blaze739

i'm new to the forum but i figured i would ask for help and test your expertise. the master cylinder on my 94 accord was starting to fail (pedal would slowly sink at stop lights) so i replaced it this weekend. now my pedal doesnt sink at stop lights, but i have almost no stopping power. if i slam on the brakes on a hill doing 20mph, it takes about 5 seconds to stop. the pedal is very mushy/soft, and if i push hard enough, it will sink almost to the floor with very little affect on how quickly the car stops. the other issue is that the pedal does not return quickly when i release it. if i let go of the pedal quickly, i will feel the pedal separate from my foot as it slowly makes its way up. anyone have any idea what the problem can be? i'll put the MC installation steps i used below. thanks for your help.

• bench bled the master cylinder until no air came out.
• installed the MC and bled the fittings at MC by pumping the brake and slightly opening each fitting separately
• bled all 4 lines in this order RR, LF, LR, RF (i went through about 40 ounces of fluid to make sure all lines were completely flushed)

i only thing i didnt do was adjust the booster push rod even though i went from an OEM MC to a Dorman MC. but i think that would just cause the first inch or so of the pedal to have no effect (the pedal does feel like it does nothing at first). i dont think that would affect stopping power once the rod makes contact though. Lastly, when bench bleeding the MC, the instructions said repeat until there is no air and the piston will not travel more than 1/8". i bled for about 20 minutes and the piston never got firmer. it continued to go in the full length even though there was no air coming out.

tron_

You probably have air in the lines from not adjusting the booster rod. Adjust the rod length and rebleed. That should fix your problem.

blaze739

i am pretty sure that the booster rod makes physical contact with the master cylinder in open air. i do not think it is a sealed system so there should be no way to get air trapped between the two. correct me if im wrong but that was my understanding

eriki

iTrader: (2)

i also dont see how adjusting the booster rod would cause air to get in the system. But OP sounds like you do have air in your system.

tron_

I just read you bench bled the master. There's a possibility you did not completely bleed it or air somehow found its way back into the system and an incorrectly adjusted rod is keeping the air trapped. It happened to me when I switched to a 1" master.

blaze739

i see what youre saying. it doesnt seem possible that i have air in my system considering how long and how much i bled everything, but the symptoms do sound like air. ill try rebleeding again and if that doesnt work, i'm going to exchange the cylinder. i am using a Dorman but maybe i'll go to a Wagner. I think that is considered a better brand.