Re: Varieze Brake Bleeding


Todd DeVito
 

I just received my bleed nipples from Aircraft Spruce and having never plumbed a brake system before, I'm going to ask a couple of simple questions before I do something stupid.

The bleed nipples I received have about twice as much thread as the plugs that were in the hole.  I'm guessing I should just screw them in until they are tight, even if threads are still showing.  Is that right?

Also, is it a good idea or a bad idea to wrap the threads in teflon tape before I screw them in?

As always, thanks for your help.

Todd

On Friday, August 21, 2020, 03:17:56 AM PDT, Mike Tooze via groups.io <miketooze@...> wrote:


Hi Todd,

Just to clear up from my original post.
Gary Hunter is right in that the original Rosenham axles were aluminium; this was widely reported at the time. I purchased a set of steel replacements, but didn’t fit them quite in time as I had an axle fail a week or two after I received the new ones!
I didn’t raise the condition of the discs in your photo as they appeared to me to be covered in some sort of preservative grease/wax etc. Simply clean and assess their condition. As long as they are in plain, flat, and not too worn, thin, a few pits won’t matter.
Certainly everything needs disassembly for a good clean-up and inspection but ‘if it works don’t fix it’.
Yes, you will need those cap screws, bleed nipple, and the heat barrier (aluminized blanket, non-asbestos hi temp silicone and/or wired in place). However, change for change sake is not particularly a philosophy I would back. Few of us are in that position.
I test flew my Vari in 1982 and we are still flying, Nylo Seal and all. (I’m on the steel axles and my second set of Matco discs.) My runway limit, around SL to 2k’, is about 600m/2,000ft but I use far less.

BTW your tires appear to be the 3.40x 3.00x5 Shins, which I use. What with these and the Matco’s you have the possibility of making a sleek set of wheel pants, not like the balloons seen on so many Ezes. ;^)
I suggest that you try what you have before splashing out just because of a bit of age-accumulated dirt.
If it taxis well and you run-in a set of new pads ok, then you’re set to go.
We’d all be interested in a report back.

Mike Tooze
O-235 Vari Eze
Amongst other things I’ll be checking my tyre pressures at the weekend so will try to take a photo of my set-up.





------ Original Message ------
From: "Todd DeVito via groups.io" <devitotl@...>
To: "canard-aviators@canardzone.groups.io" <canard-aviators@canardzone.groups.io>
Sent: Friday, 21 Aug, 20 At 02:55
Subject: Re: [c-a] Varieze Brake Bleeding

Thanks to everyone for the great responses. It's great to know the brand of calipers I have, and even better that you passed along the part number for the bleeder assembly and pads. It's also good to know about the possible axle issues. I'll be searching the CPs and CSA newsletters for information about Rosenhan brakes.

I will also be searching the CPs and CSA newsletters for information on installing a thermal shield. I have seen some stories about the consequences of not having one, but have not looked into building one yet.

Interestingly, the brown on the brake disc is not corrosion. It is some sticky, tar like substance. Once I'm sure the system holds fluid, I'll have to take the brakes apart and clean all of that gunk off and also see if the pads are contaminated.

Thanks also for the Grove ordering information. Depending on how these brakes perform, I may go in that direction.

I have also wondered if the tires on this plane are adequate. I do not like the idea of landing on tires that are not appropriate for the purpose. Before I bring my Eze to the hangar for it's first test drive, I'll make sure it has the correct tires.

Finally, if anyone has a picture of this model of brakes on their Eze, I would love to see a copy.

Thanks again for all the information.

Todd

On Thursday, August 20, 2020, 03:47:28 AM PDT, Mike Tooze via groups.io <miketooze@...> wrote:


Hi Todd,


From your picture I would say that your brake assembly is an Rosenham, became Matco, the same as I have on my Vari Eze.

What you may need is an ACS p/n 11225 Brake Bleeder Assembly, it just screws into the hole in the bottom of the caliper.


Other comments. The disk normally has three counter bored holes for three hex cap screws, wire locked to wiring holes in the disk, just visible in your pici. Therefore those existing bolts should come out and be replaced by caps screws. (See ACS 'socket head cap screw alloy steel-drilled, coarse thread'.). You may find that the counter bores for the cap screws are on the other side of the disc as fitted, in which case you will need to reverse the disc.

A reflective heat shield between the disc and gear leg is essential; also I wrap my Nylo Seal tubing and fittings with the same heat reflective/insulative material.

If/when you replace the pads, RA66-106-4K brake kit, you will have to order additional 1/8” by 3/8” long brake pad rivets as the rivets in the kit are for Cleveland and too short.

I use DOT5 brake fluid but ensure that it only ever touches the inside of your brake system/tubing. i.e. Never, anywhere, on your Eze or even in your workshop!


I have found that my brakes perfectly sufficient for my Vari Eze. (I use 'dynamic braking', nose wheel 'off' till the last moment without banging it down.)

Just what I have/do - OMV.


All the very best for your project.

Sincerely,

Mike Tooze

O-235 Vari Eze







------ Original Message ------
From: "Todd DeVito via groups.io" <devitotl@...>
To: "Canard Aviators" <canard-aviators@canardzone.groups.io>
Sent: Thursday, 20 Aug, 20 At 03:00
Subject: [c-a] Varieze Brake Bleeding

Hello Everyone,

This is a picture of the left wheel and brake on my Varieze project. The problem is I can't see a nipple to bleed it with. Is anyone familiar with this type of caliper and can you fill me in on how to bleed it? On the bottom right of the caliper is an allen head screw. When I removed the screw and used a mirror to look into the hole, it leads into the bottom of the caliper, but there was no nipple attached.

I didn't find any names or part numbers on the brake caliper, but the master cylinder is a Grove part #675-3, manufactured in 12/06.

Thanks for any help you can offer.

Todd DeVito






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