HWH 200 series, anomaly

[ihbond]

hwh 200 series jack (4 of them)
will draw diagram as this might get confusing

-----FRONT----
-----------------
(a)-----------(b)
-----------------
-----------------
-----------------
-----------------
(c)-----------(d)
-----------------
------BACK----

Assumptions: All levels are in operate (front and back), No Leaks, Fluid Full. All jacks will eventually go down (but not as designed). All jacks retract. RV in park. Only issues with front jacks, as both rear jacks go down when in rear raise position. Issue seems to be only the front jacks.
Steps are followed in order..

1) If i place the hydraulic joystick to the front raise position only jack (a) goes down.

2) If I place the hydraulic joystick to the right raise position both jacks (b) & (d) goes down

3) If i go back to the front raise position both jacks (a) & (b) will go down (notice how jack (b) finally works in the front raise position.

Any Ideas, is there a way to reset the control device. Perhaps clean the device is needed (have not looked yet)

Thanks for any insight..

[krivanj]

Call HWH and ask them. They usually are wonderful to talk to...

[ihbond]

Hi KRIVANJ.
Yea. did..Spoke with Frank (really helpful)
.they are sending me a new board..we are thinking the contact might be flakey, or push switches (Plungers or lack of a better name) might might not be engaging evenly.
8$ part, why not try the board first...
Thanks

[DAN L]

Originally Posted by ihbond

hwh 200 series jack (4 of them)
will draw diagram as this might get confusing

-----FRONT----
-----------------
(a)-----------(b)
-----------------
-----------------
-----------------
-----------------
(c)-----------(d)
-----------------
------BACK----

Assumptions: All levels are in operate (front and back), No Leaks, Fluid Full. All jacks will eventually go down (but not as designed). All jacks retract. RV in park. Only issues with front jacks, as both rear jacks go down when in rear raise position. Issue seems to be only the front jacks.
Steps are followed in order..

1) If i place the hydraulic joystick to the front raise position only jack (a) goes down.

2) If I place the hydraulic joystick to the right raise position both jacks (b) & (d) goes down

3) If i go back to the front raise position both jacks (a) & (b) will go down (notice how jack (b) finally works in the front raise position.

Any Ideas, is there a way to reset the control device. Perhaps clean the device is needed (have not looked yet)

Thanks for any insight..

be careful not to twist the chassis by operating a front and the opposite side rear jack. you can pop the windshield out by twisting the chassis.

[ihbond]

Hi Dan L;
How so ? at the same time I assume ? Typically I only adjust to get level...

[DAN L]

Originally Posted by ihbond

Hi Dan L;
How so ? at the same time I assume ? Typically I only adjust to get level...

even operating only 1 jack can twist the chassis...
so, be careful when your system malfunctions.

[Petro]

ihbond;

I had a similar problem on a 97 Adventure. If I remember I had to remove the top cover plate. I trimmed the carpet which allowed the plate to drop down. This gave the lever more range of movement. I also used a rat tail file to lengthen the slot that was not functioning properly. That solved my problem.

Good Luck;
Don

[ihbond]

Originally Posted by DAN L

even operating only 1 jack can twist the chassis...
so, be careful when your system malfunctions.

I typically get all 4's down first. But will now make sure that happens. Thanks for the tip!

[ihbond]

Originally Posted by Petro

ihbond;

I had a similar problem on a 97 Adventure. If I remember I had to remove the top cover plate. I trimmed the carpet which allowed the plate to drop down. This gave the lever more range of movement. I also used a rat tail file to lengthen the slot that was not functioning properly. That solved my problem.

Good Luck;
Don

Hi Don;
Well as it stands now, I am waiting for the new circuit boards, as the other one was just so warn. Figured start there first ($8 part).

I tried dielectric grease as well...BTW If anyone out there is thinking of doing this I would suggest not to..dont put dielectric grease on the contacts (thought that would work, but made it worse).

If the board does not help, I will investigate the space\void that is occurring.

Take Care
Ian

[KIX]

Originally Posted by ihbond

I tried dielectric grease as well...BTW If anyone out there is thinking of doing this I would suggest not to..dont put dielectric grease on the contacts (thought that would work, but made it worse).

dielectric grease, as you now know, is used to insulate rather than promote contact.

Your jacks should only work in pairs to prevent frame twisting. Either both front, both rears or both on either side. If your jacks are not operating in pairs you can twist the frame.

[ihbond]

Thanks Kix!
What i find interesting is if you operate (say the right sides) and put them 3/4 down and not touching, and then go back to the fronts and start putting them down, then the front right jack will have already had a head start and now be the only jack used to lift the coach.

From now on, I will make sure all 4 are down, before I start leveling, or is that not necessary ?

[KIX]

Ihbond, I understand what you are saying. I don't have the same series of HWH system as you have so I'm doing some guessing here. But, I think in the instance you cite, above, the right jack already partially extended would (or should) not actually lift the coach until the left front jack "caught up" so they would both lift at the same time.

[DAN L]

kix:
on my moho with hwh jacks one front jack can and will lift the moho if it is ahead of the other front jack thereby twisting the chassis.

[KIX]

Originally Posted by DAN L

kix:
on my moho with hwh jacks one front jack can and will lift the moho if it is ahead of the other front jack thereby twisting the chassis.

Is that the way the system was designed to operate?

[DAN L]

Originally Posted by KIX

Is that the way the system was designed to operate?

depends on which buttons i push... i can make it do what ever i want it to do.
i normally level side to side, then front to rear.

[Roadking]

ihbond: It's possible you have no problem, I'll try to explain..but it gets complicated. First an explanation and then my hypothesis...(or barely knowledgeable opinion).

The HWH system has "one-way" pressure valves in series with the hydraulic lines of each jack. These valves are similar to check valves but require a small amount of pressure to open. These valves are designed to allow a pair of jacks to operate equally only after the pressure of the pair has been equalized. This ensures that if pressures are not equal then the jack with higher pressure will not drop suddenly to the jack with lower pressure. For example, say you have jacks "a & b" extended with weight on them and then you want to extend jacks "b & d". In this case Jack "B" already has pressure on it and jack "D" has no pressure. Without these valves, once you applied the joystick to lift the "B & D" pair, jack "B" would collapse (or rapidly retract) until the pressure of "B & D" was equal. This is not good as it would result in frame twist. Hence, with different pressure, one jack in a pair can move while the other jack remains stationary and once pressures are equal then both jacks will operate. Even with no weight on a jack, it takes pressure to move the jack and one jack may move easier than another jack. This can be due to simple things like different resistance in the jacks due to seals,pistons, length of lines, wear, etc.

These different resistances can be seen when the jacks are retracted. During retraction all four valves are opened at the same time yet routinely one jack will store prior to the next, even if the jacks had the same exact distance to retract they will store at different times due to different resistances in the hydraulic circuits.

Therefore, it is possible in your situation that jack "A" and the associated hydraulic circuit consisting of lines, valves, etc., simply has less resistance than the jack "B" circuit, hence jack "a" extends first. Once a small amount of pressure is applied to jack "a" (i.e. it touches the ground), then jack "b" will extend while jack "a" holds with the small amount of pressure. Once both jacks touch the ground then they will both lift as designed. My system is a 610 which is automated and I have watched my jacks operate in this manner routinely, i.e. one jack of a pair that is extending routinely touches the ground prior to the second jack extending. Once they are both on the ground then the lifting begins.... as designed.

Go to step 1 again and let jack "a" touch the ground... almost immediately after it touches the ground it should stop moving and jack "b" should extend until it touches. Once both jacks are now on the ground the pressures will equalize both jacks should lift in unison. If jack "a" is on the ground and continues to lift while jack "b" is not on the ground...then you have a problem. HOWEVER, given your explanation of steps 2 and 3, I doubt this.

Sorry for the long post.. and good luck.

Good luck.

[Lt46]

Roadking,
That post took some work and is exactly how I understand HWH hydraulics to work. Nice job!

[ihbond]

Hi there Roadking;
Thank you for the well thought out reply!

WHen I get my PCB board today or tomorrow I will try to prove\disprove the hypothesis by applying a little pressure on the ground, enough to lift but not twist\bend.

Thanks to everyone who contributed to this thread it was helpful.

Ian

[ihbond]

Hi ROadking;
well I got the parts from HWH (PCB JOYSTICK) and put it back in. Also fixed a broken 2 wire molex that is used for jack alert when lowered.

So ....I tried lowering (a), & (b).

(A) would go down then would start to lift the coach about an 1" then (B) went down to try to equal out. It seemed as though (A) was winning the race.

Perhaps a line bleed is in order ?

Ok for my next question..Where is the level bubble on a 99 winnebago chieftain , as I want to adjust level indicators.