Air Suspension valve, leak tester

[Peter Sanders]

This is a simple device. A single unit could be used for all four valves, but four devices allows testing the valve block at one time and allows comparison between valve pressures.

I made four of these devices specifically for the early Range Rover valve control block. I am sure it will work with any other valve block, perhaps a change of connection is required.

The tester is an aluminium block with four holes. One hole is drilled (centrally) along the length of the block and three other holes drilled in to the top of the block, intersecting with the hole along the block length.

The holes are tapped 1/8th BSP. The photos show the configuration. The device has a small pressure gauge and two Schrader tyre valves. Only a single valve is required for the device to function as a leak tester. The second valve was installed to test and confirm the pressures displayed on a remote type pressure monitoring system.

Using the four devices I could check the pressures as often as required. This was usually on a daily basis, leaving the valve block under pressure for an extended period.

Using these devices, I discovered something I had wondered about for a while. Does a 6mm ID O ring work well with a 6mm OD air line?

The valves in my particular valve block did lose pressure very slowly over a few days. I decided to try 5mm ID O rings. These retained the pressure for a much longer period, several weeks (?).

The Schrader valve is used to pressurise the device(s) and only a "spoonful" of air is required to set the pressure to 30-50 psi. This is about the pressure range for normal RR air suspension.

The testing did show that some valves retained pressure better than other valves in the same valve block. I did need to tighten some of the mounting bolts to stop some (otherwise undetectable) very small leaks.

The single pressure gauge attached only to an air line is used to pressurise the on board air tank or reservoir (via a Schrader valve) and confirm no leaks in the tank or air line from the tank to the valve block.

[DIYer]

Thanks Peter Sanders! We've added your Air Suspension Tester to our Suspension category,
as well as to your builder page: Peter Sanders's Homemade Tools. Your receipt:

Air Suspension Tester by Peter Sanders

tags: suspension, tester

[Toolmaker51]

Oooooh I like this, what with adding supplemental air bags to a few of our vehicles. I'd never thought of plumbing a gauge in. Re-pressurizing was lots of manipulation between air hose and handheld gauge, your device could be part of the vehicle as well.
Most I've done are a single fill port, but added to the 'manifold' a needle valve to isolate right from left after filling. In theory it lessens body sway of that side under pressure in a turn, transferring to the opposite air bag. Haven't designed a test to prove hypothesis, mere seat of the pants testing says it works.
In one case, I didn't branch the supply lines to fill from one port, do to unsatisfactory solutions protecting the lines. Put those Schrader valves in web of lower rocker pinch welds.

[hemmjo]

Nice idea. I have Ride-Rites on my Tacoma. I plumbed each side totally separate. It does prevent sway. Thought about a connector between them with a valve, but that just adds a layer of complexity.

I did run a line from each side up to the console and put a small gauge for each side. But I do have to adjust the pressure at the pair of Schraders mounted in back on each side of the license plate. I just use the gauge on my inflator to adjust pressure.

I find that keeping the passenger side 2-3 psi higher than the driver side helps eliminate some passenger side tire spin if I accelerate too quickly. I had a 1999 Tacoma that I wired so I could engage the differential lock using the button on the dash, without using 4WD. But on my 2005 , 4wd, 4wd Low are controlled with a knob instead of a shift lever and the Diff-Lock will not engage unless the knob is in 4 low.

[Toolmaker51]

<<<<<snipped>>>>>>> I find that keeping the passenger side 2-3 psi higher than the driver side helps eliminate some passenger side tire spin if I accelerate too quickly.

History lesson, this is back when tires had become a little more expensive, while gasoline is through the roof. But I still see people sit idling in their car with heater or A/C on. Seems expensive practice, a wardrobe change would do the trick........

[hemmjo]

snip... Seems expensive practice,...snip........

Agreed, the only time I would need it is trying to pull out in traffic, when there are no "long openings". Other than that I am not a "hotrod"... anymore.