: Hydraulic assist information found


Way
06-03-2002, 03:04 PM
O.k. Didn't really relate to the full hydraulic post that I had earlier so I figured I would start a new thread that is relevant to the topic. Went to Avalanche this morning and learned that they send everything to HOWE and then install it for you. There is a tractor supply next to the facility that they get the lines from. They really know very little, and basically just weld a bracket on axle and make a custom mount for pump and add a nice percentage to the cost of the Howe system.

Here is some information about our rover systems that I found in my tech manual. The pump is a Hobourn Eaton V-Series 200. Operating pressure straight ahead at idle is 7 kgf/c^2 (99.54 PSI). At full lock at idle pressure is 28 kgf/cm^2 (398.16 PSI). At full lock at 1000 rev/min operating pressure range is 70-77 kgf/cm^2 (995.4-1094.9 PSI). The pump GPM right now is around 2.88 from what my basic calculations yield.

If you want Hydraulic assist you will need to take your box, pump and resevoir off of vehicle and send to Howe. They disassemble and modify existing parts so that GPM is as high as possible. Because of the small output of the pump it is most likely that a 1" or 1.5" ram will have to be used. The problem with going to a 2 or 2.5 is that the pump cannot press the volume quickly enough to meet ram requirements (under panic operations ram could bind if steering to right quickly then left or vice versa,etc.). The output of a howe pump is 1300 PSI and puts out close to 5 GPM (and 1600lbs of force). Because of this a 2"+ ram can be used.

Since it costs $250 to have our pump modified and rebuilt it makes sense to me to pay $325 for the bigger pump that Howe uses. Downfall is that a bracket will have to be made to attach their pump to our engine. Their pumps are a modified Saginaw unit. I do not know if rover ever used a saginaw pump in their vehicles with the 3.9 liter motor, but if they did I am sure a factory bracket could be purchased.

The rams (although) filled with fluid still have friction in them especially under high load situations. Because of this a filter is used. For this they use a modified Toyota filter. They can make it remote resevoir or have it attach to the pump I think. Without this the fluid will turn black very quickly according to Howe.

When they tap the box they use one of the three fiting sizes. #6, #8, or #10. There kits do not include lines so a local hydraulic shop will need to make them. They recommend the blue 2000 lb (9000 lb burst rated) line with steel fitting only.

The cost break down is as follows ballpark.
$475 modified box
$325 Pump (or have yours modifed for $250)
$150 for filter system
$186 for ram (regardless of size)
$? Shipping costs
$150ish for custom lines in your town
=1286ish + shipping both ways (does not include dismantle or fluid replacement)

Kind of expensive, but if used on the highway it is recommended to have the GPM and ram match. Plus I can't imagine most of us can tap our own box and modify the inside to allow unit to work. Super nice people at tech support there.

If anyone decides to do this ( I am saving now), send to the attention of Chris and send to the Howe address. I called the 1-619-561-7764 number. This set-up can turn 44 inch tires no problem at very low pressures. For our heavy vehicles (Range Rover owners like me) drop that size down a bit to get a more accurate reading. Even at 7000lbs with 37" tires this system should have no problems. I asked about single throw because I already have the bracket made on my axle, but for others, I recommend a double throw. Single throws have a different thrust (push or pull) each way. the pull is always less becasue of the reduction of cyclinder area due to piston rod. Double throws are equal both ways.

Before you send in system. Mark center line of tie rod. Turn to the full stop left and put a mark on axle housing of how far tie rod line mark went. Now turn to right. Again measure how far tie rod line mark went. Place mark on axle housing. Move vehicle steering to center. Measure the distance from tie rod mark (in center of tie rod) to left side. Do this for right side also. Provide these measurements when sending rover parts for Howe so they can build the custom ram to suit your vehicles geometry etc. With all of the changes we do to our vehicles I recommend everyone perfroms their own calculations. The ram will releave a lot of the pressure on the sector rod in our units and most likely improve the longevity of our units. Not to mention allowing us to pick any line while rock crawling

Way:D

RockRover
06-03-2002, 08:25 PM
Good Shieat Adam! And timely too! I was JUST starting the dig process to find out what our little pumps put out. I was really hoping to use the stock pump to see how the 2.25" double throw ram does...But from your information, it looks like the Lee pump I already bought will have to be put in. The issue that I see, is that the pump now has two pulleys on the output shaft...One off the crank and the other acts as a tensioner for the alternator. I think you could get away with only using one pulley, and tensioning the alternator back (or use a smaller belt).

I know my Lee pump can be tweaked for just about any GPM and PSI so I better get in touch with Lee and find out what needs to be done?It looks like it?s not a tough job to do it yourself with the Lee (screw-out cap and snap ring)?However the LR pump has a crimped (stamped) cover that would need to be pried off and then (somehow) re-crimped?Looks real cheesy to me, but who knows?

Thanks again Adam...Good stuff man!

BTW, do you still want the box? She's ready to go.

--D

Way
06-04-2002, 11:22 AM
Yep still want your box. Going to install that while I save for some hydraulic pieces. Mine leaks about 1/2 cup sitting in the street per day! Station had a post in the full hydraulic thread. Sounds like he is a good source for parts at a more economical price. If one was to replace the pump as well, I imagine that he could get a system set up. It will be interesting on the pulley configuration. Also I am not sure as to what pulley size to get when it comes time. Several are offered.:confused: I will have to pop the hood again and take a closer look. Curious if a double pulley is offered or can be adapted to a howe or similar pump???

Way

RockRover
06-04-2002, 12:17 PM
Originally posted by Way
Curious if a double pulley is offered or can be adapted to a howe or similar pump???

Way

Me too. I'll pull mine later this week and let you know.

I'm surprized that Howe is charging so much to increase pressure and GPM. There's a great tech write-up on the Texas Offroad site showing excatly how to do it yourself...It's a Saginaw pump (GM) but it looks like about a 1hr job.

--D

Way
10-08-2003, 08:57 PM
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Way
10-08-2003, 08:58 PM
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Way
10-08-2003, 08:59 PM
3

Way
10-08-2003, 09:00 PM
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Way
10-08-2003, 09:00 PM
5

Way
10-08-2003, 09:01 PM
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Way
10-08-2003, 09:02 PM
The last picture is of a heim joint holding the shaft.

Way
10-08-2003, 09:03 PM
trac bar mount

Way
10-08-2003, 09:03 PM
shaft

Way
10-08-2003, 09:04 PM
resevoir filter

Way
10-08-2003, 09:04 PM
pass side set up

PTSchram
10-09-2003, 07:35 AM
Again, Adam, thank you!

The later ZF pumps are able to be disassembled, but a real PITA to reassemble. The early pumps are indeed crimped-I doubt they could be easily disassembled at home.

Flow/revolution and pressure data is fairly easy to find, but ZF claims that nearly everything about their pumps is proprietary-finding bearings was very difficult as the drawings for the bearings (on paper with title block for the bearing company) bear a statement that the info belongs to ZF... Don't ask me how I got the drawings, or a set of bearings:flipoff2:

Saginaw pumps can be mounted to serpentine belted engines fairly easily by merely bolting suitable sized pieces of aluminum stock to space the pump to mate to the belt/pulleys. I have sketches, but haven't finished it as other things seem to break!

I'd have a sag pump on my Rover, except for the pulley. A Dwebber sent me a blowed up pump to try to remove the flange... I bent my hydraulic press (again) trying to remove it and my snap-on harmonic dampener pulley didn't budge it. Yeah, I know, I haven't worked hard enough.

I am unaware of a seven groove serpentine pulley that will mate to the relatively small diameter shaft of the pump I have. Anybody know of one? I believe the shaft is 5/8 with an unknown taper.

I chose a pump with integral reservoir as I wanted to maximize space for secondary battery and perhaps clearance for a snorkel or air compressor.

I have a spare (leaky) gear box that I someday intend to drill/tap for hydro assist. Tuffjarhed seems to think we can do it pretty easily. I'll have to direct him here to this thread.

Peace,
Paul

green rover
10-09-2003, 10:35 AM
in those pics. is the ram mounted to the frame and then to the steering linkage? i always thought if you did that it would tend to pull the steering box off the frame after long term use?

Way
10-09-2003, 01:37 PM
Your welcome Paul, I use a howe pump so that there is not any confusion.

Green Rover,
The ram has a mount on the frame and the other end is mounted to the pitman arm. The frame is very beefed up. I have seen several people do this in the past with long term success. The pic is small but hopefully the full view front end pic does a descent job of the system.