So I'm definitely in worse shape than before the replacement. I went through about 50 ounces of brake fluid bleeding all 4 lines just to be safe. The car now has almost NO braking power. The pedal is extremely mushy and comes back up somewhat slowly when I release it. Could it just be a bad cylinder?

I accidentally let the cylinder go dry when bleeding the first line, but I continued bleeding until the air came out and the pedal got firmer. When the engine is off, the pedal feels firm, but when the engine is on it gets really soft. The order I used was RR, FL, RL, FR.

I'm no mechanic but I have a pretty good understanding of cars. I'm not sure what the problem can be. The only instructions i didn't follow was getting the master cylinder to depress no more than 1/8" during bench bleeding. I really appriciate all the help guys.

 

What order are you bleeding the wheels?

The only other thing I think of is I've seen more than once is the fluid comes out clear then after bleeding some more the last bubble comes out.

 

Sorry I updated the last post with the sequence. It was right rear, left front, left rear, and right front.

 

Was I supposed to adjust the push rod on the brake booster since I went from an oem master cylinder to a Dorman master cylinder?

 

How are you bleeding the brakes; procedure?

Pump, hold, bleed?

good luck

 

Right. Push brake, open bleeder, close before pedal touches the floor, release brake and repeat. I really didn't get many bubbles but I bled a ton of fluid so I know I must of cleared the lines. About one and half 32 oz bottles. Now I'm wondering if the brake booster might be involved.

 

Have you looked carefully for leaks? That's a lot of fluid to bleed.

Something fundamental is wrong; bad MC or leak seem most likely.

Can you pump the brake and hold brake pressure, or does brake pedal go soft?

good luck

 

You DO need to check the length of the pushrod coming out of the master cylinder. There's a special Honda tool to transfer that measurement over to the booster & properly adjust the pushrod through the booster.

When I did it (OEM MC) I checked the length of the pushrods in the MC, against each other and they were identical. So I didn't need to get that tool.

It does kind of seem like your new pushrod is too short, so you press the pedal halfway down before the internal vent closes. But I wouldn't trust that observation without actually measuring the pushrods.

 

if i hold the brake down, it seems to stay in place so the back pressure seems good. i havent really gotten to try it out too much because i have a steep driveway and the car takes several feet to stop even at 5 mph. i checked for leaks and the fluid level doesnt look like its going down so i dont think its that. at this point im thinking i must have gotten a faulty MC. i just dont understand why the pedal is returning so slowly now. was i supposed to do something with the center port on the MC (between the fluid ports)? i'm guessing thats for air.

unfortunately i realized that after the fact. i am going to remove the cylinder and do the adjustment but that shouldnt affect the braking power. it would just cause the pedal to have no affect for the first inch or two. i definitely have a gap because the first 1.5" of play doesnt do anything, but i would think once the rod makes contact with the MC, i should have full braking force.

 

It might be that the vacuum ports in the brake booster (that give "power" to the brakes) aren't properly synchronized with the action of the MC.

I don't have a shop manual here, but it seems to me that you measure the shaft of the MC and transfer that measurement to the shaft going through the booster. That's different from just adjusting the pedal height.