Guys, I live in Switz. have an 06' HDJ100. It has 145k km and generally been great except had some early issues with sensors. That seemed to fix things but the truck seems bouncy again to me, when I hit a speed bump and set suspension to 'comfort' it still seems hard. Plus after you go over the hump there can be a snap sound like it is forcing suspension down. In any event my 1997 80 series with OME is perfect for ride - and 'connected'. But this 'new one' just feels so 'loose'-- often I swear that the front suspension is in 'high mode' as the truck just doesn't feel connected to the road. Sure the PS ain't great-- that gearing they used is so poor when compared with my '97 (but that is another point). So options are to remove and replace and cost about $3k here (parts and labor) but then of course you loose AHC. How long are sensors supposed to last? Mine are 10 years and about 90k miles now...could this be the problem? Welcome any suggestions but I also have a garage that limits my heights-- hence the 2 inch lift and OME I don't think will work. Is there a way to keep it a same height and resolve the problems? This tends to be more a long-distance hauler (filled with big family and stuff) and occasional trailer. Put EBC slotted, vented discs and Yellowstuff pads-- amazing improvement and great on the Autobahn....just in case! Thanks for any ideas,
AHC Suspension question
- Thread starter SwissEd
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I would check the ahc fluid level and for contamination and condition, flush if required, then check the height of vehicle all round and adjust to bring into spec, then adjust torsion bars to correct neutral pressures, might need rear springs or spacers to reduce rear pressure. Then check how many graduations the ahc fluid changes from low to high, if less than 7 then new spheres maybe required. If fluid is low check for leaks.
I would also check all ball joints and sway bar for your noise.
If you search the forum you will find the correct procedures for all the above mentioned in great detail.
I would also check all ball joints and sway bar for your noise.
If you search the forum you will find the correct procedures for all the above mentioned in great detail.
- Thread starter
- #3
Hi,
I checked fluid and it was below MIN. with engine off. Can you confirm if engine should be on or off when checking fluid please. Didn't see any documentation (in French!) on this...ughh. Would sure be nice if my fluid is simply low and that explains, bouncy and why it doesn't want to drop and rise as "normal". It seems to hang and not go up or down. Can I add fluid (what type) myself-- top up, or better to flush system and renew? I am due for service in a couple of weeks. Thanks Ed
I checked fluid and it was below MIN. with engine off. Can you confirm if engine should be on or off when checking fluid please. Didn't see any documentation (in French!) on this...ughh. Would sure be nice if my fluid is simply low and that explains, bouncy and why it doesn't want to drop and rise as "normal". It seems to hang and not go up or down. Can I add fluid (what type) myself-- top up, or better to flush system and renew? I am due for service in a couple of weeks. Thanks Ed
The correct way to check the fluid level is with engine running, drop to L and raise to N - keep engine running so the height accumulator finishes recharging, about 30 seconds, and then read off the level. It is suppose to be between max and min.
The approved fluid is Toyota "suspension fluid, AHC". It comes in 2.5L cans and if you don't know when or if the fluid was last changed then a fluid exchange with associated bleeding should be done, it's a 5 year, 60k mile item. I do mine twice as often.
Bouncy ride could be caused by any number of things ranging from a simple lack of routine maintenance through to the failure of one or more key elements of the system.
AHC maintenance and repair is very searchable here - key phrases like "neutral pressure", "suspension fluid", "damper accumulator" will get you going in the right direction. Have a read of the thread "definitive list of AHC maintenance items".
The approved fluid is Toyota "suspension fluid, AHC". It comes in 2.5L cans and if you don't know when or if the fluid was last changed then a fluid exchange with associated bleeding should be done, it's a 5 year, 60k mile item. I do mine twice as often.
Bouncy ride could be caused by any number of things ranging from a simple lack of routine maintenance through to the failure of one or more key elements of the system.
AHC maintenance and repair is very searchable here - key phrases like "neutral pressure", "suspension fluid", "damper accumulator" will get you going in the right direction. Have a read of the thread "definitive list of AHC maintenance items".
- Thread starter
- #5
Hi,
Just followed your instructions-- truck would not got to LOW -- simply both L and N lights flashed. I then checked fluid while running at approx. 1cm (1/2 inch) BELOW MIN. Does the low fluid level account for why not dropping to L? Thanks
Just in case the obvious has not been stated, for the AHC to function you have to have all of the doors closed. When I first bought my 100, I didn't know this and had to read the manual in the dealership lot to make sure I wasn't buying a truck with broken AHC.
I wouldn't think that low fluid would account for no movement (if anything, going into low would put MORE fluid into the reservoir), but I'm no expert. If air gets in the system, as would happen with VERY low fluid, wouldn't that trigger a sort of limp mode?
It sounds to me like the least you should do is top it off right now before it gets too low and lets air into the system, and then do a proper bleed a refill with new fluid.
Low fluid level doesn't account for not dropping to Low as such. But, low fluid to the point that the pump draws air will cause it to become air locked and it can't produce pressure - end result is the system goes into safe mode and won't function. Is "OFF" flashing? Anything physically obstructing it lowering like inflated coil air bags?
I'd check for AHC DTCs and see where that leads to. I suspect you don't have Techstream so you'll need to manually check for DTCs. I'm not sure if your HDJ has the same diagnostic protocol as US LCs/LXs but for US vehicles you short pins Tc and E1 in Data Link connector DLC1 under you hood, turn the ignition on and read the flashing "OFF" light sequence. Normal, no DTCs, is a constant 0.25s flash frequency. Any faults will come up as a two digit sequence, something like 5 flashes followed by 2 flashes (which would be C1752). To clear codes press the brake pedal 9 times within 3 seconds. Don't forget to remove the shorting wire when done.
I'd check for AHC DTCs and see where that leads to. I suspect you don't have Techstream so you'll need to manually check for DTCs. I'm not sure if your HDJ has the same diagnostic protocol as US LCs/LXs but for US vehicles you short pins Tc and E1 in Data Link connector DLC1 under you hood, turn the ignition on and read the flashing "OFF" light sequence. Normal, no DTCs, is a constant 0.25s flash frequency. Any faults will come up as a two digit sequence, something like 5 flashes followed by 2 flashes (which would be C1752). To clear codes press the brake pedal 9 times within 3 seconds. Don't forget to remove the shorting wire when done.
- Thread starter
- #8
Thanks for input-- that is beyond my skill set. I have a great LC mechanic here and he regularly swaps AHC with fixed suspension (he swapped my shocks on my 80 series with OME-- what a great upgrade. He suggests (if I want to do it) either OME or Terrain Tamer set-up. Any views on those if I decide to say goodbye to AHC? What would that cost in the US-- ball park please. Tkx
For pricing on aftermarket suspension checkout Slee off-road, or any of the supporting vendors here. As far as one system over another and particular configurations? well I'll leave that to someone else.
PS. A truly great LC mechanic would fix your AHC
PS. A truly great LC mechanic would fix your AHC
- Thread starter
- #10
Guys and gals, had AHC checked and they added fluid (assume it was bled). But left and right were off. They adjusted stance and it seemed to work fine for few hundred miles. Just drove from Geneva to Rome (yah, someone has to do it). I noticed along the way when I go over speed bumps (at appropriate speeds) there is little damping irrespective of in comfort or sport mode (and truckis 2006 HDJ100 with 150k km), but the real "shocker" (sorry) is the up weighing of front end when you come off the bump and there is a very harsh near jolt like shock is shooting out. Worse than my FJ40 with Maas Trailmasters and heck that is a SWB. On way here highway had a very rough stretch and pissing down and truck went squirrelly on me at about 90kph--like yes aqua planning with bald tires but tires are fine. Very disconcerting to say the least and dangerous. Heck my '97 FJ80 with OME all around is like a tank and secure. But I feel like the truck is too high and center of gravity is much too high and hence poor tracking. From VT originally and understand snow driving, but this AHC has been a curse. I had an '04 HDJ100 that went thru 6 sensors and Toyota finally gave me a trade in on that truck for my current '06. Gone thru front sensors some years back, but this isn't me having to worry about how she tracks. Very close to pulling trigger on OME swap and be done with it. I watched the Strutmaster video posted on conversion. If you swap out AHC could it theoretically be put back in the future by someone else if I sold the truck ? No plans as she is a keeper with the EBC rotor and yellow stuff pads (great addition BTW). Much appreciate any thoughts. Ed
I wouldn't assume it was bled.
What front and rear heights did the mechanic settle on? I ask because no rake = poor tracking and too high tends to correlate with high neutral pressures.
What front and rear neutral pressures did he set? I ask because these pressures are crucial to good damping.
How many graduations do you read during the L to H AHC check? This is an indicator to damper globe charge which is fundamental to your damping performance.
I doubt anyone would undertake an AHC reinstall unless they were handed all of the take off parts and an assurance it was working 100% prior. Certainly doable if you know what a functioning system looks like, bit of a challenge and steep learning curve for someone with no system experience.
What front and rear heights did the mechanic settle on? I ask because no rake = poor tracking and too high tends to correlate with high neutral pressures.
What front and rear neutral pressures did he set? I ask because these pressures are crucial to good damping.
How many graduations do you read during the L to H AHC check? This is an indicator to damper globe charge which is fundamental to your damping performance.
I doubt anyone would undertake an AHC reinstall unless they were handed all of the take off parts and an assurance it was working 100% prior. Certainly doable if you know what a functioning system looks like, bit of a challenge and steep learning curve for someone with no system experience.
This.
I am curious where you are located? I know CH (parts of it) quite well and I was hard pressed to find a decent mechanic for a 100, let alone a diesel 100. The mechanic may be fine, but 100-specific knowledge was very rare, in my opinion.
PADDO mentions a few things which are really not beyond anyone's skillset. I don't mean to be harsh in any way, but if one can't perform the AHC bleed process (seriously, read the write-up), you need to consider other options. You literally need one spanner or crescent wrench, that's it. The fact that you are smart enough to look this up on 'mud, and ask questions, means you are smart enough to bleed the system. Half an hour max, and you have a garage at your disposal so easy and clean.
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- #13
I am in Geneva area. Garage Bandieri in Bassins (Jura) are excellent. Forget about Emil Frey and the "big ones"-- awful and the prices are stupid. Bandieri even sorted out my smog stuff on my CA FJ40 and for past years doing all well. I drive 45 min just to get there so that should tell you how much I like them. Plus Marc Banideri even speaks English!
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- #14