Merrill
Member
So on the jack I have in the area where the spider gear is located, from left to right looking from the jack handle end, there is the plunger, then the "working valve" threaded insert having a plain slot for a screwdriver to remove it, under which are the two ball bearings and the spring (the smaller ball is at the bottom of the shaft, then above it is the spring and on top is the larger ball- the spring is soft , easy to compress, and the large ball sits just inside the first coil of the spring like a cradle; the spring is tapered so that the lower end of the spring is about the same diameter of the small ball which it is pressing on). Then in the middle is the spider valve -which controls a shaft which raises and lowers according to the screwing in or out of the spider gear shaft, and, when the shaft is screwed down, contacts a ball bearing which sits in a cup and seals the machined passage under the ball. Next in line, more to the right is the overload valve with its protective plastic cap.
So, following instructions I released the spider gear shaft so that the lift arm was fully relaxed in the down position; then I pumped the plunger a number of times, while keeping the reservoir full, then closing the shaft/valve and seeing if the jack would pump up, and it would only respond in the teeter totter manner Hiball described. I tried that bleeding process a number of times to no avail. I was lifting and depressing the plunger by hand instead of using the jack handle apparatus. When I lifted up on the plunger it resisted and felt like a vacuum was pulling/holding the plunger from lifting. This with the spider valve open. Using more force the plunger would lift. Then, after closing the spider valve, the plunger upon being depressed would travel to the bottom, and about 1" of the stroke would lift the jack arm but, upon lifting the plunger there is the teeter totter and the arm falls down.
I assume that the plunger ***** fluid from the reservoir on the up stroke through a machined passage connecting the reservoir to the plunger shaft. I don't understand why the plunger would be restricted by some vacuum, with the fluid not freely flowing into the plunger cavity on the upstroke. Perhaps the passage is partially blocked? I also don't see what mechanism then would operate to seal the plunger cavity at the beginning of the down stroke to direct the fluid to the ram. Should be some ball?? I then assume that the fluid should be pressurized to flow to one of the working valve balls, unseat the ball, pass thru to the ram and have the ball reseal on the next plunger upstroke. The teeter totter action would mean that the ball unseated under the plunger pressure is not sealing upon the commencement of the plunger up stroke. I wonder if there are any schematics showing the fluid passages and the operation of the plunger, balls and ram??
So I have to open up the working valve and see if there is any debris in the ball seats or if the ball/balls may be distorted, worn or damaged.
I took some photos of the jack stuff, but I don't see any way to upload. As I remember being on forums years and years ago you have to host the images somewhere to get a url for the forum software to find and display. There is no means of direct upload, correct?
So, following instructions I released the spider gear shaft so that the lift arm was fully relaxed in the down position; then I pumped the plunger a number of times, while keeping the reservoir full, then closing the shaft/valve and seeing if the jack would pump up, and it would only respond in the teeter totter manner Hiball described. I tried that bleeding process a number of times to no avail. I was lifting and depressing the plunger by hand instead of using the jack handle apparatus. When I lifted up on the plunger it resisted and felt like a vacuum was pulling/holding the plunger from lifting. This with the spider valve open. Using more force the plunger would lift. Then, after closing the spider valve, the plunger upon being depressed would travel to the bottom, and about 1" of the stroke would lift the jack arm but, upon lifting the plunger there is the teeter totter and the arm falls down.
I assume that the plunger ***** fluid from the reservoir on the up stroke through a machined passage connecting the reservoir to the plunger shaft. I don't understand why the plunger would be restricted by some vacuum, with the fluid not freely flowing into the plunger cavity on the upstroke. Perhaps the passage is partially blocked? I also don't see what mechanism then would operate to seal the plunger cavity at the beginning of the down stroke to direct the fluid to the ram. Should be some ball?? I then assume that the fluid should be pressurized to flow to one of the working valve balls, unseat the ball, pass thru to the ram and have the ball reseal on the next plunger upstroke. The teeter totter action would mean that the ball unseated under the plunger pressure is not sealing upon the commencement of the plunger up stroke. I wonder if there are any schematics showing the fluid passages and the operation of the plunger, balls and ram??
So I have to open up the working valve and see if there is any debris in the ball seats or if the ball/balls may be distorted, worn or damaged.
I took some photos of the jack stuff, but I don't see any way to upload. As I remember being on forums years and years ago you have to host the images somewhere to get a url for the forum software to find and display. There is no means of direct upload, correct?





