Coach "settling" after auto leveling and putting bed down??

[lesliedepol]

Has anyone heard "settling noises" after leveling the coach with the hydraulic system and lowering the Murphy Bed? These noises come and go and appear to be coming from the front driver side arm. Also hear a bit when walking around the bed. Don't hear at all when the bed is put away.

 

[AbdRahim]

What leveling system do you have. I used to hear my Equalizer jacks popping regularly. Adding Cat Hydraulic Oil Additive seemed tofix the problem. You can do an internet search on this.

 

[lesliedepol]

We have Equalizer Systems. Thank you for this tip, we'll look into it.

 

[Wemustrv]

What leveling system do you have. I used to hear my Equalizer jacks popping regularly. Adding Cat Hydraulic Oil Additive seemed tofix the problem. You can do an internet search on this.

I don't have any popping just curious what would cause it. Air bubbles in fluid?

 

[AbdRahim]

I don't have any popping just curious what would cause it. Air bubbles in fluid?

Not sure. The Cat fluid is anti-striction. I am not knowledgeable on the technical aspects.

 

[Joe Dutchstar]

Grok provided an interesting summary of CAT additive and its use. Apparently Lippert also recommends this additive.

“Caterpillar (CAT) Hydraulic Fluid Additives


Caterpillar (CAT) hydraulic systems, commonly found in heavy equipment like excavators, loaders, and tractors, rely on specialized fluids and additives to ensure longevity, reduce wear, and maintain performance. CAT does not typically recommend standalone “additives” for routine use in their modern hydraulic oils, as their flagship products like Cat HYDO Advanced already incorporate a comprehensive, balanced additive package. However, there is a specific CAT-approved additive for targeted applications, such as reducing noise and friction in certain hydraulic setups (e.g., RV leveling systems using Lippert Components). Below, I’ll break down the key options, recommendations, and usage.


1. Primary CAT Hydraulic Fluid: HYDO Advanced (with Built-in Additives)

• Description: This is CAT’s go-to hydraulic oil for most machines. It’s formulated with premium base oils and a proprietary additive system, eliminating the need for separate additives in standard applications. Key additives include:
  • Anti-wear agents: Protect pumps and components from metal-to-metal contact.
  • Rust and corrosion inhibitors: Prevent damage in humid or corrosive environments.
  • Detergents and dispersants: Keep systems clean by suspending contaminants.
  • Defoamers: Reduce foam to maintain efficient power transfer.
  • Emulsifiers: Allow controlled water dispersion without harming seals.
• Benefits:
  • Extended drain intervals: Up to 6,000 hours (vs. 2,000 hours for many commercial oils) when monitored via CAT’s S·O·S Services oil analysis.
  • Superior performance in extreme temperatures and high-pressure systems.
  • Tested specifically for CAT equipment to meet or exceed ISO and ASTM standards.
• Variants:
  • HYDO Advanced 10 (SAE 10W): For general use; available in 5-gallon pails (e.g., part #309-6931).
  • Bio HYDO Advanced (HEES): Biodegradable, non-toxic option for environmentally sensitive areas; uses synthetic base oils with premium additives (e.g., part #339-3249).
• Where to Buy: CAT dealers, Amazon, or parts.cat.com. Avoid industrial hydraulic oils, as they often lack these critical additives and can shorten component life.

2. Dedicated CAT Hydraulic Oil Additive: Part #1U-9891

• Description: This is a low-friction, anti-stiction additive (32 fl oz quart) designed to mix with existing hydraulic fluid. It’s not a full replacement fluid but a supplement to reduce hydraulic noise, popping, and seal friction—common in older systems or non-CAT applications like RV hydraulic jacks.
• Key Components: Primarily anti-stiction agents and friction modifiers; compatible with ATF (e.g., Dexron III or Mercon V) or CAT HYDO.
• Usage Instructions (based on Lippert/CAT guidelines for noisy systems):
  1. Retract all jacks/slides and remove 1 quart of fluid from the reservoir.
  2. Add ½ quart of 1U-9891 and extend components fully.
  3. Add the remaining ½ quart and retract.
  4. Cycle the system 2–3 times to mix thoroughly.
  5. Dosage: 1 quart total per system (do not exceed; over-addition can thicken fluid).
  6. Compatibility: Works with CAT HYDO or automotive ATF; users report it quiets “popping” sounds dramatically.
• Benefits:
  1. Reduces seal groan and noise without needing full fluid replacement.
  2. Improves smoothness in low-volume systems.
• Warnings: Not for all CAT machines—consult SEBU6250 (CAT Fluids Recommendations) or your manual. Dispose of drained fluid per local regulations (e.g., as hazardous waste).
• Where to Buy: CAT parts stores (parts.cat.com), eBay (~$25/quart), or dealers like Peterson Cat. Search for “1U-9891 Hydraulic Oil Additive.”

General CAT Recommendations

• Avoid Aftermarket Additives: “Snake oil” stop-leak or generic additives can swell seals unevenly, cause clogs, or void warranties. Stick to CAT products for optimal results.
• Maintenance Tips:
  • Change fluid every 2,000–6,000 hours based on S·O·S analysis.
  • Check for contamination (e.g., water or dirt) and replace filters regularly.
  • In hot climates, use HYDO Advanced for better thermal stability.
• Alternatives for Specific Needs:
  • For fork oil-based systems: Torco RFF Grade 15 or Maxima Fork Oil Grade 15 (drain 2 quarts before adding).
  • For biodegradable needs: Bio HYDO Advanced.”

 

[lesliedepol]

Grok provided an interesting summary of CAT additive and its use. Apparently Lippert also recommends this additive.

“Caterpillar (CAT) Hydraulic Fluid Additives


Caterpillar (CAT) hydraulic systems, commonly found in heavy equipment like excavators, loaders, and tractors, rely on specialized fluids and additives to ensure longevity, reduce wear, and maintain performance. CAT does not typically recommend standalone “additives” for routine use in their modern hydraulic oils, as their flagship products like Cat HYDO Advanced already incorporate a comprehensive, balanced additive package. However, there is a specific CAT-approved additive for targeted applications, such as reducing noise and friction in certain hydraulic setups (e.g., RV leveling systems using Lippert Components). Below, I’ll break down the key options, recommendations, and usage.


1. Primary CAT Hydraulic Fluid: HYDO Advanced (with Built-in Additives)

• Description: This is CAT’s go-to hydraulic oil for most machines. It’s formulated with premium base oils and a proprietary additive system, eliminating the need for separate additives in standard applications. Key additives include:
  • Anti-wear agents: Protect pumps and components from metal-to-metal contact.
  • Rust and corrosion inhibitors: Prevent damage in humid or corrosive environments.
  • Detergents and dispersants: Keep systems clean by suspending contaminants.
  • Defoamers: Reduce foam to maintain efficient power transfer.
  • Emulsifiers: Allow controlled water dispersion without harming seals.
• Benefits:
  • Extended drain intervals: Up to 6,000 hours (vs. 2,000 hours for many commercial oils) when monitored via CAT’s S·O·S Services oil analysis.
  • Superior performance in extreme temperatures and high-pressure systems.
  • Tested specifically for CAT equipment to meet or exceed ISO and ASTM standards.
• Variants:
  • HYDO Advanced 10 (SAE 10W): For general use; available in 5-gallon pails (e.g., part #309-6931).
  • Bio HYDO Advanced (HEES): Biodegradable, non-toxic option for environmentally sensitive areas; uses synthetic base oils with premium additives (e.g., part #339-3249).
• Where to Buy: CAT dealers, Amazon, or parts.cat.com. Avoid industrial hydraulic oils, as they often lack these critical additives and can shorten component life.

2. Dedicated CAT Hydraulic Oil Additive: Part #1U-9891

• Description: This is a low-friction, anti-stiction additive (32 fl oz quart) designed to mix with existing hydraulic fluid. It’s not a full replacement fluid but a supplement to reduce hydraulic noise, popping, and seal friction—common in older systems or non-CAT applications like RV hydraulic jacks.
• Key Components: Primarily anti-stiction agents and friction modifiers; compatible with ATF (e.g., Dexron III or Mercon V) or CAT HYDO.
• Usage Instructions (based on Lippert/CAT guidelines for noisy systems):
  1. Retract all jacks/slides and remove 1 quart of fluid from the reservoir.
  2. Add ½ quart of 1U-9891 and extend components fully.
  3. Add the remaining ½ quart and retract.
  4. Cycle the system 2–3 times to mix thoroughly.
  5. Dosage: 1 quart total per system (do not exceed; over-addition can thicken fluid).
  6. Compatibility: Works with CAT HYDO or automotive ATF; users report it quiets “popping” sounds dramatically.
• Benefits:
  1. Reduces seal groan and noise without needing full fluid replacement.
  2. Improves smoothness in low-volume systems.
• Warnings: Not for all CAT machines—consult SEBU6250 (CAT Fluids Recommendations) or your manual. Dispose of drained fluid per local regulations (e.g., as hazardous waste).
• Where to Buy: CAT parts stores (parts.cat.com), eBay (~$25/quart), or dealers like Peterson Cat. Search for “1U-9891 Hydraulic Oil Additive.”

General CAT Recommendations

• Avoid Aftermarket Additives: “Snake oil” stop-leak or generic additives can swell seals unevenly, cause clogs, or void warranties. Stick to CAT products for optimal results.
• Maintenance Tips:
  • Change fluid every 2,000–6,000 hours based on S·O·S analysis.
  • Check for contamination (e.g., water or dirt) and replace filters regularly.
  • In hot climates, use HYDO Advanced for better thermal stability.
• Alternatives for Specific Needs:
  • For fork oil-based systems: Torco RFF Grade 15 or Maxima Fork Oil Grade 15 (drain 2 quarts before adding).
  • For biodegradable needs: Bio HYDO Advanced.”

Really helpful details! Will settle into this and report back...

 

[eZAK]

I heard just the opposite from Lippert. They told me to not use any additives, and, their systems are filled automatic transmission fluid.
Also, if an owner needs to top off their reservoir they can use Dextron III or Mercon IV.
(We) Lippert should be made aware of all other problems.

 

[Vint]

Check out the iRV2 Forum; there is a lot of conversation there regarding popping sounds coming from their levelers, including Lippert systems. Back when I had a Georgetown gas rig, there were also healthy conversations on the Forest River Forum on the same subject, especially regarding Lippert-based levelers.