Guest Spargo Report post Posted August 21, 2006 Can you please explain to me the difference between the systems, and the pros and cons of each? I know how each system is hooked up and connected, but i'm not sure how brake feel / consistency and that sort of thing are affected. Quote Share this post Link to post Share on other sites
westy 614 Report post Posted August 21, 2006 Ummm...Thay are all hydraulic. The 'Vacuum' is a vacuum booster used to lighten the effort on the pedal. Quote Share this post Link to post Share on other sites
Guest Spargo Report post Posted August 21, 2006 (edited) The first pic shows a 733i setup, with a "brake bomb" that retains pressure. the "booster" attached to the master cylinder has lines going to the power steering pump, so i'm assuming this is a haydraulic booster, rather than a vaccuum setup? Edited August 21, 2006 by Spargo Quote Share this post Link to post Share on other sites
westy 614 Report post Posted August 21, 2006 (edited) Ha,I see where your coming from now,but I have no idea what your on about. Edited August 21, 2006 by DirtySix Quote Share this post Link to post Share on other sites
CaM 0 Report post Posted August 21, 2006 commonly found on e28s if I'm not mistaken? would be much of a muchness, although, on vehicle running a fairly wild cam, the hydraulic setup could hold merit over the vacuum? being that high lift/long duration cams aren't the best at creating a vacuum... alot of cars with such cams have to run a vacuum tank to store vacuum that's able to be scavenged on the over-run, with a pcv valve to stop the engine drawing the accumulated vacuum back, to be able to cope with braking demands etc. would be interesting to see... hydraulic on abs system = still reasonably spongey. could be the left hand mounted booster with linkage system's fault though. I understand that it's a trademark of bmw, so yuh Quote Share this post Link to post Share on other sites
kerrynzl 3 Report post Posted August 22, 2006 The middle photo shows a vacuum brake booster, The drawing looks like some sort of fluid recirculation system??? I cant see any high pressure lines [they wouldn't to the reservoir] Can Somebody enlighten us [or put us out of our misery] Quote Share this post Link to post Share on other sites
Guest Spargo Report post Posted August 22, 2006 Kerry, I've not got a pic of the whole system. The vaccuum pic is to show the difference and what i was on about. The High pressure lines go to the p/s pump, and attach to the booster, which is behind the master cylinder, the bomb shaped thing holds pressure for 2-3 brake stops while the engine is off. Quote Share this post Link to post Share on other sites
Guest Denny Crane Report post Posted May 13, 2007 Some more pics Quote Share this post Link to post Share on other sites
bimmerbaz 1 Report post Posted May 13, 2007 BMW did not have much room under the bonnet so they came up with the idea of one hydraulic pump to run the power steer < self leveling>and brake boost. The system was refered to as the H31 sytem. The fluid in it was usually a special hydraulic fluid and the sphere was filled with nitrogen to allow you to have boosted brakes if the motor stopped while driving.Unfortunatly many people did not fill the systems with the correct oil and used ATF. This caused the seals to fail and caused many costly repair.It performs the same job as a vacuum booster but takes up less space and could be intergrated with other systems.The system is monitored and has a self check system to let you know when the pressure is faulty. Quote Share this post Link to post Share on other sites
BM WORLD 1260 Report post Posted May 13, 2007 i have both systems in bmw's i own , i prefer the vac system for a tight pedal feel , but both work ok for pulling up . the e28 m535i runs hydro system , pretty reliable , just the brake bombs fail and make the brakes feel usless but they still work just delayed feel . only ever had one hydro booster leak , but brakes still worked ok , only took 45mins to swap over with another . they can run happily on atf trans fluild . Quote Share this post Link to post Share on other sites
drifty325i 0 Report post Posted May 13, 2007 i have both systems in bmw's i own , i prefer the vac system for a tight pedal feel , but both work ok for pulling up . the e28 m535i runs hydro system , pretty reliable , just the brake bombs fail and make the brakes feel usless but they still work just delayed feel . only ever had one hydro booster leak , but brakes still worked ok , only took 45mins to swap over with another . they can run happily on atf trans fluild . How hard would it be to intertgrate this into an e30 ? anyone? This is the way ill end up going but want the info first lol. Do you think i can squeeze it pate the v8? poss on an angle? Quote Share this post Link to post Share on other sites
