Given the number of threads about leaking pedestal o-rings, I have been doing some research on what are hopefully better solutions. It seems one such solution is the quad-seal/x-seal/quad-ring/x-ring. I am not a seal engineer so I am throwing this out there for discussion. What do you think?

I have found the appropriate replacements as well:

 

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I tell you what Leonard...

I have replaced my pedestal o-rings (all of them) three times now and each time at least one of the lower ones has started to leak after about a year of being in service. These were always the "quality" o-rings from Riffraff and Diesel-O-Rings as well, not some Ace Hardware specialty. I am starting to think there is an imperfection in the lower seat on the block or something. I have used engine assembly lube in order to ensure they stay where they are supposed to be as well. The T4 pedestal from CSD only uses the two lower o-rings, but again after about a year at least one is leaking. It is a very slow leak and over 5000 miles of driving/towing I cannot see any visible movement on the dipstick, which is a good thing.

Anyway, I am looking forward to what you find and if I ever take the T4 pedestal off for any reason, I will most certainly be looking for another set of o-rings to try.

 

One other o-ring characteristic which we cannot overlook is its durometer hardness. This became especially to me recently as I ordered some "upgrade" Viton o-rings for the new (waiting to be installed) IH water pump shut off valve. I incorrectly chose 90 durometer o-rings, and it turns out to be too hard and stiff to stretch over the valve shaft, and they simply will not work. I've now already received the 70 durometer Viton o-rings which are more pliable and will work.

My point is this. The 90 durometer Viton o-rings may well be a workable "upgrade" for the turbo pedestal location because they do not need to stretch, and the harder material will require more pressure to compress them into position. That additional compression pressure may just be the ticket to letting the conventional o-ring design survive for longer periods of time. Perhaps, though, someone has already tested this option and deemed it "not helpful". I'm just spit balling the idea.

EDIT -- FWIW, the pedestal o-rings I installed when I did my EBPV delete (5 years ago) have held up well. At least, I think they have held up well (I do have a weeping oil leak right now and have not yet chased down the source... just keep slipping the cardboard under the truck every night to keep from staining our driveway. If is is the pedestal o-rings, then I got a little over 3-1/2 years out of them because the oozing started about 7 months ago, and the 4-yr mark was in mid January this year.

Regarding the quad o-ring design, I really like the concept! By it's very geometry, it provides a double seal point wherever it contacts either a moving or stable surface!

 

I like Pete's suggestion of the increased durometer. The quad o-ring is more for a dynamic seal...McMaster has a square profile (whether it is available in Viton or the the size remains to be seen) that might have possibilities.

 

Alternatively, you can get 75D Viton quad rings for about $10 each.
Just sayin'.




If I end up tracing my leak to the pedestal, I'll bite on the quad Viton configuration and see how that goes.

 

He can get a bag of ten, in 90D, of the 205, Viton at McMaster. for $5.50 and the ride.

 

The ones suplied in the SPT kit's are still good after 3 years and + on some of the work trucks. Are you sure you guys are tightening the pedestal bolts tight? After years of mechanic work my hands develop a sense of correct torque for any application. Maybe you guys just need to tighten the bolts more than the specified torque spec.

 

I tightened mine like they hold the oil pan on....no leaks.

 

I had not even thought about the hardness of the o-ring. So you guys think harder is better? (let's head off any "That's what she said" jokes right here, okay? )

 

For the static and stationary load conditions in the pedestal application, I tend to believe that a denser o-ring would not compromise anything, and may improve the sealing effect from a higher contact pressure (due to the o-ring's increased resistance to deformation). If the o-ring were in contact with a moving surface, though, any increased brittleness associated with a denser o-ring material could very create a liability.

Whew! Leonard, it's challenging to avoid words and phrases which could incite comments akin to your "to be avoided" topic mentioned above, but I think I managed it.

 

It's a good thing you did you young 'un you. Us curmudgeonly types are easily offended.

 

I found some handy information on o-ring hardness. It seems sticking to between 70 to 80 Shore A is the way to go.

https://promo.parker.com/promotionsi...ehome/Hardness
https://www.globaloring.com/durometer/

 

Young 'un? Me? I fast catching up to the curmudgeon status. My wife even tells me sometimes that I'm way too quickly becoming "just an old man".

 

Well, since I'm replacing my HPOP lines and fittings this weekend, I think I'll go ahead and replace the pedestal o-rings at the same time just to knock out a few more potential leak points (for now). That said, I just ordered the Viton quad rings linked about, so I'll be the guinea pig on this one, see how they work out, and then report back on my impressions.

 

Sounds good. I'll probably go with the 75D ones as well when I get to swapping to the T4 pedestal.