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Old 07-02-14, 09:17 PM   #1
Caniac14
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Hey all. I have had my air ride installed on my Lexus for about 2 months now.
I am posting to see if what is occurring to me is common or not.

Every morning when I turn the car on to take my wife to work my compressor turns on. This has happened to me since day one of the install. Which is why I don't air out at night now. Anyways. I have a 5 gallon tank and I think my switch is 80psi turn on to 145 turn off. I am just wondering why the air in my tank get's below 80psi at night? My bags are fine and stay exactly where I left them, but apparently my tank get's low enough after a while that the compressor needs to turn on.

Is this normal? Or do I have a small leak on the tank.
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Last edited by Caniac14; 07-03-14 at 05:06 AM..
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Old 07-03-14, 02:17 AM   #2
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Small leak between the compressor/check-valve and the valves/manifold.
Get some soapy water in a spray bottle and give every threaded fitting a couple squirts.
If you used NPT fittings, it's very easy to over/under torque them, used Teflon tape or not enough thread sealant or you pressurized your system before letting the sealant dry!
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Old 07-03-14, 02:25 AM   #3
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Yeah you got a leak somewhere.
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Old 07-03-14, 05:05 AM   #4
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Quote:
Originally Posted by Shmee View Post
Small leak between the compressor/check-valve and the valves/manifold.
Get some soapy water in a spray bottle and give every threaded fitting a couple squirts.
If you used NPT fittings, it's very easy to over/under torque them, used Teflon tape or not enough thread sealant or you pressurized your system before letting the sealant dry!
I definitely pressurized it before letting the sealant dry. Boo-boo on my part. And what is teflon tape? Is that "plumbers" tape? If so I only used it on one fitting I could physically hear and feel the air leaking out of and it seemed to have fixed that. I have tried the soapy water test and haven't gotten anything, so apparently it's not leaking fast enough?

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Old 07-03-14, 05:13 AM   #5
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Another side question. I have noticed that, though my bags are in the exact same spot in the mornings that I left them when I parked, sometimes my gauge will tell me they are higher or lower than what they were(usually not more than a few PSI, never more than 7 or 8). I've been told to attribute this to temperature change from when I usually park it at 5:30pm at 85+ degrees to it usually getting down to 40 at night, and the car settling overnight as well. Seem right to you guys?

And would my compressor immediately turning on every morning as soon as I put the key in the car be a problem on the electrical system or is that fine as well? I have attributed my alternator death to my PS leak from when I bought the car, but the ALT lasted 2 months after the PS fix and only 3 weeks after air install. Coincidence?

I know these are weird questions, and they are minor overall since my setup still works and runs as it should, but I like to know as much as possible bout stuff so when something major does go wrong, I can better access what's going on.
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Old 07-03-14, 09:25 AM   #6
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Add more soap to the water and try again... It might just be in a really crappy spot that is hard to see. If you can feel and hear it, it's a bad leak. What you are likely looking for is minor bubbling which often takes a few second or mins to show past the bubbling caused by spraying the soapy water. Take your time and look at the threads of every fitting really closely!

If you pressurized the system before the sealant was dry, and the fitting wasn't 100% tight, you can blow out the sealant and cause a leak. And yes, Teflon tape is often called plumbers tape... There are also different grades for certain chemical uses.


Yes, air changes pressure with heat. Pressure increases with heat and decreases with cold. Basic physics: PVnRT.
If you have ever filled up your tires in the morning and then rechecked in the afternoon or after a drive or even a blast on the track, you may have noticed the pressure being higher. That is why.


As far as the alternator, if you had a PS leak, that is likely the root cause of the failure. The extra demand put on it from the air system was probably just the straw that broke the camels back. Without the air you might have gotten more time out if it but it's days were limited anyways... Just keep an eye on your charging voltages.

IMHO, the stock 80amp alternator is not strong enough to handle anything more than stock loads unless you live in SoCal, the SW, Texas or the rest of the extreme southern states which don't really need defrost and wipers all going full blast for the year like the rest of us north of them do!

If you have any sort of stereo and air, I would highly suggest getting into a high amp alternator. Even the basic ones should do 80a at idle and probably 160a @ 3000rpm. My mechman does 167a@ 800 and ~320+a @2800, I can run all the Acc on the car, my stereo cranked and the air system pumping away and don't get a flicker at idle... Stock alt would implode! :P
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Old 07-04-14, 06:23 PM   #7
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Shmee - I think you are right about the alternator capacity. Did you also have to change out the fuses (e.g. the 120A one) and the wiring to the battery?
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Old 07-06-14, 12:35 AM   #8
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Thanks a ton for all your answers and input shmee!
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Old 07-06-14, 07:39 PM   #9
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Gene,
When I put in my Mechmann, I did the Big3 Upgrade with extra 0/1 gauge I had for my stereo/trunk install. I highly suggest this for EVERYONE regardless of what sort of demands you put on your stock system. Wiring ages and loses capacity, corrodes and contacts become loose. Upgrading and adding in more grounds at the very least should be something on everyone's project list, even if it is with 4-8ga wiring.

Alternators output "power by demand." So they do not supply full power unless asked to, and only supply as much charging as required. Even though my alternator CAN put out 160+amps at idle, it will only ever put out that much if it is needed, otherwise it will output 5amps, 10amps, 25amps... Whatever demand is asked of it. Same at cruising speeds.

I did not change any of the fuses to the engine/stock harness.
It would be inadvisable to increase the fuse sizing to the rest off the circuits in the factory fuse panel because they will NEVER need more juice. What you can do is run a fuse inline from the alternator to the battery, I've seen lots of guys recommend this online... I'm not really sure why you would do this but it would shunt any overload situation by blowing the fuse... Assuming you of course, removed/disconnected the factory alternator cable, otherwise you'd not only cook that cable but likely cause an electrical fire if that fuse ever blew and forced that 100+amps through a cable originally designed to handle no more than 80amps when it was new...

But i see no point in it because there are so many things that would be going wrong, telling you to shut the car down that there is no point in my eyes!


Kenny,
No worries man!



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