Been doing a bunch of work on our van, and thought some of it may be of interest to folks here. Figured I would start a few threads to discuss the changes.
One of the issues that has been a bit of a bother to us was the foot pressure required to hold our van still offroad when descending steps (especially for all sub-100lbs of Amy). This was exacerbated by our 37" tires.
Then when our engine died last fall and left us without much in the way of vacuum assist on the brakes to stop while descending a hill the brake issue was raised again.
Some reading and research revealed all the nifty expensive new rotors, calipers, pads, etc. Unfortunately money is expensive, and these solutions too quite a bit of it. This also wouldn't address the lack of significant vacuum storage on engine failure, nor the apparently limited lifetime of some vacuum pumps (our van is diesel) that some folks experience.
We decided to go the route of the E450 and pickups, and convert our brake system over to a hydro-boost system (using power-steering fluid to multiply brake-pedal pressure, rather than the huge vacuum drum in the van stock). The units also have a hydraulic pressure reservoir for a few hydraulic assisted brake pushes after the engine dies, at higher assist rates than the vacuum reservoir system allows.
We stuck with the stock master cylinder since it is sized appropriately. A few adapters to match it to the hydroboost unit from an E450, some hydraulic hose and fittings, and a day of tinkering to get everything massaged around in the engine compartment.
After installing everything, including a much larger power-steering fluid cooler, I refilled the lines, purged everything and re-bled the brakes. A pressure gauge on the front calipers coupled with a bathroom scale on the brake pedal shows about 33% more brake pressure for the same foot pressure compared to the stock vacuum booster.
Driving test yields noticeably better braking, without being too sudden. Total cost was about 300$ with all new hydroboost, lines, fittings, and fluid.
This improvement can still have the standard improvements applied as well (rotors, pads, calipers, etc).
There is a bit more detail and background on our website at http://www.badgertrek.com/sportsmobi...e.shtml#Brakes