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Micro Leakage Hydraulic testing
- Thread starter mikebramel
- Start date
Thanks for sharing, anyone ever use one before? I have a few machines that I could use them on now to isolate a drifting cylinder or leaking control valve, anyone ever use anything else to locate the problem with, the only ideas anyone locally had was to cap the cylinder and eliminate that from the equation if it still had the problem it was the cylinder, if not it was in the valve.
John C.
Senior Member
Randy88, the cap and load the opposite side of the cylinder is pretty much the easiest and fastest way to get it done.
It looks to me like the guy is working hard to sell a kit. I have a porto power pump for my jacks that I also use for the same purpose. Mostly though I used it for setting circuit relief valves without having to run the machine. The problem with using it for these purposes is the amount of oil you have to keep putting into the pump just to test a component. Imagine trying that test on the boom circuit for a 365 Cat excavator. I've yet to see a Komatsu excavator that didn't leak by the spools when cold. Also I'm thinking the gentleman is taking some liberties in saying that he invented the process. I've known a few wrenches that worked for Washington Iron that used a porto power for checking circuits back in the sixties and seventies. I first saw it done in the early seventies while in the navy. It was used to check the settings of anchor windless brakes.
Today's hydraulic valves are designed to leak some when cold and to seal up as the machine warms up. There are also a lot of components in valves that have leakage designed in for other purposes. I'm sure a lot of the wrenches on here have many ways to check leaking circuits that don't involve a porto power. I've used a stethoscope or large screw driver as much as anything. If I can't identify the leak that way I start using a logic process and check the possible leakers in order of likelihood and/or expense.
It looks to me like the guy is working hard to sell a kit. I have a porto power pump for my jacks that I also use for the same purpose. Mostly though I used it for setting circuit relief valves without having to run the machine. The problem with using it for these purposes is the amount of oil you have to keep putting into the pump just to test a component. Imagine trying that test on the boom circuit for a 365 Cat excavator. I've yet to see a Komatsu excavator that didn't leak by the spools when cold. Also I'm thinking the gentleman is taking some liberties in saying that he invented the process. I've known a few wrenches that worked for Washington Iron that used a porto power for checking circuits back in the sixties and seventies. I first saw it done in the early seventies while in the navy. It was used to check the settings of anchor windless brakes.
Today's hydraulic valves are designed to leak some when cold and to seal up as the machine warms up. There are also a lot of components in valves that have leakage designed in for other purposes. I'm sure a lot of the wrenches on here have many ways to check leaking circuits that don't involve a porto power. I've used a stethoscope or large screw driver as much as anything. If I can't identify the leak that way I start using a logic process and check the possible leakers in order of likelihood and/or expense.
mikebramel
Senior Member
Thanks for the insight. Don't take this the wrong way but you or the people you worked with never offered this information in video it's only till now that you are sharing this, this guy did. That kit he sells is considerable money but the book is only $75 and is over 400 pages and spells everything out step by step. It's not really about absolute zero leakage or not, but the leakage rate that will determine whether you go farther into the unit. This is also just about the only way to test most subplate mounted valves
UK pie-can
Member
There are Kubota Service Training CD's that date back to the early 1990's that use the exact same method using an OTC or SPX Powerteam hand pump. 
The cap & plug kits have been available in most hydraulic stores for a good number of years....This method of leakage analysis is NOT quite as "Revolutionary" as this guy makes out.
The cap & plug kits have been available in most hydraulic stores for a good number of years....This method of leakage analysis is NOT quite as "Revolutionary" as this guy makes out.
I have a control valve on one of my dozers in the shop now, we're discussing rebuilding it, we're having issues with the pressure testing we've done to it, and one of the guys thinks its the culprit to why we took out the clutch's in the transmission and we should go through it, is there any way to static check the valve with a port-a-power to be sure its either leaking or not? I got to thinking about this thread and was wondering if its possible and how to go about it?
UK pie-can
Member
UK pie-can
Member
Hi Randy88,
The configuration of the control valve will determine how straight forward the test will be.
By that I mean a closed centre, open centre, float centre & tandem centre control valve work differently.
The best way forward would be the use of a hydraulic schematic or someone that knows your particular machine & control valve....if that's any help.
Mobiltech
Senior Member
Yeah if the nut was loose on the piston he may have missed it that way.
He seems to be high on theory but low on practical knowledge.
John C.
Senior Member
Randy88, I've always tested transmission valves in the machine with it running and the gauges installed in the specified ports. Usually clutches go bad when the piston seals start leaking and not because of a transmission control valve leaking. The other part of that problem is that transmission control valves usually have tubes with O rings that the valve bodies sit on top of and are held down with bolts. It's not real easy to make caps and plugs that would enable you to pressure test each port of the valve. The other part of the problem would be interpreting the modulation systems that make shifting easier on the transmission components. Unless the valve body was split or there was damage to the spools or bores, all I've ever done was check the spring heights and put new seals in.
What make and model of dozer do you have?
What make and model of dozer do you have?
Thanks John, its a komatsu D85-12 dozer, the first gear clutches are totally cooked, when we did the testing before taking it apart, we got varied pressure readings, a few were thinking the control valve was leaking and part of the problem, was just curious if it could be static checked for leakage before we fired it up or just resealed the whole valve assembly.
John C.
Senior Member
It kind of sounds like the clutch pack was slipping for awhile. I don't remember but does this have fiber seal rings or cast iron?
You could probably build a plate and clamp it against the bottom of the valve and individually test each valve position. Lots of work when most would visually check the components. I know it's also a lot of work putting the unit back together and loading it back into the machine not knowing and having the chance of it slipping again.
Any idea how many hours are on the tranny? Have you pulled the torque converter? Sometimes there are multiple leaks and the pump just doesn't put out enough oil any more to supply everything.
You could probably build a plate and clamp it against the bottom of the valve and individually test each valve position. Lots of work when most would visually check the components. I know it's also a lot of work putting the unit back together and loading it back into the machine not knowing and having the chance of it slipping again.
Any idea how many hours are on the tranny? Have you pulled the torque converter? Sometimes there are multiple leaks and the pump just doesn't put out enough oil any more to supply everything.
Torque is out and apart, tranny was supposed to have a few thousand hours on it, but no way to verify that, all the parts are supposed to be in early next week to put both back together again.
This tranny has cast iron sealing rings in it, which are coming new. As for the control valve, we'll probably just put all new seals and gaskets in it too, was just hoping for a simple quick easy check and it never hurts to ask, someone might have an idea we didn't think of or could figure out how to rig it up.
This tranny has cast iron sealing rings in it, which are coming new. As for the control valve, we'll probably just put all new seals and gaskets in it too, was just hoping for a simple quick easy check and it never hurts to ask, someone might have an idea we didn't think of or could figure out how to rig it up.
That seems to be the case with everything I have ever seen from that guy, and with most of techs/engineers coming from the industrial sector to mobile hydraulics.
They have a very illogical way of analyzing everything compared to the way mobile hydraulics are designed and work.
I suppose there is a market for this sort of thing, where it's step by step and allows you to isolate without having that visual in your head of how the system works. He's pitching to the people who are scared to "staht the engeen"
Having that mental image of how the system operates in your head while your butt is in the seat and you're pulling levers is a place that takes work and time to get to.
I want to see how much pumping he does on the 994.. He's gonna be pumping that little porta power for a week.
Parts changers who will never invest the time to learn may benefit from this kinda kit, but that will never make a good tech or have the accuracy and care of a real tech.
and overglasses hanging 2 inches off his cheeks? Wouldn't a guy that is serious about safety invest in some real prescription safety glasses? I'm glad he has them on (many youtube videos **** me off with no eye protection) but I wouldn't work on hydraulics with that poor level of eye protection. Not in front of an audience while preaching safety.
of course a lot of components drift and leak internally when at operating temp. He is testing everything stone cold. The more I watch it the worse it gets and it's making me angry.. lol
Over confident salesman playing the role of a tech and it's just wrong.
time for me to get off the internet and go do some work.
Over confident salesman playing the role of a tech and it's just wrong.
time for me to get off the internet and go do some work.
John, to be honest, we didn't see anything really wrong with the sealing rings and bore they were in, but I need to inspect it really close when we clean it all up to put it back together, my parts never showed up this week, so the inspection process is on hold for now and everything is under a cover to keep the dust off.