Slide doesn't stay tight to frame when driving the MH

[bamaboy473]

We are new to MHs and have a 36' Valencia, Cummins, Allison, Freightliner, 2 slides.

I've noticed that the bottom of the large slide tends to wander up to 1.5" away from the coach after several hundred miles. The locks keep the top of the slide flush to the coach (luckily). Hitting Retract brings it back in

Is this kind of normal? If not, what's the plan for diagnosis?

[wa8yxm]

Question: Slides come in 3 flavors that I know of and I would like to think there is a 4th

Rack and Pinion, such as my Power Gear Slide,,, How to Identify: When slide is out if you look at the under side there are 2 or 3 LONG toothed rails (2 in my case) These are the racks. My comments below apply to this system

Hydraulic: You should see the pistons and hoses. and hear the pump run when you put 'em in and out.

Cable cars When extended you will see 2 cables on the Foreward and 2 more on the rearward side of the slide.

Theory has it you could have a screw drive but I've never seen one.

Now: on the Rack and Pinion.. With the slide out you should be able to locate the motor and transmission.. on one end of the motor is a rubber like cap, and under that cap is a lever.. This lever is the manual brake release.. Odds are it is in the released position.... Try moving it to the other position (then make sure the slide still works) If this solves the problem, good.. If not, bad brakes. (The brake assembly is part of the motor assembly and .. I am afraid costly).

[dougrainer]

jdevans22 wrote:
The eletcric motor may have leaver on it to lock the motor. Also our coach has bars that are put in to keep the sldie from moving.

No electric motor. This is a Hydraulic slide system. Doug

[jdevans22]

The eletcric motor may have leaver on it to lock the motor. Also our coach has bars that are put in to keep the sldie from moving.

[alkillion]

Tried the board trick with my Adventurer with HWH slides and levelers. Bent the slide frame really bad. Call HWH and get their help. In short, their system maintains positive pressure in both directions on the slide. When you have a bad seal on the inbound solenoid the 'hold in' pressure bleeds off, so the outbound pressure pushes the slide out. The temp fix is to run the slide in, brace with boards, then release the pressure on both the inbound and outbound sides by turning the bleed screws on both the solenoids. The trick is to figure out which two solenoids to use. Fix is replacing solenoids at about $100 each.
Good Luck

[dougrainer]

1. HWH NOT HTH:B
2. Air in the bags or empty should NOT affect a HWH slide mechanism operation.
3. The HWH systems self purge, you just operate the jacks and slide room/s 3 or 4 times to purge any possible air
4. DO NOT INSTALL any other blocks to hold the room in. There is static pressure on a HWH slide cylinder and that is what is pushing the bottom of the room out. Not a big deal when you have top slide locks, but a big deal if you try to brace the bottom. You risk damaging the wall and inside fascia from the pressure pushing out the room
5. The MOST an HWH slide will extend with this type problem is 3 to 4 inches MAX, just keep retracting when it does this until you fix it.
6. The FIX is simple. IF you inspect the system and see no obvious external oil leaks the Extend and Retract solenoids for that slide need replaced. BUT, do this before you replace them. RETRACT the room and then open each solenoid (retract and extend for that slide) manually and that will purge any possible debris in the solenoid needle valves. The room will extend slightly when you do this (about 2 to 3 inches and no more. Retract and open the valves again. Then close the valves and retract and see if it stays retracted, IF NOT, then replace the 2 solenoids. The solenoids are leaking internally and that causes the room to slightly extend. Doug

[CA_Traveler]

Maybe drive it with slightly shorter boards. Contact HTH and see if they have additional information.

[bamaboy473]

It says that coach air pressure needs to be up to snuff. Ride height isn't mentioned, and I can extend/retract the slides either sitting on all 6 or on the jacks.
I guess the way to test the low fluid possibility is to add fluid to the reservoir and take the coach a couple hundred miles up the road without having the support bracket installed.

No procedure that I found about purging air, but looks like I can add over a pint of ATF and not come close to over-flowing. No "ADD" or "FULL" marks on the tank...

[CA_Traveler]

bamaboy473 wrote:
Thanks, guys. The owner's manual provided info that the slide is hydraulic, and operated by the same pump that levels the MH (HTH brand).

(note: I also learned that if my coach sits for a week, then enough air drains that the slide won't extend all the way; giving rise to great fear of having to ask an RV mechanic to make a house call) Running the engine allowed air to build to 125 and the slide engaged properly.

I'm going to fill the reservoir and mark the fill line, then see how it is after another trip we're taking this coming weekend. In the meantime, a couple of scrap 4x4s will now support the slide bottom...just in case.

Are they saying that the rig needs to be aired up and at ride height in order for the slides to seat properly?

Hydraulics are a closed system that work under high pressure. But low on fluid could be a problem. Does HTH provide a procedure to purge any air in the hydraulics and to make sure the oil level is correct?

My Lipper says to cycle the slides several times to purge any air which I had to do when I replaced the pump.

[bamaboy473]

vanzuilekom wrote:
Let me know the year and if the slide mechanics are Power Gear.
If it is then I will send you the fix process as I had this happen as well. Never since the simple fix 2 years ago.

Thanks, guys. The owner's manual provided info that the slide is hydraulic, and operated by the same pump that levels the MH (HTH brand).

(note: I also learned that if my coach sits for a week, then enough air drains that the slide won't extend all the way; giving rise to great fear of having to ask an RV mechanic to make a house call) Running the engine allowed air to build to 125 and the slide engaged properly.

I'm going to fill the reservoir and mark the fill line, then see how it is after another trip we're taking this coming weekend. In the meantime, a couple of scrap 4x4s will now support the slide bottom...just in case.

[dieharder]

bamaboy473 wrote:
lol, you lost me on that one. How does that board keep the bottom of the slide from working "out" of the chassis?

On the inside of the coach, with the slide in, there is a lip around the slide that makes a seal when the slide is out. On the bottom, cut a piece of 2X4 the length between that lip and the wall. Wedge it in and the slide can't go out while on the road. Have to take it out before sliding it out when you need to.

[CA_Traveler]

bamaboy473 wrote:


Is this kind of normal?

No, not normal or acceptable. Could stress the slide, leak if it rained, etc.

If motor driven then it should be held by the motor or brake. If hydraulic then you might have a valve leak.

[sch911]

They do make slide locks:



Slide Locks

[vanzuilekom]

Let me know the year and if the slide mechanics are Power Gear.
If it is then I will send you the fix process as I had this happen as well. Never since the simple fix 2 years ago.

[dougrainer]

No, it is not normal. Is this a Electric motor slide or a Hydraulic slide? Doug