Hydraulic Supension Problems

[jayfrem]

Hello
My brother 1999 Land Cruiser ( Middle East Spec) has been giving series of problems with its hydraulic suspension.
The truck was bought used and its ride was pretty bumpy/wavy.

Issue was that water was mixed with suspension oil. Had to drain all the oil out and change all 4 hydraulic balls.

We have owned the truck since 2001-2002.

Truck seems to have occasional issues with blown hydraulic balls.
Is this common with these models ? We re changing one at a time (the blown one)

Is it worth the swap to a regulat OME suspension lift ?

Truck is more a daily driver and hardly every sees any dirt. Will the ride be more comfy with OME's ?

I ve tried OME's on Rover and Jeeps and I love the ride.

Thanks
Jay

 

[Texasoil]

The 'hydraulic balls' are called 'accumulators' in the 'trade'. Please go to 'activesuspensionsystems.com' and read all about the AHC system. The accumulators should last several years. OEM replacement units have been reported failing quickly recently (6-18 months)

Water in the system (if to mouch) wil cause excessive wear on the tiny oil pump gears. Otherwise no lasting problems..

It is easy to test the remaining charge (bump absorbtion capacity) of the accumulators on the vehicle. Simply put a wheel up on a 6-8" high curb, then back off quickly to 'drop' it on the pavement. Note how well (or poorly) the 'test bump' is absorbed. A good accumulator will do a real good job, no harsh jolts, vehicle body dropping to a below normal, rebounding to a little above normal, and then settling to normal ride height--all well damped, no bouncing. A bad accumulator give a hard bounce-bounce... as only the tires are absorbing the bump. Repeat the test for the other 3 wheels.

Unless an accumulator fails early, it is normally recommended to replace in axle pairs to keep the 'spring rates' equal to prevent side-to-side pitching going through dips and over speed bumps.

Be sure and change the fluid at least every 30 K miles. The anti-wear additive gets used up . In hot weather the oil film is not thick enough and the tiny pump gears can touch, score, and then self destruct in minutes. You can order just the pump and associated O-ring s and shaft seals from a Dealer for about $350 --instead of >$2200 for the 'assembly. R&R the assembly and then the pump from the assembly is a snap, less than 2 hours hours max 1st time start-to finish and drive off--maybe 15 min longer than R&R just the the assembly.

 

[jayfrem]

The 'hydraulic balls' are called 'accumulators' in the 'trade'. Please go to 'activesuspensionsystems.com' and read all about the AHC system. The accumulators should last several years. OEM replacement units have been reported failing quickly recently (6-18 months)

Water in the system (if to mouch) wil cause excessive wear on the tiny oil pump gears. Otherwise no lasting problems..

It is easy to test the remaining charge (bump absorbtion capacity) of the accumulators on the vehicle. Simply put a wheel up on a 6-8" high curb, then back off quickly to 'drop' it on the pavement. Note how well (or poorly) the 'test bump' is absorbed. A good accumulator will do a real good job, no harsh jolts, vehicle body dropping to a below normal, rebounding to a little above normal, and then settling to normal ride height--all well damped, no bouncing. A bad accumulator give a hard bounce-bounce... as only the tires are absorbing the bump. Repeat the test for the other 3 wheels.

Unless an accumulator fails early, it is normally recommended to replace in axle pairs to keep the 'spring rates' equal to prevent side-to-side pitching going through dips and over speed bumps.

Be sure and change the fluid at least every 30 K miles. The anti-wear additive gets used up . In hot weather the oil film is not thick enough and the tiny pump gears can touch, score, and then self destruct in minutes. You can order just the pump and associated O-ring s and shaft seals from a Dealer for about $350 --instead of >$2200 for the 'assembly. R&R the assembly and then the pump from the assembly is a snap, less than 2 hours hours max 1st time start-to finish and drive off--maybe 15 min longer than R&R just the the assembly.

Is it worth swtiching to a regular suspension system and get it rid of the AHC ?

Thanks
Jay

 

[uHu]

Worth it? is up to you. If you think of long term maintenance costs, then yes it might be worth it to change to ome or other regular suspension. If this is a 1999, and the coil springs have not been changed, then it is probably due for a pair of springs anyhow.
If you keep the AHC, it will probably be enough with a change of "gas-balls" every 200 k km, or maybe a bit less. The pump might also fail.
Start by finding out the cost of 4 springs and 4 shocks.

When changing / cleaning out the polluted AHC fluid, try to empty the shocks as well. The front ones are not to difficult to get to. A normal bleeding will not exchange all the fluid between the shock and the actuator.

 

[jayfrem]

Check out activesuspensions.com. Looks like the accumulators are good quality.
Anyone has tried them ?
I hate to shell more money for non lasting solution.

On the site they mention not to convert the hydro suspension to a regular shock/spring for stability and roll over avoidance. The high end 4x4 such as G Class come in shock and spring.

Let me know your thoughts

Jay

 

[LandCruisers4Life]

Toss all that AHC crap and put on springs.... done.

 

[jayfrem]

Ended up going with a pair of active suspensions systems the ride is much better and it solved the issue.
When the front ones will be worn will upgrade them.

I believe the AHC will still be much more comfy than traditiona/relialble spring and will retain a good resale value.

Jay