I need advice on improving my power brakes! I installed Willwood disc brakes in place of stock discs but cannot get enough help from my booster. At idle there is 8" vacuum and 2,000 RPM ups it to 20. But the assist doesn't stay, maybe a vacuum leak? I installed a vacuum accumulator tank - but the gauge shows vacuum going down as soon as RPM goes down. Thanks
Does your engine have a large cam? I have some really hi po engines that will still make 9 " of vacuum. You will need maybe 12".
yes it is I never did anything about it but try the accumulator tank I just ordered a booster and master for $115 Any installation tip or tricks would be appreciated.
I'd check the one-way valve at the booster before I dropped any money towards a new booster. You may only have to replace a three dollar connector. Devon
I'm sorry, please be more specific...when you pull what line off which component???? From what you've said so far, you have one or more of three possible problems: The booster diaphragm is bad, the booster o-ring seal is bad, the one-way check valve is bad. Devon
That is quite normal, there is no negative pressure in the intake manifold or the 3/8" rubber line with the engine off. You have a leak at one or more of the three points I mentioned, the failure of the check valve is what should be investigated first from a cost standpoint. Devon
Devon is correct. I also had a vacuum issue after installing a big cam. I purchased the SSBC electric pump only to find that after sitting for any lenght of time as soon as I power the ignition (before start up) the pump was running. Simple vacuum leak!! Just got use to the crappy pedal over time, really didnt notice the problem until the cam was put in...
You might want to consider installing a one-way check valve at your cannister if one did not come with the unit or you haven't already tried it.
Wildside I hope all is well and you have solved the problem with the new booster and master. However power brakes will always feel dead at 8in and were engineered to function at 16in. Disks flat need more fluid leverage than cylinders. The cam timing must be on the wildside to match your handle producing 8in or there's a problem causing low vacuum. That said, here are the 5 physical solutions: Greater vacuum storage and one way valves to save part of the 20in for later. Tough to use the vacuum to stop at a light-- restart and panic stop before the vacuum is rebuilt. A vacuum pump--If you go this way check the noise of the pump before you install it. Soundproof box ect. Greater power leverage. Have a double diaphram booster built. You can see them at any rod show-- the small block Chevys are notorous for this. Its not too expensive --a couple of hundred. Greater leverage in the fluid. A smaller bore master gives more leverage to the wheel cylinders. However petal travel is increased as less fluid is moved. Finally greater mechanical leverage petal to master. Hard to do in a modern car --unlikely you would like to modify this. That's all I know sometimes there's a silver bullet sometimes it takes a combination of above. Also its possible to jump a tooth on the cam and a misstimed cam shaft will also produce low vacuum. Hope your stopping as well as motivating! Chuck:TU:
