2000 civic ex. front caliper was siezing. Replaced caliper 2 weeks ago and siezing again. What I found: so far when I released the bleeder on the left front caliper it released perfect. So I decided to pull the hose off to see if it was obstructed....its not. Put it back on and bled the right front no problem.
Problem is....Im unable to bleed the left front caliper. very little fluid coming out the bleeder screw. This car has abs brakes. disconnected the abs and same problem...I can bleed the right front, but not the left front?????pedal just wont push anything through the left caliper line. Now traced the left front line and it goes into the abs block then out of there I dont know where it goes? I do see a proportioning valve on the firewall with 4 lines coming out of it. ANY IDEAS where my problem lies? Thanks...Im doing this now, so any quick response appreciated.

 

Have you tried completely removing the bleeder screw from the front left caliper? Perhaps the obstruction is directly behind the bleeder screw itself.

Or are you saying that, when you disconnect the brake hose from the left caliper
and then press the brake pedal, no fluid flows from the end of the hose? If so, disconnect the respective bake line from the ABS modulator unit to test fluid flow out of the modulator unit when you press the pedal. By the way, is the dash ABS indicator light ON?

 

yeh ron its a strange issue. I can bleed the right front wheel no problem, but the left front nothing comes out at all. Maybe this is what caused the original caliper on the driver side front to sieze the first time. I installed 2 new calipers a few weeks ago...and that same front left one was locked up tight again. As soon as I removed or cracked the bleeder on it, it returned to being free. So I tried to rebleed both fronts again. The right bled fine. The left, nothing a small squirt at first...then nothing. So my first impression was maybe the rubber line was plugged or no good. Pulled it off at the steel line and its not plugged at all..could blow through it and it looks perfect. The steel line then goes across the firewall directly to an aluminum block with what I think is the abs pump. Looks like Im not getting fluid pressure coming to the line out of that aluminum block to supply fluid to the caliper in question. Im wondering if this may have contributed to the first caliper problem. So the line from the Aluminum block/pump ABS is free and not obstructed. I done some reading that says you need a special tool DBR11 to cycle valves to bleed the abs????? Just seems strange, and Im looking at a way to get the fluid flowing to that left front caliper. Now whether or not the master cyl was run low prior to me owning the car...and air got into the abs unit and thats causing me the problem I dont know???? I need someone who really knows this abs system to give me some advice as to what I should proceed to do from here. How would I get the fluid going to the left front caliper? If I had a schematic of the system or something I could trace the fluid route and see where the problem lies. I have not touched the rear brakes to see if I get fluid out of them...but that might be something I should look at...maybe. thanks for assisting!!! Bleeder screw right out, line off and no fluid. ABS light comes on when key is turned on and goes out normally when car is started.

 

Are you saying that when you disconnect the front left brake line from the ABS modulator unit and press the brake pedal to bleed the system, no brake fluid squirts from the hole in the ABS modulator unit? If so, I think the problem lies with the ABS unit itself. You might try removing the ABS unit to check whether a foreign object is occluding the channel leading to the bad caliper.

Despite the ABS light not staying ON, try to retrieve a trouble code from the ABS system. This is done by placing a jumper wire into service connector (same one used to retrieve CEL trouble codes; see link in my signature). If a code is stored, the ABS light will blink a code when the ignition key is turned to ON(II). For more details, download the 96-00 Civic manual at the link in my signature. Go to the Brakes chapter, which covers both conventional and ABS brakes.

By the way, the brake bleeding procedure for conventional and ABS brakes is identical for Civics.

 

that modulator looks tough to take out just to check it. Is there not shuttle valves inside? that are activated by the abs control unit? Could be a stuck valve? inside the modulator? Thats why i asked how it works..Also....should I get oil out both lines on the master cyl if I crack them? I cracked the front one with pedal depressed and got oil....but not much on the other one???maybe that rear line on the master cyl supplys the modulator and thats why Im not getting oil out of it??? If I have to take modulator out, I want to be sure, thats where the problem lies. I want to see what supplys the modulator the oil for that left front caliper...is it the rear line off the master cyl or the front line? lots of questions I know....pita thats for sure. Im looking for the logical simple approach first...then follow it up from there

 

That's what I was originally thinking.

I think you found the problem -- the master cylinder. The front line appears to serve the right side wheels and the rear line serves the left wheels via the modulator (see diagram below -- download the manual!). It seems that fluid should flow from both master cylinder outlets. This predicts that you would also be unable to bleed the left rear caliper/wheel cylinder.

See my response above.

 

I think we are on to it ron....Im gonna run a test in the morning. Im gonna switch the lines on the master cylinder (Reverse them) just to confirm it. That way if I get fluid out the one Im not getting any now...its a done deal the MASTER is toast. Because right now the master seems to supply the right ok...and thats off the master cyls front port. So what I,ll try is hooking the rear line onto the front port and see if I get fluid on the left side....If I do...then theres the problem. Hey Ron...appreciate your quick response and help. I did dl the manual thanks. I,ll let you know how it goes. Thanks so much...two heads are better than one!!!

 

Well Ron, good news and more bad news....the good news is that indeed it was the master cylinder that was the problem. I now get the fluid flow I was missing. The other problem now is that the brake proportioning valve that bolts onto the firewall to feed the two rear drum brakes is no good...its plugged on one side and not allowing fluid the the right rear drum. I took it off...tried to clean it with everything imagineable with no luck. I do know for sure its not working...fluid on the bottom both side..but only out on the one side at the top. Tried to blow it out...spray it and tap it....no luck. Called honda and was told a new one is $169.00 for a simple little valve. So Im looking for a used one if I can find one. Its a 2000 EX with abs if you know of where I can find one...give me a shout. Other than that...thanks for helping me solve the problem!!! One more to tackle and Im done!!!

 

That's good progress. I'd try to get the valve at a local or internet salvage yard. Otherwise, you can purchase a new one from Majestic Honda for about $83 + shipping:

http://www.hondaautomotiveparts.com/

 

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