Barry Bowen
Gold Member
I was told today, that if you replace bias rear tractor tires with radials, that you should not put the fluid back in them. Is this true any one, and why any one?
Fluid in Radial Tractor Tires
- Thread starter Barry Bowen
- Start date
banjodunn
Veteran Member
G'day Barry the rason they say not to fill radials with fluid is in case of a fracture on the inside wall water will rust the steel cords, however we have been fitting tubes and filling with water over here for years without any problems the tubes give you that safety barrier between the tyre and the fluid.
Jon
Jon
Renze
Elite Member
Sounds B.S. to me. Both tires are made of rubber, so both are waterproof.
There is no technical reason against filling radials either, as it is common practice.
Iangb
New member
I run Michelin radials on my tractor.
They recommend wheel weights as ballast because:
Liquid ballast reduces the tyre footprint because it acts on the bottom of the tyre rather than the axle (larger footprint is one of the main advantages of radial tyres). The smaller footprint reduces traction and increases soil compaction.
Liquid ballast make tyres are more vulnerable to impact damage.
Liquid ballast reduces ride comfort and increases tendency to 'power hop'.
That said, liquid ballast is better than no ballast at all when extra weight is needed.
They recommend wheel weights as ballast because:
Liquid ballast reduces the tyre footprint because it acts on the bottom of the tyre rather than the axle (larger footprint is one of the main advantages of radial tyres). The smaller footprint reduces traction and increases soil compaction.
Liquid ballast make tyres are more vulnerable to impact damage.
Liquid ballast reduces ride comfort and increases tendency to 'power hop'.
That said, liquid ballast is better than no ballast at all when extra weight is needed.
OP
Barry Bowen
Gold Member
Thanks for the imputs folks. I have been looking at as much on this subject as I can find on the net, and I noticed something about all the traction tests I saw performed. They were all on flat ground. This is something I do not have any over! The more tire people I talk to the concenus is that radial should either be empty or no more than 40-50% fluid capacity. Since an 18.4-38 holds around 110 gallons that should be around 50 gallons or so. Think my solution will be to put about that much in the tires and hang around 300 pounds of iron on the axles. This will get me to aboutn 800 pounds ballast verus the 1200 per tire with the calcium in bias tires. It also appears that your air needs to go up a little with radials. Seems the point there is 18-22 vs the 16-18 on bias. It certainly has been a education trying to figure out the change, thanks for the help gentlemen.
slowzuki
Elite Member
- Joined
- Sep 19, 2003
- Messages
- 4,155
- Location
- New Brunswick, Canada
- Tractor
- Kubota L5030 HSTC, MF 5455, Kubota M120, Allis Chalmers 7010
If using calcium without tubes, you have to go higher than the rim or it will rust out. A radial is expensive to replace, I'd run tubes if possible.
That said, my Michellin radials are filled and it sure looks like there is no tube. If you are running low pressures like you normally do with radials there is increased risk of shearing the tube fill stem too.
The previous owner ran the fronts too low and cracked the fronts sidewalls so bad they wouldn't hold air. The replacements are looking in rough shape already.
That said, my Michellin radials are filled and it sure looks like there is no tube. If you are running low pressures like you normally do with radials there is increased risk of shearing the tube fill stem too.
The previous owner ran the fronts too low and cracked the fronts sidewalls so bad they wouldn't hold air. The replacements are looking in rough shape already.
Iangb
New member
Radials run at reduced pressure compared to bias tyres.
Look at running 12-16psi. Radial tyres should show a pronounced sidewall bulge under load. This increases the tyres footprint.
My friend with a small farm no longer fills the tractor tires with fluid. I have read several OEM's and tire mfg who no longer recommend this for the reasons Iangb stated. I can tell you my own experience I much prefer the fully air filled tire. It just rides so much better and seems to pull better even though we didn't weight the tractor down to the same point the tractor should have been with filled tires.
I know there are some guys out there who will say fluid is better.
Here is my example of why it isn't recommended. If you fill a tire to lets say 75% full, that leaves 25% air. As you load the rear of the tractor pulling a load like a plow this will tend to make the tire squat. With a 75% filled tire the air pressure will rise much faster being that it only has 25% of the space. This will prevent the tire from squating as much as an air filled tire. From what I have read this is one cause of "power hop" where the tire will compress, then "spring back". You get the same effect going over a log or rock with the tractor. I have also read with tractors today being faster roading they don't recommend it.
From what I have read the power hop is only an issue in 100 Hp and over tractors. The fluid fill seems to apply to all size tractors
I know there are some guys out there who will say fluid is better.
Here is my example of why it isn't recommended. If you fill a tire to lets say 75% full, that leaves 25% air. As you load the rear of the tractor pulling a load like a plow this will tend to make the tire squat. With a 75% filled tire the air pressure will rise much faster being that it only has 25% of the space. This will prevent the tire from squating as much as an air filled tire. From what I have read this is one cause of "power hop" where the tire will compress, then "spring back". You get the same effect going over a log or rock with the tractor. I have also read with tractors today being faster roading they don't recommend it.
From what I have read the power hop is only an issue in 100 Hp and over tractors. The fluid fill seems to apply to all size tractors
art
Super Member
Power hop, is caused by NOT having the correct air pressure in tires!
We balance that out with air pressure loaded tires or not! The reasson that it is hopping is do to gear wind up from not having a good balance between the front and rear drive.
Normally we can do it with the fronts but if someone has made to much of an error with the rear air pressure we correct that first.
For what we have seen the cast weight is worth more in lbs then liquid!
The loss of the flexibility of the tire caused by the fluid in the tires is actually a handy cap to the tire!
We balance that out with air pressure loaded tires or not! The reasson that it is hopping is do to gear wind up from not having a good balance between the front and rear drive.
Normally we can do it with the fronts but if someone has made to much of an error with the rear air pressure we correct that first.
For what we have seen the cast weight is worth more in lbs then liquid!
The loss of the flexibility of the tire caused by the fluid in the tires is actually a handy cap to the tire!
Power hop can occur in 2wd drive tractors as well as 4wd. You don't get the bouncing back and forth like a 4wd, more of an up and down. Below are the important parts of the pages along with links to anyone who would like to read more. Deere and Michelin both give liquid filled tires and issues with power hop. Deere only recommend at most 40% fill on tires.
http://asae.frymulti.com/data/pdf/6/phit2008/LecSeries32_fry.pdf
JCW Power hop was apparently first observed soon
after 4WD tractors began to appear in North America in the
1950s. The earliest incidence of power hop reported by
John Deere engineers occurred in 1958 during tests of a
prototype of the model 8010 4WD tractor (Figure 1), the
first 4WD tractor designed by John Deere. The test engineers
had not seen this behavior before and did not know
what to call it. In their test reports, they referred to it as
Bunny hop, the name of a dance that was popular with
teenagers at the time. Later, power hop was also observed
when MFWD tractors were introduced in the 1970s. Power
hop can occur on MFWD tractors equipped with front suspension
systems, but is far less likely than with unsuspended
tractors. Although power hop can occur with 2WD
tractors, it is extremely rare in field applications. It has
been observed at very high pull levels in tests of 2WD tractors
on soil and on concrete. It is likely to be the instability
sometimes cited in Nebraska tractor test reports as �ull in
nth gear was limited by tractor stability. Power hop also
can occur in 4WD trucks, 4WD automobiles, and certain
types of multi-axle drive military vehicles all operating in
off-road high draft conditions.
__________________________________________________________________________
Michelin AG - Control Power Hop
Power hop is a type of pitch/bounce movement occurring on 4WD and MFWA tractors during field operations. As power hop begins, the tractor undergoes combined pitch and bounce motions that gradually increase to the point where the operator will have difficulty staying in the seat and maintaining control of the tractor.
When does Power hop occur ?
Power hop can affect any make or model of 4WD or MFWA tractor. It occurs under medium to heavy drawbar load with towed implements. Typically the ground is dry, with loose soil on top. Power hop tendency and intensity increase as power input increases. Power hop can occur with bias or radial tires, but maybe more prevalent with radial tires because of the higher level of traction developed.
But, power hop can be controlled!
What factors can influence Power hop? But, power hop can be controlled!
Not enough overall tractor weight for the horsepower
Incorrect weight distribution between front and rear axles
Incorrect tire pressures
Improper drawbar height for the implement
Installation of tires smaller than recommended by the tractor manufacturer
Engine horsepower improvements without additional ballast
Following these rules To Obtain Optimum Tire Performance Will Solve
Ensure the tractor has a sufficient weight to horsepower ratio for the field operating speed. Add cast ballast as necessary to achieve the required weight. Michelin does not recommend the use of liquid ballast in the tires as this will change the stiffness of the tires and may make power hop difficult or impossible to control.*
__________________________________________________________________________
Performance, controlling power hop
Power hop causes tractor bouncing and/or jumping at field working speeds under 16 km/h (10 mph). This condition occurs when an MFWD-equipped tractor is pulling a drawn implement at medium to high draft loads in loose, dry soil on top of a firm base. The condition may occur while climbing hills. Tractors should first be properly ballasted according the total weight and weight split guidelines for the application.
As a result of power hop, the tractor cannot maintain pull efficiency from either loss of traction, a rough ride, or both. Make adjustments only after ensuring the guidelines for optimum performance with towed implements have been followed. These guidelines are:
Front axle weight split is within guidelines for front axle type (2WD, MFWD, ILS? and implement load (light, medium, or heavy).
If liquid ballast is used in the rear tires, it should not exceed 40 percent fill (4 o clock valve stem position)
Front and rear inflation pressures are set correctly based on static axle loads
http://asae.frymulti.com/data/pdf/6/phit2008/LecSeries32_fry.pdf
JCW Power hop was apparently first observed soon
after 4WD tractors began to appear in North America in the
1950s. The earliest incidence of power hop reported by
John Deere engineers occurred in 1958 during tests of a
prototype of the model 8010 4WD tractor (Figure 1), the
first 4WD tractor designed by John Deere. The test engineers
had not seen this behavior before and did not know
what to call it. In their test reports, they referred to it as
Bunny hop, the name of a dance that was popular with
teenagers at the time. Later, power hop was also observed
when MFWD tractors were introduced in the 1970s. Power
hop can occur on MFWD tractors equipped with front suspension
systems, but is far less likely than with unsuspended
tractors. Although power hop can occur with 2WD
tractors, it is extremely rare in field applications. It has
been observed at very high pull levels in tests of 2WD tractors
on soil and on concrete. It is likely to be the instability
sometimes cited in Nebraska tractor test reports as �ull in
nth gear was limited by tractor stability. Power hop also
can occur in 4WD trucks, 4WD automobiles, and certain
types of multi-axle drive military vehicles all operating in
off-road high draft conditions.
__________________________________________________________________________
Michelin AG - Control Power Hop
Power hop is a type of pitch/bounce movement occurring on 4WD and MFWA tractors during field operations. As power hop begins, the tractor undergoes combined pitch and bounce motions that gradually increase to the point where the operator will have difficulty staying in the seat and maintaining control of the tractor.
When does Power hop occur ?
Power hop can affect any make or model of 4WD or MFWA tractor. It occurs under medium to heavy drawbar load with towed implements. Typically the ground is dry, with loose soil on top. Power hop tendency and intensity increase as power input increases. Power hop can occur with bias or radial tires, but maybe more prevalent with radial tires because of the higher level of traction developed.
But, power hop can be controlled!
What factors can influence Power hop? But, power hop can be controlled!
Not enough overall tractor weight for the horsepower
Incorrect weight distribution between front and rear axles
Incorrect tire pressures
Improper drawbar height for the implement
Installation of tires smaller than recommended by the tractor manufacturer
Engine horsepower improvements without additional ballast
Following these rules To Obtain Optimum Tire Performance Will Solve
Ensure the tractor has a sufficient weight to horsepower ratio for the field operating speed. Add cast ballast as necessary to achieve the required weight. Michelin does not recommend the use of liquid ballast in the tires as this will change the stiffness of the tires and may make power hop difficult or impossible to control.*
__________________________________________________________________________
Performance, controlling power hop
Power hop causes tractor bouncing and/or jumping at field working speeds under 16 km/h (10 mph). This condition occurs when an MFWD-equipped tractor is pulling a drawn implement at medium to high draft loads in loose, dry soil on top of a firm base. The condition may occur while climbing hills. Tractors should first be properly ballasted according the total weight and weight split guidelines for the application.
As a result of power hop, the tractor cannot maintain pull efficiency from either loss of traction, a rough ride, or both. Make adjustments only after ensuring the guidelines for optimum performance with towed implements have been followed. These guidelines are:
Front axle weight split is within guidelines for front axle type (2WD, MFWD, ILS? and implement load (light, medium, or heavy).
If liquid ballast is used in the rear tires, it should not exceed 40 percent fill (4 o clock valve stem position)
Front and rear inflation pressures are set correctly based on static axle loads