Amphibious HEMTT

[WaterH]

One possible solution. Fit two of the truck/trailer height control valves at different ride heights and run a pneumatic switch to select between them.

On-road, off-road and vent (slammed) would be pretty easy.

You realize to do what you’re suggesting would require 8 of those valves and it would be a maze of plumbing.

This is the best solution.

My biggest complaint is in the morning the truck is not like it was the night before. (Because of leaks) I admit it would be cool to just hit a switch and it be at a desired ride height, but that’s not really a complaint. Those height control valves would only work when there was pressure in the tank, so if I want the truck to be correct when it sits for two days, (or a week) I would need to leave the compressor on.

Whatever I do, I need to fix the leaks. I changed the 4 push connect fittings last night. I’m hope for a pleasant surprise when I go out to the shop today. Even if they are fixed, I still have two other problems with the system. I think the brand new pressure guage from McMaster has a slow leak. (It might be the short tube the goes from the manifold block) The rest of it I had under water with no bubbles. I also have a leak in the plumbing back at the tank. There’s quite a few fittings and adapters back there and I’m not sure where it leaks. A lot of it is tucked inside the frame. So general PITA.

Those manual valves will eventually leak if they don't already. Sometimes they will leak up.
As for the overheating, is air not thinner in summer and have less oxygen to burn?
I always thought egt problems got worse in the cold.

Are you saying you have experience with those particular valves or just all valves will leak. They appear to be very well constructed. I have considered 4 ball valves if they truly won’t hold up.

On the temperature, it is true a diesel runs cooler when lean, but I have never heard of edt getting worse in winter.

 

[2big bronco]

I would think egts would get better in the cold as air is denser correct?

 

[WaterH]

I would think egts would get better in the cold as air is denser correct?

I’m not sure if it’s because of denser air, but my experience is EGTs go down with outside temps.

So I just checked the truck and it appears the new fittings fixed the leaks from the valves to the bags. (The truck is with in 1/8” at the 4 corners) Fingers are crossed. I think I have one more push connect fitting in the back on the main line coming from the tank forward. I wonder if that could be the tank leak.

 

[elbekko]

One possible solution. Fit two of the truck/trailer height control valves at different ride heights and run a pneumatic switch to select between them.

On-road, off-road and vent (slammed) would be pretty easy.

As WaterH said, that's just a maze of plumbing for something easily fixed with some basic electronics

All you need is 4/5 solenoid operated valves, and whatever system you desire to control them based on some height sensors. Hell, all of this can probably be done with some off the shelf industrial components.

Or grab an OEM system from the junkyard and be done with it.

 

[Dougal]

You realize to do what you’re suggesting would require 8 of those valves and it would be a maze of plumbing.

Yes, but avoiding electronics that's where you end up. Computer circuits were once pneumatic logic with simple switches and check valves providing all the outputs. Anything is possible with pneumatics if you're dedicated enough.

I reckon it could be done with 4 of those valves though.

As WaterH said, that's just a maze of plumbing for something easily fixed with some basic electronics

All you need is 4/5 solenoid operated valves, and whatever system you desire to control them based on some height sensors. Hell, all of this can probably be done with some off the shelf industrial components.

Or grab an OEM system from the junkyard and be done with it.

I know it's easier with electronics. He doesn't want electronics though. My 1993 RRC system is a great example. A potentiometer on each corner, a valve for each corner and a programmable controller. Could probably be done with arduino these days.

 

[Bacho]

Had an F450 with the mechanical ride hight valves. Worked great. Wired in a dump solenoid to dump the rears when hooking to a trailer, that worked great. If you let it sit a long time, yes the system would have to wait on the compressor.

I would think with some electric solenoids you could great a dual ride height without miles of plumbing and no computers.

 

[elbekko]

I know it's easier with electronics. He doesn't want electronics though. My 1993 RRC system is a great example. A potentiometer on each corner, a valve for each corner and a programmable controller. Could probably be done with arduino these days.

Yup, we're in agreement there. The RRC system (99% the same as on my 1999 P38, by the way) is beautifully simple, mainly let down by 80s electronics. Pop in some better valve drivers and a more robust ECU, and it'd be perfect. Hence my suggestion that it could also be done with off-the-shelf industrial components, but at a greater cost most likely.

I just didn't want to explicitly mention it because someone would just go "ermahgerd Land Rover sux"

But yes. If you want a simple multi-height air suspension system that's easy to integrate, go steal one out of a 1st or 2nd gen Range Rover in the junkyard.

 

[WaterH]

I know it's easier with electronics. He doesn't want electronics though. My 1993 RRC system is a great example. A potentiometer on each corner, a valve for each corner and a programmable controller. Could probably be done with arduino these days.

But yes. If you want a simple multi-height air suspension system that's easy to integrate, go steal one out of a 1st or 2nd gen Range Rover in the junkyard.

Actually, I allready have a simple muli-height suspension. Quite honestly, I have no complaints except it leaks. The reason a preset height would be nice is so I could get in, turn the battery on and the truck go to the preset. If it wouldn’t leak, I don’t need to do anything. It is so rare that I need to change the height, it’s not a hardship.

Currently I have three leaks.
1. A vary slow leak in the front drivers side. Must be at the bag fitting or the bag itself.
2. The copper tube that feeds the guage in the console. I did some tests and found that I need to have the fittings so tight to hold air, that I will need to mount the plumbing in a vice. This is difficult now because I installed the “never leak” fittings. They are hard to take apart. I’m temped to just plug the guage hole.
3. A leak in the plumbing in the rear by the tank. There’s quite a few fittings back. More than you would imagine. Shut off valve, quick coupling for air tools, blow off valve, pressure switch to operate the pump and of course nothing is the same size, so multiple adapters.