Brake system hissing and Hard pedal

[disco dan]

Hi

I have a modified RRC 94 Soft Dash and each time i push the pedal it hisses which i am used to in my D2 but it won't go away until i release. Also the brake pedal is very hard to push and when at lights it affects the idle. I guessing a bad booster or vacuum leak as you need to have a strong leg to stop. It has also had the ABS removed and non abs fitted

Any help would be great

Thanks Dan

[Blknight.aus]

booster vac leak, if you're lucky its the balance valve which from memory can be changed without splitting the booster.

[disco dan]

booster vac leak, if you're lucky its the balance valve which from memory can be changed without splitting the booster.

Thanks for reply were is this balance valve and what should i be looking for

[1950landy]

Depending what type of booster you have ,If there is a round 10mm pipe between the front & back chamber of the booster with a small joiner hose , these hoses are prone to split .

[Blknight.aus]

Thanks for reply were is this balance valve and what should i be looking for

on the front of the booster where it mounts onto the firewall.
part D, the poppet valve in this picl (http://automotorpad.com/mercedes/206559-mercedes-ml-brake-booster-seal.html)

[aussiebushman]

Don't claim to be any kind of expert, but if it a 95, surely it has ABS? If so, there is a bleed valve on top of the control unit so check the connections for an air leak, especially the copper washer on the side of the pump, top up the fluid and bleed any air out of the system

Don't yell at me if I'm wrong - just trying to help