rubber seal between brake booster and firewall..

**vrmmmpshhh** · 19-10-2013 11:34 PM

hi guys just put a 1inch prelude brake booster in the ek1 to finish off the brake upgrade and heard it hissing when i went for a drive and turned it off. does the rubber seal between the booster and firewall actually seal up anything? i ask because i installed it with 2 rubber seals as i forgot to check if the booster had a seal or not. is there anywhere else it could leak from. ive checked the vacuum line already.

**dorikin** · 20-10-2013 12:44 AM

Test it

**Baby Face** · 20-10-2013 03:07 AM

sounds like a punctured booster.

as mentioned before remove the vacuum hose from the booster and plug it, either with a plug or get a friend whos isnt chicken to thumb over it, remove it closest to the booster (at the black nipple). if the hiss is gone then the leak is in the booster, this happened to me when i did a brake upgrade on my EG from a ABS DC2 and the booster had a slight hiss that i could notice when the engine turned off as it hissed for about 10secs or so.

**grifty** · 20-10-2013 08:41 AM

It could be the seal at the back of the master cylinder.

**vrmmmpshhh** · 20-10-2013 08:59 AM

i think its the booster. i did the tests and with the 1st leak test the pedal rises and i can hear a hissing noise.

**bennjamin** · 20-10-2013 09:21 AM

Did u install the check valve the right way ?

It's the internal or visible grey diaphragm that sits on the booster to inlet manifold line

**vrmmmpshhh** · 20-10-2013 01:30 PM

Seems like the ek1 doesnt have a visible check valve like other Hondas. I never took the hose off the manifold anyway. I removed the BMC and the O ring gasket behind it is torn around the inside diameter. I may have slid the BMC at an angle and pinched it a bit as the setup was in a friends eg not that long ago and working fine. Apart from the slight hissing the brakes are awesome now with the poormans type r upgrade. Will drop by Honda and get a replacement tomorrow. Thanks for the help guys, much appreciated.