Yes, didn’t make any difference. (It took me a while to get around to it and I had been holding out hope that would do it.)
I did see a drop after changing out the globes, which also makes no sense to me.
The ABCs of AHC - How to Measure, Flush, and Adjust all in one place (5 Viewers)
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Yes, didn’t make any difference. (It took me a while to get around to it and I had been holding out hope that would do it.)
I did see a drop after changing out the globes, which also makes no sense to me.
I did.
ramangain
Clarksonian disciple
With your sleeping platform, you put weight behind the rear axle. Think Porsche 911 engine placement. This puts essentially all of the weight on the rear springs. Even with spacers, you may still be above spec. To get back into spec, you would need beefier springs, or consider adding airbags to supplement the rear springs (cheaper, more flexible, but not a set it and forget item).
- Thread starter
- #144
Highly recommend the King springs for anyone on the fence about new OEM springs. They’re not much more money, just have to go get them on eBay or another place that will have Aussie vendors. They seem to ride fine even on an unloaded truck and basically future-proof the AHC for any weight additions.
The best place to look up parts numbers is Toyota parts catalog - https://toyota.epc-data.com
It defaults to Japan, but you can choose Europe, USA or General (Aus, Middle East, Asia, etc). It links directly to Amayama for price reference.
Does anyone know the full total capacity of the system? Mine has been refilled with green fluid, I suspect Citroen, that I will be replacing. Lots of it is already drained, so can't measure what is inside.
My understanding is that when flushing, not insignificant amount remains in the "shocks" for example. My system was drained and the "shocks" removed, yet they are full of fluid. If a flush is usually ~3 litres, can I assume double that?
It defaults to Japan, but you can choose Europe, USA or General (Aus, Middle East, Asia, etc). It links directly to Amayama for price reference.
Does anyone know the full total capacity of the system? Mine has been refilled with green fluid, I suspect Citroen, that I will be replacing. Lots of it is already drained, so can't measure what is inside.
My understanding is that when flushing, not insignificant amount remains in the "shocks" for example. My system was drained and the "shocks" removed, yet they are full of fluid. If a flush is usually ~3 litres, can I assume double that?
Judging by how long it took me to get mostly clear fluid from every port, I would guess total capacity around 5-6 liters.
ramangain
Clarksonian disciple
Get at least 6 liters if you want to fully evacuate any old fluid (and all of the debris it is bound to bring with it).
I’m using the SS1 (30 pounds) and I’ve got a pretty thick rug lying on top of it. Even with the rug it seems unlikely to weigh as much as the rear-most seats. I’ve always assumed that those seats are considered part of the baseline when measuring pressure - that is, that you measure with the seats installed and with have a full tank of gas, no other load.
ramangain
Clarksonian disciple
FWIW, I just checked my AHC pressures. Unknown age on my stock LX (rear) springs on an 01, 200K miles. No spacers. I also removed my jump seats, but had a full tank of gas and loaded up the rear hatch area with about 100lbs. of additional weight.
My front pressure was 6.7 and rear pressure was 7.3. The rear pressure was 6.9 when I measured a few months ago with no additional weight in the rear hatch, but both 2nd and 3rd row seats removed, full tank of gas.
I do have rear airbags that I forget are there, and hence stay deflated unless I inflate them to hitch up to a trailer.
I just found the specs again for the rear: 5.7 +- 0.3
Seems like I need to look at some beefier springs myself. Oh joy.
My front pressure was 6.7 and rear pressure was 7.3. The rear pressure was 6.9 when I measured a few months ago with no additional weight in the rear hatch, but both 2nd and 3rd row seats removed, full tank of gas.
I do have rear airbags that I forget are there, and hence stay deflated unless I inflate them to hitch up to a trailer.
I just found the specs again for the rear: 5.7 +- 0.3
Seems like I need to look at some beefier springs myself. Oh joy.
Spacers would seem a better idea than stiffer springs, no? My pressures are not quite as bad as yours, and I planned on adding a 30mm spacer 'eventually'.
Slee always seems out of stock, but other options look to include Ironman4x4 and Dobinsons 80 series rears.
Slee always seems out of stock, but other options look to include Ironman4x4 and Dobinsons 80 series rears.
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I am currently at 6.8 in the front and 7.1 in the rear. Are all spacers created equal? 80 series fits 100? Also, what if I tried a 40 or 50mm spacer? Would it lower the pressure more?
I just can't see going from 7.1 to 6.6 improving my ride much. But, I agree that new springs will drop it too low.
Side note: when I am creeping and come to an abrupt stop, my vehicle shakes forward/backward for about 3-4 seconds. Is that normal with hydraulic suspensions?
Mine does not shake as your mentioning even when fully loaded with drawers, sliders, fridge, 10 gal water etc.
Not sure what causes that. Worn body mounts maybe?
Check all bushings, motor mounts, trans mounts, etc... There's a mount in each shock, 8 in the front A arms, 10 in the rear arms, two on the engine, one on the trans, three on the front diff, etc.... Lots of rubber to wear and cause all kinds of sloppy/bouncy feel.
Lovely. I change my 3 points for the front diff per your excellent YouTube videos during "naptimes", lol. Thanks for your advice and support to your fellow cruiser fam.
Good morning group from an icy Kentucky. I'm currently working from home and have a great deal of extra time. So, having recently purchased a 1998 Lexus LX 470 with 237K on it I'm still deep in the throughs of frenzied research and the honeymoon period.
The truck is in remarkably great shape for its age and had a great service record and at the time was the only one within 500 miles of me in my price range. So I made the plunge and she's ours. We are the fourth owner and she was maintained flawlessly according to Lexus records up until about 10k ago.
I don't know about you guys but I've wanted a Land Cruiser since I was a young man (I'm 53 now) and ironically could only afford one many years later... I digress. I give a whole diatribe on how I chose this truck and why in another thread. That being said, I'm going through her pretty thoroughly (When I say I that's my very trusted mechanic and I). I'll do the body, suspension, power steering flush, heater t's etc.. I'll have him do the timing belt, pump, serpentine etc.
It's at his shop now being checked out for a random "fire and no start" issues early this week (it started as soon as AAA got here of course but hey its free so I had them drop it there). I was taking it there anyway to be checked out (check engine on PO says it's an O2 sensor). I've ordered an OBD2 reader that should be in any day.
All that being said here is my question:
The AHC currently goes into the N and L position. It will not go into H. It seems to be working. You can hear the pumps and it leveling. The level in the reservoir changes from L to N. But, will not go any higher. It even changes height when in L once moving. Just no H. So, that would tell me the system is "working" somewhat.
Question 1. If I can't do a graduation test where do I begin? Is it just low? Could I add fluid see if it raises then do a flush later? Just kind of don't know where to start? All the information I've seen starts with assuming everything is working - i.e. the graduation test. The fluid is expensive as you all know and I don't just want to go throwing it away.
Question 2: It seems to ride just fine now - actually very nice. Telling me the globes and system is again, "somewhat functional." What is the harm in not addressing the AHC? I have timing belt and other "essential maintenance" to get though in the next couple of months. Can this wait for warmer weather assuming simple adding fluid doesn't fix it? Can it wait on my list? Looks like I may be dealing with the known "fuse box" issue also...we'll see what the mechanic says today. Just trying to pick my battles as I rides just fine today. There is a lot of rust around the components and I'd like to soak them down for the next month with some WD40 and penetrating lubricant before I attempt to turn the first wrench. Thoughts?
- Thread starter
- #160
Hey Todd, welcome to the club. I'm not too far north in Cincinnati.
Re AHC, you won't be able to do a graduation test until you can go into L, N, and H. You can add OEM AHC fluid to your reservoir now, but that likely won't fix the problem. The pump doesn't care if the reservoir is low and will just suck air into the system if that's the case. If you have air in the lines, that may be preventing you from reaching H, but likely also would prevent AHC from moving much at all and the ride should be terrible. A full flush to get air out would be the solution to this, though I don't think it's your most likely issue. Where is the fluid level in the reservoir when in N currently?
What you really need to start the process is a means to measure the AHC pressures. Whether that be Techstream, one of the compatible wireless OBD readers (see my original post), or a mechanic/friend with access to one of those. Since going into H requires the most pressure in the system, my guess is that your N pressure is near the max allowable by the system and so you can't reach H. Cranking torsion bars in the front will likely help this, you may need new springs or to add spring spacers in the rear to help there.
Downsides of riding as you are include: extra pressure exerting extra wear on all the AHC components, worsened ride (even if it's "pretty good" as is), as well as higher likelihood of defaulting into L if you load the truck up with people and gear.
Hope that helps. Long live AHC!
