I am in the process of restoring my grandfather’s Ritter Dental Chair which he used from the early 20’s (chair is prior to the model “B” chair) his death in 1976. It has been in storage since his death. I am having trouble with the hydraulic cylinder, patent drawings and description link attached. The cylinder raised and lowered when it went in to storage but now there is no resistance in the raising pedal. I was wondering if there is anyone who knows how or anyone who I can be referred to that can help me get it working again. I have emptied the hydraulic fluid and added a quart back but not sure if this is the correct amount or was added properly. The chair has no electric component to it. Thanks for any help you can offer
I have a Ritter chair. When I moved the chair and some hydraulic fluid leaked, I searched for information and started a thread here (although I called it a barber chair).
Here is a PDF of a manual for the model B chair, in case it helps.
Yes. Your past problem is what brought me to this site. Unfortunately Rich Schrader’s e-mail address is no longer valid. My chair is the model before the model “B” and is all hydraulic. My chair does not raise at all although it did before going into storage. No resistance on the raising pedal Not sure whether its mechanical or a fluid problem. Reluctant to disassemble unless I have to. Though someone might be able to look at the patent drawings and give me some ideas. Thanks for the response
I just got done restoring a vintage beauty parlor chair with manual hydraulic lift. Fortunately the hydraulic works. But if there is no resistance I would first suspect the pump seals or check valve are allowing fluid to blow by. Another reason might be the release valve which is activated by pressing the pump arm all the way down but I would not expect it to stick open without being stored that way.
If the main piston seals were bad then oil should leak out every time you pump it.
The pump should be easier to get at, on the chair I have it has a short shaft sticking out that gets pressed by the foot pedal. There is a threaded collar that the shaft comes through and it can be unscrewed. The pump shaft and piston should pull out.
If you get that far you might look up automotive floor jack rebuilders in your area for suggestions on parts. It probably uses leather cup seals instead of O rings.
Dennis
Try contacting a Dental Supply company.
A good repairman may well be able to help.
Thanks I will give that a try
Everything mixdenny said plus check that the release valve isn’t open or stuck open.
Hello Do you have a current link on the manual for the ritter barber chair mdel B?
not sure if anything in this link will apply, but it’s got a lot of hydraulic jack overhaul info from a guy that knows what he’s doing
I’ve got a Koken barber chair, and it’s been quite a project to track down replacements for some broken parts. Mostly in the form of “What’s this whatchamahickie called?”
The good news is that hydraulic dental and barber chairs are more or less universal in how they work, so googling “hydraulic chair won’t go up” or “hydraulic chair no resistance” should eventually get you in the general direction. Amazingly, Ritter Dental is still in business, so it’s a long shot, but they may still have info in their archives. Hopefully it wasn’t deleted when Rick left.
If pressing the pedal or pulling the handle has no resistance and you don’t hear any sucking/gurgling noises at all, the pump seal is either completely gone, or rust/gunk have conspired to keep the cylinder in “lower the seat” mode. It’s all 18th century technology, so for the most part, things that look like they should move, should move. 