Jacks up or down?

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Tom

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Since our coach sits in storage for long periods, should I put the jacks down and take a little weight of the tires, or does that not help?
 

Karl

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Tom,
With radial belted tires (or tyres, as you would call them) It doesn't matter much as long as they're not standing in some hydrocarbon or oxygenated fluid, which would soften and weaken the affected area. You may experience some vibration because they will be slightly flat-spotted when you start out again, but it's not nearly as great a problem as it was with the older, bias-belted tires. The flip side of the coin is that you would be keeping constant pressure on the seals of the jacks if you were to use them. I would suggest using some substantial jack stands and let them take the weight off both the tires and the jacks.
 

Tom

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Thanks for that info Karl. It's a long time since I spelled tires that way  ;D
 

Ron from Big D

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Tom:

      I keep mine on the jacks all the time it is at home.  I have never had a problem with the jacks as a result, even though as Karl says, there is constant pressure on the seals.

Ron from Big D

p.s.  How do you put in an automatic signature to the messages?  Haven't figured that out on this site.  There is nothing in the profile.  I do realize though that your image and identity is off to the left.
 

Tom

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Thanks Ron. I hadn't though about pressure on the seals until Karl mentioned it.

To add a signature, look at this message.
 

Ron

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wiztom said:
Since our coach sits in storage for long periods, should I put the jacks down and take a little weight of the tires, or does that not help?

It doesn't really make any difference with todays tires.  The tires may have a flat spot for a short distance but that will correct itself.  The hydraulic systems  will not suffer any either.  If in a very humid area the extended jacks may corroide on the extended cylinders it left too llong. A wipe down with HYD fluid shhould prevent that.  DO NOT wipe cylinders with silicone.  Not good.
 

Jim Johnson

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(( DO NOT wipe cylinders with silicone.  Not good.))

That is just opposite of what a RV tech told me the last time I was in the shop.  He did not say to "wipe" them down but to spray them with silicone.  Please explain your reasoning.

 

Gary RV_Wizard

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I too am familiar with the mantra that says "no silicone on the jacks" (reason: silicone can contaminate hydraulic fluids), so was momentarily surprised to read in my PowerGear jack owner manual that I should if the jacks are left in the "down" position for awhile I should periodically spray the exposed sliding portion of the jack with silicone to protect it from corrosion.  Apparently PowerGear is confident that the seals around the ram are adequate to prevent any unwanted silicone from reaching the reservoir.  After all, if the seal is keeping the hydraulic fluid in, shouldn't it also keep the silicone out?

Is this perhaps yet another case where "campfire wisdom" is sounding an unnecessary alarm?
 

Ron

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As it was explained to me during a class I took when I was still employed the Silicone can contaminate the Hydraulic oil but also cause the hydraulic oil not to coat the cylinder and seals thus creating a contiion that will cause leaks.  The recomendation was to use the same oil as is used in the hydraulic system.

BTW the class was being presented to engineers and was presented by a engineer that specialized in hydrualic systems. 
 

Gary RV_Wizard

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No doubt the engineer knows what he is talking about, but does the advice apply in this context?  We are talking about silicone applied EXTERNALLY, to a part that is already directly exposed to numerous harmful substances, e.g. water, various road oils, exhaust fumes, etc.  Is the silicone any more likely to get past the seals than one of those other, equally (or even greater) contaminating substances? Maybe silicone oils have tiny molecules that sneak in where other substances do not?  I don't pretend to know -  just conjecturing.

My guess is that the risk is probably very low.  I'll likely use hydraulic fluid to wipe down the jacks when convenient to do so, but do not think I will lose any sleep if a spray of silicone gets on theer too.
 

Ron

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Yes we are talking about applying the silicone externally.  Based on the reputation of the individual giving that presentation I avoid silicone on hydrualic systems as well as using any silicone products on vehicle finishes.
 

Karl

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I wouldn't have a problem with either hydrsulic fluid or silicone, but definitely stay away from Teflon sprays! Teflon bonds with the metal and itself and you could build up a layer that may prevent your jacks from retracting. Remember, we're talking about essentially zero clearance between the seal and the shaft. Same applies to towbars!
 

John From Detroit

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Ron said:
Yes we are talking about applying the silicone externally.? Based on the reputation of the individual giving that presentation I avoid silicone on hydrualic systems as well as using any silicone products on vehicle finishes.

I am looking through some old posts and came across this.. Since I park jacks down and AM having a problem it's of interest to me

If memory serves me, and memory can be a bit flakey here, there are basically two kinds of hydralic oil,

One is petrolum based oil, simular in many ways to brake fluid, jack oil, transmission slush, ur, fluid, and the like (all are variations on basically the same product) and the other is silicon.  I've seen it offered as brake fluid, VERY STRONG WARNINGS NOT TO MIX THE TWO types of fluid, seems they do not play nice together

Thus, I'd go with the engineer's suggestion.. Whatever jacks the jack, that's what you wipe it down with

As for my problem.. I'll fix next month at a regular scheduled shop session (Routine, Plus some final sales stuff, Plus whatever needs fixing)
 

blueblood

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John In Detroit said:
I am looking through some old posts and came across this.. Since I park jacks down and AM having a problem it's of interest to me

If memory serves me, and memory can be a bit flakey here, there are basically two kinds of hydralic oil,

One is petrolum based oil, simular in many ways to brake fluid, jack oil, transmission slush, ur, fluid, and the like (all are variations on basically the same product) and the other is silicon.? I've seen it offered as brake fluid, VERY STRONG WARNINGS NOT TO MIX THE TWO types of fluid, seems they do not play nice together

Thus, I'd go with the engineer's suggestion.. Whatever jacks the jack, that's what you wipe it down with

As for my problem.. I'll fix next month at a regular scheduled shop session (Routine, Plus some final sales stuff, Plus whatever needs fixing)


This is taken from Monoco Service Tech Tips

Wipe away dirt and debris from the jack ram using a soft lint free cloth. Spray the clean surface with silicone. Avoid other lubricants that may attract dirt and damage seals. Perform this procedure when the jack has been extended for four consecutive days. When staying near ocean areas with heavier salt concentration in the air, spray the jack rams with silicone upon arrival.

 
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