Mrspencer

Can someone guide me the thread , or inform me on how to remove my brake booster on my 85S3,already have the booster disconnected, master removed What else comes off.
she sure is in there tight..

The Forgotten On

Just wiggle the b*stard until it comes out. That's what I had to do to get it out of my 81 which has even more annoying brake parts in the way.

Also, make sure the intake is mostly off. It can block it from coming out.

hacker-pschorr

The WSM shows how to remove the booster. The rod must be pushed and held all the way in or removing the booster will be increasingly difficult, if not impossible.

I followed the WSM using a plate & hose clamp in my 80. Struggling to remove the booster I checked again, sure enough the rod has pushed out about 1/4", that was enough to prevent everything from clearing. After pushing it back in that 1/4", securing with a second hose clamp it popped right out.

This was with the intake and everything else (except the master) still installed.

Same for installation.



Photo from the WSM

Daniel5691

https://rennlist.com/forums/928-foru...e-booster.html

https://rennlist.com/forums/928-foru...e-booster.html

https://rennlist.com/forums/928-foru...e-booster.html

Mrspencer

Thanks to all got her out and installed in an hour,after all that work I now need to replace my booster check valve.once again I thank you all, my pedal still feels firm, new master new booster rebut, pedal still not enough bite.

FredR

Have you checked the venturi fitting and the hose to the booster to make sure they are not leaking?

[I presume your model year has these just like the later models.]

drscottsmith

Following closely as I am having the same issues. I have pulled my check valve and it seems to be holding just fine, so I am thinking I have an issue with the booster. MC is new - have vacuum in system for first second or two of pedal travel and then I lose it and the pedal goes very stiff.

-scott

hacker-pschorr

When I replaced mine on the 80 I noticed two things:

1. The seal between the booster & MC was missing (not kidding) - so that might have been the problem
2. The seal on the passenger side, under the accordion boot appeared to be bad. When I pushed in the rod it didn't compress with vacuum like the new one did.

I put some of Stans favorite PC-111 between the MC and booster & closely inspected the two surfaces to make sure there were no burrs or other abnormalities.

I had slight power boost upon first try, then nothing in my 80. It's fixed now with the donor booster.