Posted by Gordon on Thursday, August 08, 2002 at 4:21AM :
In Reply to: Vacuum Brake Booster on 1-1/2 ton truck posted by Rawge on Thursday, August 08, 2002 at 0:23AM :
In general terms, as I have no experience with that particular unit....
1. It should run forever as long as you keep your master cylinder fluid level up - it has probably run like this for years.
2. If you want to stop it smoking there should be a drain where you can drain out the brake fluid that has leaked past the hydraulic seals of the booster. It is probably full, and drawing fluid back up into your intake manifold - hence the smoke.
3. The unit SHOULD be asy to rebuild. The hydraulic seals are almost the same as rebuilding a master cylinder, except that there will be a seal with a hole in it for the actuator rod to go through.
If you use the thing 100 miles a year or less you could live with it, or strip it to rebuild as the seals are normally a standard diameter and should be obtainable from most truck brake places. Only big snag I can see would be if the seals were non-standard (not likely) or the booster cylinder bore needed refinishing or sleeving.
Gordon