Viton GLT O-rings

[DanH]

Everyone knows about the Viton o-ring replacement option to allow Cleveland calipers to withstand higher temperatures without leakage. Recall you can use ordinary red hydraulic fluids with Viton, MIL-H5605 (standard) or MIL-H83282 (high temperature), thus it is an easy seal swap.

The only issue with standard Viton has been a slightly reduced low temperature limit as compared to nitrile o-rings. A standard Viton o-ring isn't as flexible as nitrile rubber at very low temperatures.

Today I was poking around and ran across a source for Viton o-rings in "GLT" compound. GLT was developed to address the low end temperature limitation, and is rated -40C to +200C.

Never can tell when you might fly the Arctic, so here's the source:

http://www.oringsusa.com/catalog/index.php

In the "Military and Aerospace" block click "Military Viton GLT", then scroll to "M83485/1-218", which should fit the Cleveland caliper.

[RV6_flyer]

Originally Posted by DanH

Everyone knows about the Viton o-ring replacement option to allow Cleveland calipers to withstand higher temperatures without leakage. Recall you can use ordinary red hydraulic fluids with Viton, MIL-H5605 (standard) or MIL-H83282 (high temperature), thus it is an easy seal swap.

The only issue with standard Viton has been a slightly reduced low temperature limit as compared to nitrile o-rings. A standard Viton o-ring isn't as flexible as nitrile rubber at very low temperatures.

Today I was poking around and ran across a source for Viton o-rings in "GLT" compound. GLT was developed to address the low end temperature limitation, and is rated -40C to +200C.

Never can tell when you might fly the Arctic, so here's the source:

http://www.oringsusa.com/catalog/index.php

In the "Military and Aerospace" block click "Military Viton GLT", then scroll to "M83485/1-218", which should fit the Cleveland caliper.

So what is the lower temperature limit of the standard Viton O-Rings that many people (including myself) are using?

[DanH]

Originally Posted by RV6_flyer

So what is the lower temperature limit of the standard Viton O-Rings that many people (including myself) are using?

About -15C seems typical. There are many different DuPont Viton compounds with a wide range in performance, plus fluorocarbon rubber from other sources, so "standard" is hard to pin down. The range for all compounds is roughly 0 to -65C.

[RV6_flyer]

Originally Posted by DanH

About -15C seems typical. There are many different DuPont Viton compounds with a wide range in performance, plus fluorocarbon rubber from other sources, so "standard" is hard to pin down. The range for all compounds is roughly 0 to -65C.

Thanks. I am retiring and moving to a COLD climate (SouthWestern Pennsylvania) this year. This has me second guessing my choice of Viton O-Rings. I know that the standard MS O-Rings will last 1,000 hours or 5-years which ever comes first based on my last 16-years of RV flying.

[Vac]

Viton-A conforms to Mil-R-83248 and is rated to -15 deg F. Viton GLT conforms to Mil-R-83485 and is rated to -31 deg F.

Cheers,

Vac

[deek]

For those using DOT 5 (not DOT5.1) brake fluid 70 shore fluorosilicone O-rings work well in the Cleveland calipers. I just swapped out new ones after 16 years of service just to see how they looked - they looked as good as the day I installed them.

Again, fluorosilicone is not compatible with MIL H-5605

[DanH]

Originally Posted by deek

For those using DOT 5 (not DOT5.1) brake fluid 70 shore fluorosilicone O-rings work well in the Cleveland calipers. I just swapped out new ones after 16 years of service just to see how they looked - they looked as good as the day I installed them. Again, fluorosilicone is not compatible with MIL H-5605

Good thing we're NOT talking about fluorosilicone o-ring compounds in this thread...or DOT5 silicone brake fluid for that matter.

[Mike S]

Originally Posted by DanH

In the "Military and Aerospace" block click "Military Viton GLT", then scroll to "M83485/1-218", which should fit the Cleveland caliper.

These are too small for the RV 10.

M83485/1-224 appears to be correct size for the 10.

[DanH]

Originally Posted by Mike S

These are too small for the RV 10. M83485/1-224 appears to be correct size for the 10.

Oops, forgot about 10's. Bigger brakes. Sorry.

Update: Yesterday I got an order confirmation, but today I got an email saying the -218 size would require a 300 piece minimum order. I called. They claim to be out of stock, despite showing 296 in stock on the order page.

So much for ORingsUSA.com. Sorry again!

[JoeBlank]

Originally Posted by DanH

Oops, forgot about 10's. Bigger brakes. Sorry.

Update: Yesterday I got an order confirmation, but today I got an email saying the -218 size would require a 300 piece minimum order. I called. They claim to be out of stock, despite showing 296 in stock on the order page.

So much for that source. Sorry again!

Dan,

Try these guys. I was able to buy small quantities from them.

Ace Seal Inc. www.aceseal.com

Also here is some data on the Viton Seals for the 2-place RV brake systems. I've only got the PN for the 2-place listed here but not sure if it is current info with Ace.

? 2-place aircraft calipers:
2-222 (Matco- WHLWE51)
2-218V-75 (Cleveland)