notamondayfan 44 Posted December 22, 2008 hey guys on the way to work this morn, my brake suddenly became very hard to press, and there seems to be a squishy sound coming from the brake pedal area. the brakes do work, but it no where near good enough, and its very hard. its almost like how it feels if i were to stall, if u know what i mean? anyone know what might have happened? thanks, dean Share this post Link to post Share on other sites
easypug 0 Posted December 22, 2008 Sounds like the servo assist isn't working. To test, pump the brake pedal till its hard with the engine off. Once it goes hard keep your foot on the pedal and turn the engine on. The pedal should go further down like under normal braking conditions. Share this post Link to post Share on other sites
notamondayfan 44 Posted December 22, 2008 and if it is that, would i have change the whole servo? or can parts be changed / refurbd? is there anything i can do today before setting back from work? obviously not going over 20 all the way back !! thanks, dean Sounds like the servo assist isn't working. To test, pump the brake pedal till its hard with the engine off. Once it goes hard keep your foot on the pedal and turn the engine on. The pedal should go further down like under normal braking conditions. Share this post Link to post Share on other sites
Rom 0 Posted December 22, 2008 Make sure the vacuum pipe is on the servo properly. If the unit isnt operating, it will probably be easier to just swap it out with another one. Im not sure if they can be rebuilt, they look sealed, and ive never tried. The brakes will still work ok if it is the servo, youll just have to put more effort in ! Loads of old cars dont have servos, and most race cars loose them also. Share this post Link to post Share on other sites
jengis 0 Posted December 22, 2008 The brakes will still work ok if it is the servo, youll just have to put more effort in ! Loads of old cars dont have servos, and most race cars loose them also. I dissagree. No real benefit for racers to remove a servo if the car is manufactured with one, and not something race car builders generally do at all. Probably best not to drive that distance but, hey! Each to their own! Not likely to bethe vacuum pipe disconnected/faulty as the engine would have ran noticably differently if inlet vacuum was lost. A new servo will sort it! DIYable for most people, but not expensive for a garage to do. Share this post Link to post Share on other sites
Rom 0 Posted December 22, 2008 Without wondering too far off topic. Its pretty common to remove servos when running dual MCs on race cars. Most pedal boxes dont allow use of servos ? All they do is make it easier to exert pressure on the pedal by using manifold vacuum to pass pressure between chambers internally within the servo. Which means you need to press the pedal less for the same force. A lot of new cars are over assisted, which is why you almost go through the screen when your not used to the brakes. The MC piston rod can still be moved in the same way with or without servo assistance. Its mechanically connected to the pedal, the travel doesnt change, its just harder to press without a servo. The effect is the felt most often when towing a car. The rear car has no servo assistance without the engine running, yet it still manages to stop just fine. You just have to stand on the pedal a bit more. Share this post Link to post Share on other sites
jackherer 543 Posted December 22, 2008 Race cars and cars originally designed with no servo will have different diameter master cylinders to reduce the required effort, a car with the servo disconnected will need much more pedal effort and isn't always a good idea. Share this post Link to post Share on other sites
Rom 0 Posted December 22, 2008 I didnt mean to imply it was a good idea. Just that it will still work, just with more effort required. Sorry if thats how its come across. Share this post Link to post Share on other sites
jengis 0 Posted December 22, 2008 Sorry for off-topic, My bad Yeah single seaters and fully prepped cars run no servo if using twin m/c's so I guess I shouldn't have questioned your comment about racers ditching the servo. Just not a good idea on its own. Trying to stay on topic...!... What is it that causes a pedal to have a bit of dead travel at the top? Air in system? Or the servo? I always thought it was the servo design but not sure. The 306 GTi-6 is solid from the top of the pedal, as are some other modern cars I have driven. Should the 205 be? Mine isn't! Share this post Link to post Share on other sites
notamondayfan 44 Posted December 23, 2008 all sorted, went to have a quick look under the bonnet to check the obvious things like brake fluid level and such, and spotted that the vacuum pipe had come loose from the manifold. luckily i had just been given a small tool set from a guy at work as a secret Santa present, unfortunately the tool kit came in bright pink colours!! Share this post Link to post Share on other sites
Rom 0 Posted December 23, 2008 and spotted that the vacuum pipe had come loose from the manifold. /me whistles.... Glad you got it sorted mate Share this post Link to post Share on other sites
