I have a 90 civic std i was replacing the master cylinder in my car and we ran into a couple bumps but finally got it done...too much bleeding for me. Well i drove it around the corner and when i fired the car up it was idleing higher then it ever has(holding at 2100!!) and i was wondering waht was going on but i figured maybe my car had to get hot again because it sat for 2 days, anyways i drove it around the block and brakes worked fine then it started to bogg in between 1000-1500 but it drove fine when it was ideling. we went back to the house to see what was happening and one of my coolant hose's(the one that goes from the radiator to the head) was infalated with air!! I could hear it idleing really hard and i figured it was something to do with the master cylinder and i started to torque it down, forgetting that there was a tourque limit on this bolt, and it snapped in half when i was trying to tourque it on. This sux because now i am going to have to take the hole thing off and i was wondering is there a gasket i might be missing that is making it leak air? we went to the bleeder next to the coolant line and drained all the air out of the line and it was ildeing PERFECT then when it was sitting i guess maybe because i had snapped the stud on the brake booster/ master cylinder and it wasnt all the way sealed so it started bogging from 1000-1500 up and down up and down up and down. now i a going to replace the stud, if I can, and my question is...i bout this part from autozone would they have possibly forgotten the gasket or maybe expected u to buy the kit or something? if so would that be my vacuum problem?? HELP!!

 

there is a gasket between the mc and rrake booster. its a rubber piece like 1.5 inch in diameter. dont know if autozone sell their new mc with a new gasket so check it out ...mmaybe you have 2 gaskets in there or none?

If you broke the stud on the booster...your gonna need to replace the whole booster. good luck man... Hey why dont you upgrade to a bigger booster and master from an crx si? good time now.

 

there's a gasket b/t the MC and booster. sometimes rebuilt ones come with it sometimes it doesn't. they sell them seperately too.

if the booster is leaking, or the seal isnt there, you will have idle problems.
make sure your vaccum line from the booster to intake manifold is hooked up and not leaking. and your check valve is pointing in the right direction.

fyi, for when you buy a new booster, the 90-91 EX one is 9" whereas all other ED ones are 8".

 

Why would he want to "upgrade" to a different booster & master cylinder. If you have stock brakes, keep everything stock. Your gonna risk upsetting your brake balance with lower line pressure (from a larger master cylinder), and haveing rediculously touchy brakes (from a larger brake booster)...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94eg! &raquo;</TD></TR><TR><TD CLASS="quote">Why would he want to "upgrade" to a different booster & master cylinder. If you have stock brakes, keep everything stock. Your gonna risk upsetting your brake balance with lower line pressure (from a larger master cylinder), and haveing rediculously touchy brakes (from a larger brake booster)...</TD></TR></TABLE>

I am going to agree with you on this one....Except for maybe going to just a slightly larger M/C...and leave the booster then upgrade the pads. I guess its all in what he wants. I am sure right now he just wants it to idle like before.