Pin Hole Leak Detection in Mobile Hydraulic Systems.

With the system shut down and all trapped pressure released, wrap the suspected areas in Toilet Paper. Start the hydraulics and watch for wet spots.

Might work?

What is the name of this kit and what auto parts stores carry it?

You can concern to "Hydro or Helium Leak detector" for your purpose.

Good luck.

What do you mean by hydro or helium leak detector?

Does he have to buy an expensive machine for leak testing??????

Your project is personal purpose only, Is not it?

I think it is not a project. just an item of his work.

A helium leak detector uses a mass spectrometer to measure the number of helium molecules that leak from or into your system. They are coupled with a vacuum pump and can cost more than $20,000. These devices are usually used in production lines and wouldn't work for your system anyway because the system is full of oil. You would have to drain your system entirely and it still wouldn't be clean enough to run a mass spectrometer. You would burn out the fillament in the device because of the oil contaminant

you can use sensor thermography

to detect the leak on your system

the temperature while leak or not is different, isn't it??

predict the critical part of the system and use temperature analysis there

I'm assuming that -4 & -16 refers to 1/4" and 1" pipe work. If your system can run as high as 30,000psi(g) you have probably got more problems than just a "pin hole leak"!

I would not want to be anywhere near your vehicle while in operation!

One cautionary note:- Don't check for leaks with your finger! And when you find out that your "pin hole leak" is in-fact a stress fracture...............!

If your hydraulic system is working at 4000 PSI, you will usually only see that pressure while the hydraulic circuit is actually working at high load. Try to pressure clean the area where you suspect the bad tubing is. If you operate one circuit at a time, against an load, then inspect for wetness You should find witch tube is leaking. Where the leak is along the tubing should not matter. You need to replace the entire length. Do not try to repair leaking tubing. If the tubing has a bad spot in it. That section of tubing is all bad. If the leak is that small the dye should help a lot. But it will help only if the area is clean enough to allow you to find it. be very careful with these high pressures. Another thing that bothers me is the climb to 30,000 psi. How does the pressure climb to more than seven times system pressure? Good luck, and let us know some more information to further help.

The suggestion in post #2 is excellent. If for any reason that is not a practical solution for you, or just doesn't work, here is another idea:

Drain the hydraulics and pressurize with air, perhaps 100 psi or so. If the leak is truly a pin-hole and not a structural crack, the following method should work. First, observe how quickly the system bleeds down by monitoring the air pressure. This should tell you if you have a relatively large leak or a very small one. Second, if the system holds air at 100psi fairly well, your problem is probably NOT a pin-hole leak, but a structural crack. Why is this? The 100psi is probably not enough to flex the cracked open, whereas your 4,000 psi WILL distort the crack and leak oil.

Finally, to locate a pin-hole, or a really bad crack, make a soapy solution from dishwashing detergent and water, or even children's "bubble blowing" liquid, and apply with a brush or spray bottle a little at a time to suspected areas, especially joints and fittings. Some pneumatics distributors even sell a commercial product ready to use, usually called "Leak Detector Solution", or something like that.

Test your solution by creating your own test device from a piece of tubing with a fitting on one end to attach to your air supply and a replaceable end cap that you pierce with a pin-hole and/or crack the joint where it attaches by NOT fully tightening the threads on a tapered pipe fitting or, if an o-ring seal is used in the fitting, by nicking the o-ring with a razor blade or sharp knife.

A large leak should blow a large bubble or multiple bubbles very quickly. A very small leak could take some time for the bubble to become large enough to be seen, so be patient. If your solution is not at the correct strength, only tiny bubbles may form and pop too quickly. Look for foaming or a spot with a colony of hundreds of tiny bubbles forming and popping.

Using this method with helium instead of air will show very small leaks that won't show up with air. -- JHF

Go to www.spectroline.com They have a dye you can put in the system and find the leak at low or high pressure. Will not harm the system.

From Dave at dkmann@airmail.net am a Mfg. Rep for the company in Dallas