The simple answer is yes, the pedal (or hand lever if hand controlled) moves a valve inside the hydro unit to direct the flow of oil from the hydraulic pump to the hydraulic motor(s). The PUMP always turns in the same direction and oil flow through the pump is always in the same direction. The VOLUME of oil flowing through the PUMP is always the same (for a given RPM). When the direction control pedal (or lever) is in NUETRAL, all the oil output from the PUMP is directed through the valve and dumped straight back into the sump cavity of the tranny case. When the control pedal (or lever) is moved to FORWARD or REVERSE, the control valve moves and begins flowing SOME oil through the DRIVE MOTOR(s) in the correct direction to make the motor rotate for the corresponding direction of travel for the machine. Depending on how fast you want to go, you will move the pedal a little or a lot. If you move it a little, you will go slow (and most of the oil will be dumped right back into the sump with just a little oil flowing through the motor). If you move the pedal all the way to the end of its travel, you will go fast (with practically ALL of the oil flowing through the motor and very little being dumped directly into the sump. I should point out that after the oil passes through the motor, it is dumped back to the sump. There are provisions in some hydro units to direct oil through a filter (either external or internal) so that debris and metal flakes can be trapped, but essentially, what I described above is the way hydros operate (generically). The "dynamic braking" of a hydrostat is due to the hydraulic principal that a liquid can not be "compressed" (it can be "pressurized" but not compressed to to a smaller volume), and in that respect, when you flow oil through a hydraulic motor at a given "flow rate", the motor will only turn as fast as that volume of oil flow will allow it to turn, regardless of load. When you "let up" on the pedal (or lever), you decrease the amount of oil flowing through the motor and thus the motor speed MUST also decrease and the vehicle speed is retarded.

No great words of wisdom for you, but a couple of thoughts. For my older boys we bought the older one a subaru wrx and middle one a used saab 9-3. While they both have been amazingly trouble free, when they do need work the things that are wrong need to go the dealer and it's been expensive. In particular with the Saab - they don't sell them anymore so parts are pricey and hard to come by - some impossible. That said, son #3 now has his temps and I've decided he can only buy American or Honda or Toyota. Looking at a several year old Ford Escape with AWD - not real sexy, but safe and functional. I personally love a new car, and have leased my last two vehicles. I drive them three years and take them back! My DH is a drive to the ground guy, actually takes pride in how many miles he can get out of a car. I believe BMW includes all the maintenance on their cars so you have to factor in those fees you'll also have to pay on a different car that probably will need some work. I'd keep the BMW, cancel the collision insurance on the Jeep since it's so old, and buy the girls a decent enough car that it will last at least 6 years. I think the 2010+ Fords are all good quality, and reasonably priced. I like the Ford Fusion. I also am a huge fan of Honda Accords and Civics. You should be able to find a fairly decent one for under $10,000. Goodluck, teen drivers are not for the faint of heart.

Some teens like to travel, don't. Some teens are very honest, some just like to please friends and relatives and get what they can/want. I have known both types since I have been extremely active with teens for many years. Just dealing with youth groups is a great way to know them. I and would do it all over again. Since most of us do not know others here except by visiting on line, we should be able to form our own opinions and not get shot down. I found that out the hard way, several times.

yes, the oldest has add... which I work with to upteenth degree. We actually already have the homework rule... ours is more like even if you dont have homework you have homework... you have to review what you did in school that day to make sure that you understand everything. Which, is why I find it so frustrating that he or rather they lie about having homework. It is not like they get out of doing work, they just end up in trouble for lieing and not doing their homework. It is ridiculous in a lot of ways ... why spend an hour reviewing everything from the day when you could have spent 15 minutes doing the assignment the teacher gave you. They are just playing every angle that they can and unfortunately it's working on a lot of fronts and I am exhausted. For example: the kids were at their moms house this weekend. The oldest had a report to do. I meet BM at 6 monday morning to take kids to school and oldest didnt do his report. I asked if BM knew and he said "well I asked her if I should finish at your house and she said I guess so" Ofcourse I am highly irritated because we had a very specific conversation on satureday about what he needed to do. And, ofcourse, I make him sit there and do his report. But, to top off the entire deal I show DH what he didnt do... he gets onto oldest ss about it makes a big deal. But then I have to go to school that same evening (report did not get finished before school which I made sure DH knew) and I dont get home until after 9 and he didnt do the first thing on the report and DH says that he didnt realize what he needed to do. So, I end up staying up with ss until late late to make sure the report got done. And then, the next morning DH gives the grounded boys doughnuts even though it is his own rule that when grounded you dont get treats. I don't know... I feel like they are doing it to test me sometimes. It's not like anyone else is holding them to right and wrong and doing what they are supposed to do. (well I suppose that is unfair DH does back me up but i feel like if I didn't say this is the problem it wouldnt be brought up) Really, I honestly feel like they are testing how far they can push and I will still stand strong... but then I feel like maybe they are starting to have an attitude of you arent my parent that has never really been an issue before because they weren't teenagers. i tried to disengage tonight and just let DH handle everything but that sooo didnt work... it is not in my nature. I tired to busy myself in my room organizing... I didnt ignore them, I helped them with homework and answered questions but my goal was to make sure that DH made sure they got their homework done and made sure they werent just wandering around doing nothing... but i couldnt help it... I couldnt just watch oldest ss playing with the girls knowing that he had a stack of homework on his bed... ugggghhh it pretty much boils down to I am frustrated!!