I called him, stranded from the side of the road. He told me over the phone to pull the main vacuum off the manifold. I did, and nothing happened. He said something along the lines of, "if the booster was fucked, the brakes would have let up when I did this". SO he had me undo the two 10mm feed lines coming out of the master cylinder. Brakes release immediately. He said if the fluid rushed out the holes instantaneously, the master cylinder was the culprit. No such luck. They just drizzled, which I guess is normal.

Next step was to replace the proportioning valve, since it was the only "junkyard" component. So I replaced that today to no avail. Same problem. Next step is, tomorrow we are bleeding the brakes and flushing the system with OEM Honda DOT3. He said maybe the Ford fluid, which he doesn't know much about.. may have a lower or higher expansion rate than the Honda fluid, and it might be ******* with the master cylinder ot flow through the lines.

SOMEONE PLEASE HELP! I am running out of options. Also, we concluded it can't be a caliper. I mean, what are the chances of all 4 calipers taking a **** at the same time? It has to be something relevant to the ENTIRE brake system. Booster, master cylinder, lines, prop valve.
Prop valve... check. New item.
Master cylinder... check. New item.
Lines... check. Hoses are new Goodridge, hard lines were junkyard but thoroughly cleaned upon installation. No problems here.
Booster... not quite sure. It functioned fine before I removed the ABS.

Any help is kindly appreciated.

-Mike K(stranded with a shitty brake system on a sweet *** car)

 

Despite what you described as drizzle - I suspect that upon release the brake circuits are not open to the reservior. Then as the fluid heats and expands: line pressure. I'd be looking at the MC and Booster. Brake systems are to dumb to fool humans for long.

Scott

 

I'm using the ford MotorCraft high performance fluid with no problems, D has used it as well and didn't have any trouble. That's a dilly of a pickle you've got there! Does the pedal do anything weird when you're experiencing the problem?

 

Try this. Start car. Pump brakes(15 times). Does it lock up now, are you able to move? If not there is a bad check valve(or whatever) that isnt letting the pressure bleed back into the M/C.

I think that its not related to the time or temp, just that you have used to brakes a few times and they never bled back.

Just my .02

Good Luck.

 

The pedal doesn't do anything strange, even upon lockup. It feels like a nice, stiff pedal. They way it SHOULD feel.

I was looking in the parts catalog here at work, and it showed that my booster is a 8"+9" booster, while the non-ABS Integra RS is a 7"+8". Does this mean anything?
I'll try flushing out with OEM fluid and replacing the check valve today.

Thanks.