Eliminate the air/oil pump

[aw113sgte]

Got my vented pump cap. Removed all air lift and air/oil lines. Also took the safety valves out of the spare tire cylinder as I occasionally have it lock up.
Also checked out the manifold orifices and valves, all in great shape. All filter checked and clear as well.

Having an issue with overflowing the reservoir though I fill it up with the tire up and the cab down. I lift the cab up then let it go down and the reservoir overflows. I do it again and it overflows some more. I do it again and it overflows a third time. It is getting less each time but baffles me why it is at all. I can only figure there's some air in the system that's taking up room and causing the overflow? The other thing I noticed is when I let the cab lower due to gravity, I have to pump it probably 40 times before the cylinder is fully retracted. I could have sworn before it was just a few pumps for that to happen.

 

[GeneralDisorder]

Hhhmmm - have you rebuilt the air-over-hydraulic pump? Sounds like it's aerating the fluid and that's causing the volume to increase and it's efficiency to drop off.

When you say it takes 40 pumps to retract the "cylinder" are you referring to the latch locking pin? If things are working as designed gravity should pull the cab down once it crosses it's balance point and the latch should engage and retract it's locking pin on it's own. It shouldn't require any pumping at all if things are aligned and sealed and there's no air in the system.

 

[aw113sgte]

Hhhmmm - have you rebuilt the air-over-hydraulic pump? Sounds like it's aerating the fluid and that's causing the volume to increase and it's efficiency to drop off.

When you say it takes 40 pumps to retract the "cylinder" are you referring to the latch locking pin? If things are working as designed gravity should pull the cab down once it crosses it's balance point and the latch should engage and retract it's locking pin on it's own. It shouldn't require any pumping at all if things are aligned and sealed and there's no air in the system.

Air over oil is gone, totally removed from the system.

The cab lock engages, but it takes those ~30-40 pumps to draw down the cab cylinder until it hits a "hard stop" where the pump handle doesn't want to move and the cylinder is at it's retracted limit. No sponginess in the pump handle present.

 

[Ronmar]

Got my vented pump cap. Removed all air lift and air/oil lines. Also took the safety valves out of the spare tire cylinder as I occasionally have it lock up.
Also checked out the manifold orifices and valves, all in great shape. All filter checked and clear as well.

Having an issue with overflowing the reservoir though I fill it up with the tire up and the cab down. I lift the cab up then let it go down and the reservoir overflows. I do it again and it overflows some more. I do it again and it overflows a third time. It is getting less each time but baffles me why it is at all. I can only figure there's some air in the system that's taking up room and causing the overflow? The other thing I noticed is when I let the cab lower due to gravity, I have to pump it probably 40 times before the cylinder is fully retracted. I could have sworn before it was just a few pumps for that to happen.

I bet there is enough restriction somewhere, or there is leakage in the valve or pump or even around the rod end of the cylinder and it cannot pull enough vacuum to suck fluid thru the pump into the rod end of the lift cylinder as the cab lowers. Pretty common, hydraulic seals are great at holding pressure, but will leak when a vac is applied instead of pressure. Probably around the pump shaft/piston seal.

When you pump up the cab, it forces fluid back from the rod end as you pump fluid to the base end. If when you lower the cab, the rod end doesnt suck its fluid back, as the base end forces fluid back this will increase the volume in the pump reservoir.

This should stabelize at some point and stop expelling fluid.

You dont want to fully retract the cab cylinder. Ideally you want to let the cab lower into the deflated cab suspension. Then when you inflate the cab suspension the cab attach rod will ride up and down in the long slot. I did a video showing this on utube, usrename Rronmar. There is no float position for the cab lift hydraulics, and if pulled in too far, the cab riding on its suspension will stress the cylinder or mounts...

 

[GeneralDisorder]

There is no need to retract the cylinder. Once the cab latches and the pin retracts you can stop.

 

[aw113sgte]

So with a vented cap on the pump, what's to stop the spare tire cylinder from leaking into the reservoir due to gravity?
Edit: looks like as long as there is no air leak and the reservoir level remains above the return port, it can't.

View attachment 910616

 

[aw113sgte]

I bet there is enough restriction somewhere, or there is leakage in the valve or pump or even around the rod end of the cylinder and it cannot pull enough vacuum to suck fluid thru the pump into the rod end of the lift cylinder as the cab lowers. Pretty common, hydraulic seals are great at holding pressure, but will leak when a vac is applied instead of pressure. Probably around the pump shaft/piston seal.

When you pump up the cab, it forces fluid back from the rod end as you pump fluid to the base end. If when you lower the cab, the rod end doesnt suck its fluid back, as the base end forces fluid back this will increase the volume in the pump reservoir.

This should stabelize at some point and stop expelling fluid.

You dont want to fully retract the cab cylinder. Ideally you want to let the cab lower into the deflated cab suspension. Then when you inflate the cab suspension the cab attach rod will ride up and down in the long slot. I did a video showing this on utube, usrename Rronmar. There is no float position for the cab lift hydraulics, and if pulled in too far, the cab riding on its suspension will stress the cylinder or mounts...

It wouldn't shock me if the pump had some issues. It was clear the shaft was painted over and then the pump used so that paint may be in the seals causing a leak. New pump is on order. Will try to rebuild this one too, looks like there is a retaining circlip or similar on the bottom.

 

[ramdough]

I am on my second stock manual pump and that is leaking too. First one failed quickly.


I bought the one [mention]Ronmar [/mention] used. New pump, new seals, new reservoir, fewer pumps…..

I have yet to install the new one, but I think that is a better way than what you are doing.

Just a suggestion. Get a new pump…..


Sent from my iPhone using Tapatalk

 

[aw113sgte]

I am on my second stock manual pump and that is leaking too. First one failed quickly.


I bought the one [mention]Ronmar [/mention] used. New pump, new seals, new reservoir, fewer pumps…..

I have yet to install the new one, but I think that is a better way than what you are doing.

Just a suggestion. Get a new pump…..


Sent from my iPhone using Tapatalk

Yeah may regret not buying a new one, tune in to find out!

 

[Primussucks]

I've just deleted my air over hydraulic setup. I just went with the power packer hand pump that BrokeOverland spec'd in his video, and what I think some here have done as well.

Plumbed directly to the cab lift cylinder.
Things went pretty smoothly, until I lowered the cab. Flip the lever, couple pumps to get the cab over the balance point, and the cab starts to fall... I can hear the fluid coming back through the pump, and then about 3/4 of the way down, the pump starts pissing fluid out of the back.

Messaged the supplier, and they sent me a new one. They were very quick in responding and replacing.

Installed the new one, and the exact same thing. Lower the cab and fluid start flooding out of the back casing (between the aluminum housing and the plastic reservoir )

I contacted the supplier again, and they said that the pump isn't designed to function like that and requires the factory reservoir to relieve the back pressure.?

From reading here, and watching Chads videos, I don't see anyone else running the stock reservoir with the deleted systems.

My hunch is that the OEM Power Packer doesn't have the problem, and might just be this suppliers 'Power Packer'ish" product?

Anyone else have feedback/experience on this?

 

[Ronmar]

I've just deleted my air over hydraulic setup. I just went with the power packer hand pump that BrokeOverland spec'd in his video, and what I think some here have done as well.

Plumbed directly to the cab lift cylinder.
Things went pretty smoothly, until I lowered the cab. Flip the lever, couple pumps to get the cab over the balance point, and the cab starts to fall... I can hear the fluid coming back through the pump, and then about 3/4 of the way down, the pump starts pissing fluid out of the back.

Messaged the supplier, and they sent me a new one. They were very quick in responding and replacing.

Installed the new one, and the exact same thing. Lower the cab and fluid start flooding out of the back casing (between the aluminum housing and the plastic reservoir )

I contacted the supplier again, and they said that the pump isn't designed to function like that and requires the factory reservoir to relieve the back pressure.?

From reading here, and watching Chads videos, I don't see anyone else running the stock reservoir with the deleted systems.

My hunch is that the OEM Power Packer doesn't have the problem, and might just be this suppliers 'Power Packer'ish" product?

Anyone else have feedback/experience on this?

What is the volume of the pump reservoir

does the pump have an air vent/filler port? That is what PP was getting at, the oe pump does not have a vent either as the plumbing directs fluid to the hand pump up to about 5 psi to keep it full, then sends the rest to the air op reservoir which IS vented. If the new hand pump has a filler plug, open that and try again…

 

[Primussucks]

What is the volume of the pump reservoir

does the pump have an air vent/filler port? That is what PP was getting at, the oe pump does not have a vent either as the plumbing directs fluid to the hand pump up to about 5 psi to keep it full, then sends the rest to the air op reservoir which IS vented. If the new hand pump has a filler plug, open that and try again…

It does indeed have a vented cap.

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[Ronmar]

Well if the vent is clear working , any overflow should be coming from there, not where the pump body meets the reservoir…. Take it completely off and try it…

 

[Primussucks]

Well if the vent is clear working , any overflow should be coming from there, not where the pump body meets the reservoir…. Take it completely off and try it…

Did that last night with the new pump.

I had the cap loosely on. Came out of the back and the cap...

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[Ronmar]

Ok, back to the first question, what is the pump reservoir capacity/volume?

 

[Primussucks]

Ok, back to the first question, what is the pump reservoir capacity/volume?

According to the power packer spec.
35 cubic inch capacity
0.249 cubic inch volume per stroke.

I'm just duplicating Chad..

My suspicion is that what I bought might not be true Power Packer.. might be a quality issue is my hunch.

 

[Ronmar]

2" piston has an area of 3.1416 sq/in. 35cu/in = only 11 inches of cylinder travel.... Now if the rod end has fluid in it returning to the reservoir as the cab raises, that should give you enough fluid to lift the cab.

Depending on the pump internal plumbing and seals, as you lower the cab by gravity, the rod end may not be able to suck fluid from the reservoir, and since the base end holds more fluid than the reservoir you get an overflow...

You may also be pumping some air along to the cylinder near the end, which would also cause issues, as the base end on a vertical cylinder will send the fluid back first causing an overflow...

Hydraulic seals are very good at holding pressure in one direction, and notoriously bad at withstanding pressure in the opposite direction when a vacuum is applied. I suspect you will find it is either sucking in air around the control valve or the hydraulic rod end cylinder instead of sucking oil. This will especially be true if you are using the control to throttle the lowering speed.

Unscrew the vent and put in a hose barb and run it into a secondary reservoir to increase your volume to something greater than that used by the cylinder to lift the cab. Or replace the pump with something with a larger reservoir.

I used a prince wolverine 1.5 cu/inch pump with 40 or 60 oz reservoir. This has the advantage of being able to lift the cab much faster than the .25 cu/in. ~28 pump strokes as opposed to the 168 that the stock .25cu/in requires. Vid of it over on Youtube, username Rronmar

 

[Primussucks]

of 3.1416 sq/in. 35cu/in = only 11 inches of cylinder travel.... Now if the rod end has fluid in it returning to the reservoir as the cab raises, that should give you enough fluid to lift the cab.

Depending on the pump internal plumbing and seals, as you lower the cab by gravity, the rod end may not be able to suck fluid from the reservoir, and since the base end holds more fluid than the reservoir you get an overflow

Hmm.. got me thinking a little bit.. I could use the spot where the manifold was previously housed. put a reservoir in its place and plumb into the pump. I'm going to look at the prince wolverine pump you have as well.

Either way, i'm curious of anyone that used the same setup here has had similar issues?

 

[Reworked LMTV]

Hmm.. got me thinking a little bit.. I could use the spot where the manifold was previously housed. put a reservoir in its place and plumb into the pump. I'm going to look at the prince wolverine pump you have as well.

Either way, i'm curious of anyone that used the same setup here has had similar issues?

I went pure hydraulic about 3 years ago. No issues. I carry the hand pump, but it is not connected. I use a Haldex electric hydraulic pump. Have extra one for back up AND can connect the manual pump if all else fails. Carry extra hydraulic fluid.

 

[aw113sgte]

With my manual setup, I removed the flow restriction orifice on the return side of the cab lift cylinder (non pressure side so safety spring balls still in place), that seems to have cured the issue with the overflowing of the reservoir as the cylinder can suck the fluid in easier.
Before I did that, I just pumped while the cab was going down and that sent fluid to the cylinder return side and prevented overflow.
The reservoir has ample volume to raise the cab and lower the tire at the same time.
I have a larger reservoir but it won't fit in the stock location. Probably won't end up using it.