Hi all, does anyone know a simple solution to running an electric brake vacuum pump for servo as i'm now running jacked open throttle so i can't generate vacuum from the inlet manifold. I've been looking at the UP28 vacuum pump fitted to vauxhall signum's and volvo s40-s60. I was thinking about running this in to a resivoir of approx 1/2 litre then to the servo its self with a timer that runs for 10 seconds after each press of the brake pedal. Any ideas would be appreciated as this is a new problem to me and there doesn't appear to be alot of info out there. Any pump suggestions would be good.Not to keen on straight through rod as feel could be heavy unless anyone knows different. Thanks .

 

Any ideas?

 

Any reason why you can't/don't want to delete the servo? That's normally how it's done. Can feel a bit heavy at first but you get used to it. Depending on what you're driving you can mitigate that via a different master cylinder anyway. Pad choice makes a big difference too.

If you did want to try a vac pump the easiest way to do it would be to connect it to the servo via the existing one-way valve. No need/point for an external reservoir - if the donor car doesn't run one then the inference is that the output of the pump is enough to keep the servo supplied. Obvious way to engage/disengage would be via vac switch rather than timer.

 

Thanks for reply. I'm still using the standard servo on Sti2 at the minute. The reason i didn't want to go down the rod route was the effort in the pedal.The car is used for hillclimbing and sprinting so brakes need to work from the get-go. I'm running prodrive 330 brakes with ds2500 ferodo pads and when the vacuum runs out the effort needed is huge. I've looked at the up28 pump but have heard it can burn out if run constant and the reason for the resivoir is to avoid any variation in pedal feel. I like the pressure switch idea and am thinking this could be mounted in the resivoir to engage pump and should reduce pump run time. Ideally i'm looking for a set-up that someone knows works as the pump ain't cheap. If you know of another pump that could be used it would be appreciated.

 

Can't help you on the pump I'm afraid - but don't discount an unassisted setup, I prefer it. Proper servo delete should be easier on your foot than a servo that's run out of vac so your experience so far may not be representative.

 

my bro has an american pump for sale that connects direct to the brake servo didnt get used much think he wans 150 for it, ill try and find make out

 

I've managed to get a vacuum pump from an audi rs4 and a vacuum switch thats adjustable from -.2 to -1 bar so will be trying this out over the weekend with no resevoir in the system and see if this provides a stable brake feel. Both parts cost £110 in total so fingers crossed.

 

I would use a diesel alternator, most have a vac pump built in.

 

I wasn't convinced a diesel alternator would work without reducing the pulley diameter as the rev range is twice as much on a petrol and there is also the problem of the oil feed to and from the pump. I have a transit here but was loave to try it without hearing from anyone that has done it succesfully.