What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

SL-00047 Brake fluid and O-ring

plehrke

Well Known Member
Patron
SL-00047 O-ring availability

Anybody recently ordered and/or received the U-00015-1 Brake Caliper O-ring kit from Vans? They are still showing up as back ordered.
Anybody find the -40F to 400F Viton ones that Vans sells from a different source? I have read all the threads on Granger, o-ring store, or McMaster Carr ones that are -10 F to 400F but i want the GLT V1038 compound that goes to -40F if I can get them in a reasonable time.
 
Last edited:
O rings backordered....

Anybody recently ordered and/or received the U-00015-1 Brake Caliper O-ring kit from Vans? They are still showing up as back ordered.
Anybody find the -40F to 400F Viton ones that Vans sells from a different source? I have read all the threads on Granger, o-ring store, or McMaster Carr ones that are -10 F to 400F but i want the GLT V1038 compound that goes to -40F if I can get them in a reasonable time.

I had an order from Vans that was being held up for those "O" rings being backordered. I finally asked they send the remainder of the order and leave those off. The order should arrive this afternoon....

I have been wondering why we need "O" rings that are rated at -40 to+500 which seems plenty of range for me. I will probably not be flying in that temperature, even at altitude. Most that I have found online go to -15 which seems like plenty cold. Reasoning?:confused: Curious minds want to know.....:cool:
 
Just talked to Vans a few minutes ago. They say the o-rings are back ordered to at least the end of March before they ship. I will probably order the -15F ones from McMaster Carr or Marco Rubber.
 
Last edited:
"O" ring temperature debates....and Winter flying.....

Same here (in Virginia), but I flew winters in MN/WI/MI and very sad to say it gets lower than -15 there.

I always love the question from my non-flying friends/acquaintances who ask "Do you fly in the Winter?". My standard answer is: Yes; there is air in the Winter!:p That being said, I do have my limits. Especially in the (drafty ?heater) Cub. Much easier in SuzieQ but still, less than -10 F I am perhaps going to be making my "next project" list in front of the pellet stove. ;)

OK: it seems the "O" rings from Vans are being crafted from unobtainium. I ordered mine in January and they were on backorder. Now it will be at least the end of this month. I need to get my brakes overhauled (with new hoses :)) and the new fluid in before Spring Flying Weather arrives! I have an order from McMaster-Carr pending for the -15-+500 rings. And I was thinking as I woke up this morning (when I do my best thinking, sometimes!:rolleyes:) that I would rather have the +500 degree protection than the -40 degree protection as the brakes being subjected to high temperatures is WAY more likely than -40. Have you ever touched the brake rotors after some heavy beaking? :eek::eek: HOT! There have been several reports of brake fires for that very reason. I find it odd that the recommendation is for the higher temperature 782 brake fluid that will withstand higher brake temperatures but being concerned about having a ring that will tolerate -40F. :confused: This is what I get for thinking just as I wake up.....:D
 
Current O-rings

Just to document somewhere, since I have not seen it in any of the SL-00047 threads yet, the current o-rings that come in the Cleveland brake calipers are good for -65F to 275F (MS28775). I am not sure I am comfortable with reduced low temp capability of the Viton ones from McMaster-Carr (-15F to 400F) and most likely wait for the back ordered GLT Viton o-rings (-40F to 400F) from Van’s. I ordered both so will see if I can wait for the ones on back order since my brakes are already apart and drained of fluid.

Cleveland brake application chart

30-9 Cleveland brake exploded view.

O-ring properties

Since I have Cleveland brakes I have not looked into what are the current properties of the o-rings supplied by Matco.
 
Last edited:
ANYBODY know when Vans is going to start shipping the U-00015-1 orings? I have several RVs that I maintain and Vans seems to have these bankordered indefinitely..
 
Unobtanium "O" rings.....

ANYBODY know when Vans is going to start shipping the U-00015-1 orings? I have several RVs that I maintain and Vans seems to have these bankordered indefinitely..

I have seen the Van's recommendation for the "O" rings with the lower temperature tolerance but have not seen the rational for that recommendation. Did I miss something? Curious minds want to know. I still contend that I would want to have a material that tolerates higher temperatures as that is more likely to be what the brake calipers will be subjected to.

My McMaster "O" rings just arrived so I will start my brake system overhaul as soon as I move to the next item on my list. I also ordered fire-resistant grommets that have already replaced the black ones in the firewall fittings that were not fire-resistant for electrical wire penetration. Something in my wondering mind wants to subject both to a little heat and see how they fare.......:eek:
 
I have seen the Van's recommendation for the "O" rings with the lower temperature tolerance but have not seen the rational for that recommendation. Did I miss something? Curious minds want to know.

My rational:

Original Cleveland are good to -65F
McMaster Carr Viton are good to -15F
Vans GLT Viton in U-00015 are good to -40F

I take off in winter at 15 to 20F often. Std temp lapse rate makes that approx -10F at 8,000ft. An hour there will have cold soaked the calipers and O-ring to -10F or -15F. I land and touch brakes and o-ring is cold and hard. Sure, once brake pads start touching you get a bunch of heat but maybe a bunch of fluid has already squirted past the hard o-ring.

YMMV if you never fly in cold weather.
 
Last edited:
It says not compatible with brake fluid? What oil is everyone using with these O rings

There are several major types of "brake fluid". Most autos use DOT3 type, which is based on glycol ethers - and these require EPDM. Aircraft "brake fluid" is oil-based, and happy with Viton.

Lots of good info here:

https://www.theoringstore.com/store/index.php?main_page=page_3

If you scroll through the details of that list you will start to get a feeling for the type of material that is compatible with various liquids.
 
Back
Top