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Topic: HWH hydraulic jacks. (Read 457 times) previous topic - next topic

HWH hydraulic jacks.

Happened this morn to a neighbor (you know the kind) getting ready to leave, who kept starting/stopping the coach numerous times/ on and on. I finally heard THAT SOUND of a jack dragging when he tried to move the coach. Being curious, I could hear him cursing and grunting under the front end, finally left, no wave. So WHAT happened? Did he drain fluid to get the jack up, or was it a leak that caused the problem in the first place? Here's a bad pic:
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: HWH hydraulic jacks.

Reply #1 –
Mike,

No way for us to know the root cause of the jack not properly retracting-- could be a bent piston, weak or broken spring, failed solenoid, etc.

To release the hydraulic pressure on a jack, go to the HWH pump/reservoir. Unscrew the "T" handle on the offending jack a couple of turns (do not remove).  That will release the hydraulic pressure on the jack. If bad spring, bent piston, etc he will still have to pry the jack up.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: HWH hydraulic jacks.

Reply #2 –
Quote from: mike leary –
Which explains the human noise under the coach. He'd tried to bleed it, judging from all the fluid and then took a screwdriver to pry it up.

He could have driven off the jacks forward and they would have flipped up extended.  Then cracked the valve later
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: HWH hydraulic jacks.

Reply #3 –
[quote author=wolfe10 link=msg=228599 date=14 To release the hydraulic pressure on a jack, go to the HWH pump/reservoir. Unscrew the "T" handle on the offending jack a couple of turns (do not remove).  That will release the hydraulic pressure on the jack. [/quote]

When the "T" handle is released, does it daylight fluid?
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: HWH hydraulic jacks.

Reply #4 –
No the pressure holding the jack down is realeased and the oil flows back into the tank
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: HWH hydraulic jacks.

Reply #5 –
Quote from: Caflashbob –
He could have driven off the jacks forward and they would have flipped up extended.  Then cracked the valve later

If kick down jacks, he could have done that-- I still would release the hydraulic pressure and get them up first.  Besides, the jack down alarm would continue to sound!
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: HWH hydraulic jacks.

Reply #6 –
Quote from: John Haygarth –
No the pressure holding the jack down is realeased and the oil flows back into the tank
So did the dweeb bleed the lines to daylight for nothing, or would a leak have caused the problem?
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: HWH hydraulic jacks.

Reply #7 –
Mike,
I would expect a leak to relieve pressure thus causing the jack to raise.
Jerry & Nanci
1999 U270 34'WTFI
2011 Malibu
A smart man knows what to say, a wise man knows when to say it.

Re: HWH hydraulic jacks.

Reply #8 –
Quote from: mike leary –
So did the dweeb bleed the lines to daylight for nothing, or would a leak have caused the problem?

No, a leak would not cause the jack to stay extended.  They are hydraulic extended, spring retracted.

And using the "T" handle to release pressure results in zero leak-- it just goes back to the reservoir.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: HWH hydraulic jacks.

Reply #9 –
Quote from: wolfe10 –
If kick down jacks, he could have done that-- I still would release the hydraulic pressure and get them up first.  Besides, the jack down alarm would continue to sound!

Not that I remember as the jack is not down.  Just extended. 
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: HWH hydraulic jacks.

Reply #10 –
Bob, I seem to remember when we had that kick down type that as you said the alarm would sound only if verticle but not extended as the alarm is triggered from a mercury switch that has to be vertical. Extending does not do that. But, having said that there is a very good chance that  that you could bend the shaft enough to cause more problems so allways best to "get it up one way or another"
JohnH

Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: HWH hydraulic jacks.

Reply #11 –
Quote from: John Haygarth –
Bob, I seem to remember when we had that kick down type that as you said the alarm would sound only if verticle but not extended as the alarm is triggered from a mercury switch that has to be vertical. Extending does not do that. But, having said that there is a very good chance that  that you could bend the shaft enough to cause more problems so allways best to "get it up one way or another"
The neighbor must have seen his warning light come on when trying to retract, which (I guess) is why he kept starting the coach over and over, not knowing, with the key on, the HWH console warning light & dash warning would work without the noise and drain on the batteries.
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: HWH hydraulic jacks.

Reply #12 –
Quote from: John Haygarth –
Bob, I seem to remember when we had that kick down type that as you said the alarm would sound only if verticle but not extended as the alarm is triggered from a mercury switch that has to be vertical. Extending does not do that. But, having said that there is a very good chance that  that you could bend the shaft enough to cause more problems so allways best to "get it up one way or another"
JohnH

Either on purpose or by accident I have driven off a lot of hwh jacks without incident.  Big shaft.  Big pivot bolt on top.  Two heavy springs for retraction.
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4