• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!

    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Healey Overdrive Accumulator Piston using O-Ring Seal Up-date Feedback

mwagon

Jedi Hopeful
Country flag
Offline
Healey Overdrive Accumulator Piston using O-Ring Seal Update Feedback

In the process of rebuilding the O/D & noticed that AH Spares offers an updated Accumulator & Piston that uses a Rubber O-Ring on the Pistion, instead of the original design that uses a metal Pistion Rings. I don't see any other supplier selling this yet, but wondered if anyone has tryed this setup yet. I like the idea of eliminating the metal Piston Rings. The originals last a long time , but steel rings on an Alu. Accumulator never seemed right to me. Seems like it would minimze wear on the accumulator, similar to the Operating Piston arrangement
 
Re: Healey Overdrive Accumulator Piston using O-Ring Seal Update Feedback

I could be mistaken (it happens...) but seems like the later Healeys, certainly the units fitted to MGBs had switched from cast-steel rings to rubber O-rings, so you really won't be blazing a trail__which is to say that they're proven/accepted.

Likewise, the operating pistons on the later Healeys (and ALL MGBs, regardless of ovd type) used O-rings too, if you're so inclined to swap out these pistons.

Not to mention, the O-rings cost a minute amount compared to the cast rings!
 
Re: Healey Overdrive Accumulator Piston using O-Ring Seal Update Feedback

[edit- updated info, thanks Randy.]

I left mine as-is on the basis that the accumulator piston is also the pressure regulation valve and I felt that having an oring constantly crossing over the spill ports at 400-odd psi would shorten it's life greatly. The later design with oring seal used different size holes for the spill ports I think. Definitely good to replace the apply piston rings with orings. Andy.
 
Last edited:
Re: Healey Overdrive Accumulator Piston using O-Ring Seal Update Feedback

Steel piston

IMG_3015.jpg


IMG_3017.jpg


Aluminum sleeve

IMG_3029.jpg


IMG_3033.jpg


IMG_3034.jpg


IMG_3037.jpg
 
Re: Healey Overdrive Accumulator Piston using O-Ring Seal Update Feedback

The same pieces, save for new cast rings and O-rings, but with a dry-film polymer coating added.

IMG_7110.jpg
 
Back
Top