Okay. I’m not too familiar with hydraulic chair designs, but could it possibly take more fluid? One reason that multiple pumps may be required to move it could be related to the compressibility of air versus hydraulic fluid. Is it possible that bubbles could be trapped in the fluid? I’m not sure how to bleed them out if that is the case.
I second raindogs advice. Your system must be vented for it to leak out, however some closed systems are affected by overfill in the same way you describe.
Also you may have a difficult time bleeding the air out of your chair depending on how it is plumbed.
It sounds like you are close to having enough oil in the system but I would suggest adding small amounts and test each time. Lower the chair competly each time to purge air.
Well, that is exactly what I did last night. I added 100 ml at a time, raising/lowering after each addition. After adding about half of the second quart the chair is working better than it was prior to the fluid leaking out!
OK, I got an authoritative answer from a guy at Ritter Dental (the company that made the chair and is still in business). I had originally contacted the company with my problem, but got “Gee, no idea” as a reply.
Well, Rick at Ritter continued researching. He found a manual for a different chair, but they both used the same base. The answer is 2 quarts. I added the remainder of the second quart and I’m set! Plus, I have a PDF of the manual from the other chair.
We have a 20s Ritter dental chair made in England.
We have been using it for a year just fine since buying it. Then all of a sudden after you pump it it slowly goes down little by little…not super noticeable but nonetheless it ends up down to its lowest level within 20 mintes or so…We assumed it was a problem with the oil levels…that it needed a refill basically as we didnt do so when we bought it as it was working great…
So we have taken it apart down to the basin where all of the oil is…
There is a ridge where the mechanism sits…
We dont know how high the oil level has to be though? Anyone have any clues?
ALso, we were told to use hydraulic oil but it seems by what i have read that in fact motor oil is best? Thanks from the Artefacto Crew
This was a few years ago, but I contacted Ritter via email. Nobody could help me until some guy “Rick” came through. When I get to work, I’ll search the computer there. I think I still have the info he sent me.
Know anyone in western PA? Walt at ElectricLine? Rock? Moose (Bob Retter, RIP)?
ETA: I see you’re in London. My best to the Queen!
I tried ringing him butno answer and will try email now.
We put in the 10w Hydraulic oil after emptying and cleaning the pan at bottom of our chair (1920 something Ritten Dental chair) and have pumped up and down a few times and now have it up to see if it is going down slowly on its own like it was before. SO far, fingers crossed, it is not going slowly down on its own so maybe that change of oil and taking it apart and putting it back together again etc… did the trick!Nevertheless its frustrating not having a manual! we have had to experiment with both of our antique dental chairs to see what levers did what! SLightly scary! lol!
Would love to say hi to the queen but im afraid we dont know her…and are defo not royalists…though she is harmful enough i guess.
my husband is from Brooklyn and I am half spanish half english but raised half my life stateside.half my life in spain…so we are foreigners here really Thanks for the advice and if you could send something re. the pdf of what Rick sent you that would be fab! I hope youre having a good day. best wishes from Artefacto Tattoo