mos 1 Posted June 26, 2007 Hi, regarding brake servo's or boosters as the rest of the world seems to call them. i never had one go faulty on me but i always thought that it is the type of part that either works or it doesn't. but after doing a search on here and the wider internet i an not so sure. can someone just confirm for me that servo's can actually weaken or partial fail as well or was my initial opinion correct and they either work or suffer a total failure. thanks mark Share this post Link to post Share on other sites
Pugnut 9 1 Cars Posted June 26, 2007 i guess they are like anything else , the f up or completely f up !! how i've always tested mine is with the engine off pump the brake pedal solid and keep your foot pressed on the brake pedal while starting the engine . as soon as the engine starts the pedal should drop a bit as the vacuum builds up. Share this post Link to post Share on other sites
mos 1 Posted June 26, 2007 i guess they are like anything else , the f up or completely f up !! how i've always tested mine is with the engine off pump the brake pedal solid and keep your foot pressed on the brake pedal while starting the engine . as soon as the engine starts the pedal should drop a bit as the vacuum builds up. thats the problem when i test it statically i do get some vacuum, so its at leasts partially working but on the move the car feels like there is no servo assistance which after changing all the pipwork one valves and seal, one and two takeoffs on the inlet manifold etc (its an modded s16 engine running bodies) has lead me to the conclusion that either the engine does not produce enough vacuum or the servo, although producing some vacuum is not able to generate enough. the problem is uptil this point in time i always though a servo either works or it doesn't with no middle ground. but perhaps i am wrong with this assumption and you can infact get a"weak servo" which is why i am asking the question can servo's go "weak" or do they just either fail entirely or work perfectly? thanks mark Share this post Link to post Share on other sites
Richie-Van-GTi 71 2 Cars Posted June 26, 2007 what are your exact symptons, someone may of had the same and be able to pin point the fault. Share this post Link to post Share on other sites
jackherer 543 Posted June 26, 2007 I've had one leak badly enough to make hissing noises and mess the engine idle up but it still worked fine while braking. Share this post Link to post Share on other sites
