I have developed a small hydraulic leak on a the rear valve assembly that all the BH functions are controlled with. This would be a simple fix but I cannot get a wrench to fit on the particular fitting that is weaping due to space constraints. Not sure if you guys know the arear that I am talking about but its right below the control leavers for the BH and all hoses are tied into this valve block assembly
Is there a special wrench available to go on over these fittings to tighten the inner JIC fittings?
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Before you get your head blown off or have a punture injury lets just stop for a minute.
It is not a simple repair.
The back hoe like most others has two sets of valves which include the two for the outrigger foot pads to level the tractor.
The valves are small to fit the design of the back hoe platform period
The valves have a gimbal control set up as they will fit the back hoe design etc.
These hydraulics are assembled from the botomn up no differently than the hydraulics and hoses on a continuos miner-PIA, PIA. !@#$%^&*()_+
The Joint Industrial Council fittings are ment to do two jobs and have a common size range fitting for hydraulic fittings and are designed for high pressure useage.
You may have two problems with out realizing it in your case-
The male JIC fitting exiting the gimbal control valve may have a male BSP thread British Standard Thread fitting which requires a back upwasher to provide pressure against the BST o-ring to the sealing surface of the valve body.
The BSP fittings allow for simple adjustment of the fitting and hose path prior to fnal tightening-which means very low wrench forceas the o-ring could be damaged.
If the valve Gimbal has BSP fittings the fitting may have a bad oring and the fitting must be removed and replaced with the proper BSP o-ring-no standard o-rings do not fit and they will leak at low pressure!!!!!!!!!!!!!!!
BSP o-rings have the blue paint dot to identify them.
In the case of the pipe thread JIC fittings the male end fitting with a tiny bit of pipe dope is installed in the valve block at a moderate wrench pressure-too much cracks the valve block.
You would not believe how little pipe dope tape will break a hydraulic fitting-no you cannot use pipe dope on a JIC fitting.
If the Male to male Jic fitting is offset at 30-45-90 degrees the other valves hoses may have to be routed around this fitting to travel to the specific cylinder.
The male fitting exiting the block may be loose or weeping and you can not see this with out removing and plugging the hoses with male JIC plugs and labeling each hose prior to removing it.
if the female JIC swivel fitting is loose in the rear portion of the valve there is no easy way to tighten it unless you remove the other hoses and plug them.
sorry about that part as an angle wrench will not fit easily either.
The female JIC fitting may also be cracked and weeping and you would not see this as well until the hose is removed.
The male JIC and female JIC hydraulic fittings are designed to tighten easyily and quickly with little force other than to make sure the fitting does not twist freely. as the hoses are disposable and the fittings are not reusable care must be taken to assure that the female swivel fittings are not damaged- when you plug the female fittings with the JIC plugs they will pull in freely and stop with a little bit of wrench pressure.
before attempting to remove any hoses fromn the valve body-
do not use the transport pin of the back hoe!!!!!!!!!!!!!!!! as a method to hold everything in place.
1. fully extend the dipper bucket to its fully dumped position.
2. fully extend the crowding boom(the outer boom) to its maximum length.
3. fully extend the main boom forward to its maximum position
4. lower the main boom to the ground and simply allow it to rest on the ground with no pressure.
5. lower the outriggers but do not exert any down pressure on them.
shut the tractor off and rotate the gimbal valves to release any pressure in the cylinders-keep doing this until you feel comfortable that all the remaining pressure in any of the circuits is gone completely.
before you loosen the first female swivel fitting-be very sure you have a very heavy rag or towel over the fitting to prevent any oil from spraying out.
If you have a small piece of plexiglass to cover the area in front of the valve when you remove the individual hoses I would feel a bit better as oil puncture injuries are not survivable.
leon
you will know when all the residual pressure is gone from the cylinder cicuits when the cylinders stop moving as they are holding the system pressure until the valve is moved.
you can safely remove the hoses and label them to find the leak.
You need the proper female JIC caps to plug the male fittings exiting the valve block to check for leaks.
After the valve ports are capped and the hoses plugged with the proper fittings you will be able to determine which one and what is really leaking.
to do this remove one hose at a time label each hose one through four and tag each male fitting coming out of the valve block as one through four to keep track of the hoses and routes. Its faster than spray painting each fitting and less messy.
in some cases a longer extended male or female JIC fitting is used to pass over the other fittings to ease plumbing and hose routes.
leon
