Texasoil

Hey Rob, Just FYI..... I just went through my THIRD set of B&B Accumulators (all of which have failed within 3 months of light usage) and now Keith will not replace this faulty set. Hindsight being 20/20 I definitely would have either switched to a more basic suspension setup of gone with OEM parts seeing as I would have saved some money now. I'd love to hear how quickly everyone else's has gone out. A

you can and should buy ONLY the actual 'pump sub-assembly' and the 2 O-ring seals should cost $350 +/- send me an email if you have difficulty and I can probably buy it and resale to you

Just got the news from Lexus dealer that the bouncy ride in the LX470 was caused by contamination in the hydraulic fluid in the automatic height control. The contamination ruined the seals in the accumulators and hydraulic oil went into the struts where the nitrogen gas is supposed to be. Dealer recommendation: New accumulators $2,200, hydraulic fluid $100 and labor about $900. Total cost $3,200. This same dealer flushed the hydraulic system 2 years ago. He said the oil that they flushed out must have been contaminated. The did not offer to do an oil test to see if the current oil was contaminated. Our LX470 is a '99 with 120,000 miles on it. This solution is too pricey. I think we will replace the suspension with a non automatic height control suspension for a toyota land cruiser. I am guessing the cost will be around $1,600 to $2,000. Hope that helps. go to my site (activesuspensionsystems.com) and read all about the AHC system and repair alternatives before junking the AHC system. If you DO decide to remove it, I would like to acquire all the parts (pump, height sensors control valves, struts--all for my research.

Shop around. You might want to conside a warranty that "Covers Everything -except....." You have much better coverage and know exactly what your repair exposure is limited to. There are LOTS of things not covered by warranties that list parts. LOTS of 'failures' can be 'caused by an uncovered part'

you need to pull the error code(s) that have caused the system to shut down (or have them read by the Dealer for you) Many things can cause the fault. I have been hearing quite a few problems with the pressure sensor failing. THat will cause the pump to shut off and the system to stop. Dealers seem to think replacing the pump assembly (for $3-4,000) is the first thing to do in this case. WRONG. Several things will cause the pump to shut off or stop after a few seconds. Try putting 12 v directly to the pump and make sure it is not a dead motor. Relays do fail. Pressure sensors do fail. Connections do fail. Pumps SELDOM fail. Go to my web site (activesuspensionsystems.com) and read all about the AHC system

In all probability the strut accumulators are shot. A simple test is easy,fast, and reliable. Drive one wheel at a time up on a 4-6" high curb at a sharp angle (90 deg if possible) and then back off quck enough to 'drop' the wheel on the pavement. A good strut accumulator will allow the bump to be smoothly absorbed without any harsh jolts or bouncing around. A flat accumulator will result in a hard bounce-bounce-bounce as only the tires are flexing to absorb anything. . Repeat for the other 3 wheels. The "shocks' on the AHC suspension are really very simple hydraulic jacks. There is NO reason to ever replace the 'shocks' if they are not leaking a lot and the mounting bushings are intact. Nothing inside to wear out. Please follow the earlier advice, go to my web site and read about the system

You obviously have some very crappy tires on your vehicle. Why do you torture yourself that way? Ditch the tires for some decent ones. I refuse to accept any tire that needs more than 2 oz of weight or does not run true when on the balance machine.

pay for a real good pre-purchase inspection from the LEXUS dealer. They KNOW what to look for.

By Federal LAW, all gasoline engine vehicles sold in the US MUST be capable of operating without damage on 87 AKI gasoline. Higher compression engines like the LX and other cars that 'require premium' are equipped with sensors that detect fuel knocking (detonation) and generally !Removed! the ignition timing enough to stop the knocking (and likely engine damage). However, the engine will not deliver its rated power or fuel economy if it is more than lightly loaded. Under light loads, fuel octane really is not a power limiting factor and the timing is adjusted normally. When more power is asked for,, the fuel octane rating comes into play and the ignition timing has to be retarded from that optimal for higher rated fuels. This reduces the power output somewhat, will cause higher heat loads on the radiator, and lower fuel mileage. If you don't use or call for the power potential of the high test stuff, 87 might work just fine. I would NOT recommend pulling a load up a long grade on a hot day though.

usually welding the old one will last forever. All the stress has been relieved when it cracked.

You got a GREAT DEAL and fantastic good price on that job. AND you are lucky to still have a wife and the vehicle. HE was with her that day. Presumably the cracked rotor had lots of runout and pushed the pads way back on that wheel. Then when the pedal was pushed-NADA pedal to the floor--- UNLESS you pumped them to add more fluid in the circuit. Also lucky the rotor didn't jam against the caliper and rearrange lots of expensive suspension stuff.

The AHC system is extremely reliable provided: Fluid gets changed every 5 years/60K miles and not contaminated with water, brake fluid etc. The 4 strut accumulators do 'wear out' , just like tires and brake pads. The 'rubber' diaphragm material ,like all polymers, continues to harden with time. After 4-8 years, depending on temperature history and road conditions, the diaphragm will develop cracks and eventually the gas gets out. Go ahead and enjoy whatever ride setting you want, it will not in any meaningful way influence the accumulator life. You ARE well out on the life experience curve. 4-6 years is much more typical, but I have a neighbor with a '98, 75K miles, looks new, and rides perfectly. However, I am willing to wager a single trip over real bumpy roads with a heavy load will finish off the accumulators. Heavier loads and rougher roads do cause the diaphragm to flex more and an old stiff one will be much more likely to crack and let the gas escape into the oil and on out the reservoir vent. Dealer prices to replace all 4 runs $3000+/- However, you can buy a better product on my web site (activesuspensionsystems.com) for $1400, and any mechanic can easily follow the installation procedure--no special tools or training needed. Figure at most 2 hours (really less than an hour). So total cost is about $1600--with a 3 year parts warranty.

As long as the vehicle rides good, the accumulators are fine. I suggest you add 1 quart of AMSOIL Shock THerapy-5 to the AHC reservoir. This is an excellent hydraulic fluid with additives that will help keep the shock seals soft and working. Slight seepage is normal. Drips on the pavement a little too much. Check the color of the AHC reservoir--if the fluid is not clear to very light amber--it was not changed. Some ne wOEM fluid has a light RED tint to it. To check the accumulators, drive one wheel at a time up on a curb (gently, then back off quickly to 'drop' it onto the pavement. Good accumulators will absorb the bump, flat ones will be bouncy-bouncy.

Is there a way to "lock" the AHC in low for improved stability, etc. during highway use? No the system is designed to go into N when it starts moving. One CAN adjust all four height sensors so that N is really Low, but then that results in always running LOW RIDER, with out of whack front suspension camber. leading to rapid inside edge wear.

I should change just the fluid? Or the accumulator on the front drivers side? The truck still rides very smooth....though a rattle trap. Most probably the torsion bar mount is loose on the sagging side. Tighten all the bolts. Then , with the weight OFF the wheel on the low side, tighten up the adjusting bolt one half a turn at a time till the height (after bouncing a few times) is right on. Simple adjustment Remember me when you DO need accumulators (B&BSuspension) 'activesuspensionsystems.com

Moisture did not cause accumulators to wear out. They simply fail from age and internal flexing. Please go to my website 'activesuspensionsystems.com' and read all about it. At the Dealer expect to pay between $3500 and $4000 for the parts and labor. From me, a better part , 3 times the warranty, DIY for $1400 total. Labor to install by a mechanic 1 hour total.

How does the vehicle ride? Is is bouncy over bumps or smooth and well damped. Flat suspension accumjulators will allow road shocks to toss things around real good. The ride SHOULD be excellent, even on bad roads.

Leaking shocks may be salvageable. There are several great products used on motorcycle forks that rejuvinate hardened seals. However, IMHO, the first thing to do is replace the flat accumulators. Leakage is not a typical condition for LX struts. Have you replaced the old AHC fluid yet?

If your LX-470 has adjustable height , the problem is the accumulators for each wheel shock are low/flat. Go to 'activesuspensionsystems.com' and read all about it and what to do.

Why not remove the height sensors, dry them out thoroughly in a 200 deg oven overnite, then thoroughly waterproof them. Also check the connectors the most likely cause. Dealer item only

I have sold over 100 sets of accumulators so far. I would give the struts (shocks) a chance with new accumulators before changing them. If you do change them, I would like the old ones to use as 'cadavers' to see if I can get replacement seals for them.

Toyota has thoroughly tested the OEM filter assembly in al kinds of conditions. It IS the best overall for the vehicle. Lots of hard technical research was done by the Q45 tuners (some of those guys really run those hard) comparing stock vs K&N pop charger cone filter. The stock set-up feeds cool ram air from a the highest pressure area in front of the radiator, while the K&N set-up uses under hood (hot) air from a significantly lower air pressure region. :cries: At the throttle butterfly, the stock air filter flowed MORE #/hr of air than the K&N in all conditions. Stock filter also removed more very small dust particles than K&N (both kept gravel and big dirt particles out, but the small stuff is what eats up engines.) Folks who had K&N filters were losing mass flow sensors due to erosion of the hot wire. :chairshot: Recommendation is to stay stock unless you ford deep streams in which case you want a snorkel in any case to avoid water ingestion

With that age and mileage, the front and rear accumulators are probably getting near flat. THis will cause a choppy, bouncy ride over undulations,speed bumps,etc. THis will cause a host of problems if allowed to continue. Please see my website 'activesuspensionsystems.com' for lots more on the AHC and accumulators.

Emptying (and refilling) the reservoir is first step. Then raise the vehicle all the way. Then, starting with left rear, open the 'brake bleeder' located on each of the ride control valves just above the accumulators (on each side, under the running boards, between front and rear wheels. Be careful because the vehicle will drop down as you bleed the old fluid. When it stops coming out a bleeder, close it, restart and let it raise up again, go to the next closest to the reservoir. LR,RR, LF,RF. BE sure and refill the reservoir as required.

I do hope you had them change the belt tensioner and idler bearings while they were there. While they may not yet be at end of life, they ARE quite advanced toward failure from an age and hours of service veiwpoint. Belt tension (and resulting load on the tensioner/idler bearings) is CRITICAL to service life. Just a little too tight shortens life by 10 fold!