GRAYM

here's what happened...was driving along and all of a sudden it felt like the rear suspension was just not there it actually felt like it was bouncing on the frame. then it went away. does anyone have any idea what that may have been? I recently in the last year had the rear shocks changed with OEM shocks.....any ideas would be appreciated.

mrblister

Air bags may not of been pumped up leaking or height control or compressor . Can you raise truck up to high then lower it to low then put it at normal

GRAYM

yes I can raise and lower it....now ever since i had this from new in 03 never could understand this system. I raise it to high and then drive it goes back to N...same if i lower it to low....is there a way to keep it in either mode that I am missing? Drove it this morning seems fine. usually happens on the same road in the same place....the road is really wavy etc...normal northeast back road.

mrblister

The low setting is used for slow speed nothing higher then 12 mph The high is used fopr nothing higher then 20 mph. I may have the speed amount I am telling you higher or lower then what they are but once you reach a higher speed in H the suspension will automatically lower it self to N. In Low same thing applies if you go to fast it will return to Normal. It was designed to be used with off road 4 wheel LOW 4 wheel High and Normal. Read your manual it gives a good description of how it works. Or rather when to use it when not to use it.

I am not sure I understand where your bouncy ride comes from unless you have your suspension set to L and then when you reach higher speed the suspension automatically pumps up to Normal As well as if your set to HIGH it will automatically release pressure to normal.when you reach a certain speed

ALAN553

Air bags shot, they leak when the rubber is creased, hence you may be able to get ht control to work but they will ultimately leak down when in motion. They don't last forever, 03? The rubber is cracked somewhere.

Randy20g

Air bags are leaking or a leaking line. I just redid my rear air suspension 2 days ago. I installed new air bags, a new air reservoir (comes with all new lines), new air pump filter and all related rubber hoses. Job took me approx 2.5 hours, mostly due to rusted bolts. The only thing i didn't replace was the working air pump.

All rear air suspension problems now gone.

jpnut

I am close to doing this job myself. Thanks for the follow-up

Randy20g

With the spare tire out of the way and the car jacked up, you can literally sit up under the truck and work. The bags pop right out after removing the clip. If you do the reservoir as well, you don't have to worry about the lines not coming out of the bags. The only downside to that is the cost of that tank. ($590).
My bags and lines lasted 327k miles before it showed the tell tale sign of leaking (bounce house ride). The bags leaked down after about 30 minutes or so after the truck was turned off.

IF you decide to do the bags only, and are going to reuse the lines, there is a special round tool that is helpful in removing the lines. I got it and it did work like a charm. Cost is approx $35. (it's really just a silly little plastic round thing).

I did the rubber hoses as well as a precautionary measure. ALL rubber hoses will get brittle eventually. If you are in there, it pays to replace these parts as well. If you DO decide to replace the air lines with the tank, there are marks on the new lines that correspond to the various line routing clips that are placed underneath for correct line placement. It's foolproof.

GRAYM

sounds good....i have not had this issue now in over a week. so i am not sure why this happens if the bags where bad it should continue to do this but i have not had an incident since. If i go the route of changing out the airbags any idea on the cost at a dealer or i could have toyota do it.

Randy20g

Yes, Toyota can do this as well since the 4 runner had the same suspension available as an option.
All the same part numbers are available from Toyota.

As for cost, I guess that would all depend on what the book labor time is for the job.
It really isn't difficult.

Jeeparn

Randy20g, you mention bouncy house ride... Did you replace your shocks too? Only reason I ask is my GX bounces a little mostly bottoms out on avg to bigger than avg bumps and it feels like it rolls a bit to when pulling out of drive way or turning on to a road that has a large crown in it. Anyways, I was thinking more the shocks are the issue, since one has some oil leaking from it but after reading your notes above wonder if my bags might be worn too. '08 gx with 54k miles.

Randy20g

In order of completion during the last year:

Both rear shocks... 1 actually broke at the mounting point on top...Made the car also feel like a bounce house.

3 months ago I did both front shocks.. They were both leaking heavily and were shot.

Lastly....Rear air components.

Easiest way to determine the sate of the rear bags is to measure the distance from the fender lip to the tire right after you turn it off at the end of the day. Measure it again in the morning.... See if it leaked down. If it has...could be leaking bags, or a leaking line...

BTW....inspect those rear shock top mounting points. I could not believe that left one was broken clean off.

Keep in mind....this truck has over 327k miles on it. I did not touch one suspension part until this year.

Jeeparn

Thanks Randy20g. And wow 327k miles. Impressive!
I think I'll start with the rear shocks and go form there since I know they're leaking I'll also do the measurement test too.

GRAYM

OK this is where we are with the rear suspension issue...I tested out the height control it moves up and down according to how it is supposed to work. So that part is fine...but what i am finding is that when driving, you know how the rear raises slightly and then when you stop you can hear the air being released and it lowers....that part is not happening, but i am also noticing that overall the ride is definitly not good compared to what it used to be. took it on a long trip this weekend and realized there must be an issue....can anyone provide insight on what repairs may be needed to I can prepare myself!!!

Thanks for your help!

mrblister

When driving if your truck is raising then there is a problem. The truck should set at the normal level and adjustments
are made according to the speed for high and low. If your hearing air releasing and the level drops you have a leak .
Your going to have to get a diagnosis so you know where your issue or issues are . Good luck