tonight I swapped the booster/MC on my car to a 15/16" off an Integra RS.
everything goes fine with bleeding and install related things but...

I start the car up and HEAR the vacuum leak , it seems the booster/MC dont wanna seal.
on the lower side of the master cylinder where it meets the booster is a very large vaccum leak.

has anyone ever come across this before ?

I used Black Hi-temp RTV for a temporary fix BUT I'm not happy with that as a fix.

there is NO gasket between them , checked the old combo and they were the same way.
I got the two items off two different cars , any thoughts on that having any problems ?
I've changed MCs before and had no problem using the old booster , BUT this was with a MC ....

I'm at a loss , I dont like using RTV as a fix.

any ideas ???

 

anybody ??

 

hi.

I installed a GSR master cylinder and vacuum booster on my hatchie. there is a rubber seal between the master cylinder and the vacuum booster. I left it out and there was a massive vac leak. ssssssssssssssssssss.

took it apart and put in the seal and it was perfect.

good luck
Todd

 

thats what I thought it was , however the rubber seal is in place.