The International Cessna^® 170 Association

Need help from anybody with 8.00 or 8.50’s. I just put some 8.00 X 6 on my A model and I am now having a break fit issue. I have stock gear with single puck Cleveland’s. When I put the new tires on the break caliper now is within a 16th of an inch from the tire. My fear is that on landing the tire will flex and rub the caliper. Has anyone run into this with the bigger tires if so what did you do to correct it? I was thinking about a spacer to move the break disk out away from the wheel half.

My Cleveland double pucks have quite a bit more clearance than that with the 800x6 tires. You might want to check and see if your wheel/rotor combination is correct. This site might help if you don't already have it, I replaced my rotors last year due to pitting and now that I think about it I was unable to find a part number on the old rotors.
http://www.parker.com/ag/wbd/Cleveland/pdf/wb01.pdf

Cleveland (Wag Aero) sells a spacer that will increase the clearance. A few years ago I had a Super Cub with 30" Airstreaks. The tires rubbed on the double puck back plates (the plates that hold the outboard pads) even with the spacer. There is a lot of extra material on the outboard edge of the back plates and I ground off about 1/8" worth of clearance where it was touching the tire. It didn't take much. I did not grind off so much that it got into the mating surface area with the caliper. I flew the Cub several years all over Alaska onto gravel bars, rough tundra, and steeply inclined beaches. It never had another problem with the tire touching and it did not affect the integrity or function of the brakes whatsoever. Letting it rub on the tire will definitely affect safety.

A spacer is produced for this problem. A friend bought me a set at a store on Merril Field (sp) in Anchorage, AK. Maule also used to have them.

Call Bill at Stoddard's in Anchorage, 907-272-2327 for the spacer if it is more convenient than calling Wag Aero.
Richard

Thanks, I will call them. I think that I will end up upgrading to the double puck 180 breaks and wheels.

What I ended up finding out is I have the wrong wheel assemblies for the 170 and that is why I had such a bad fit. So that leaves me with either purchasing the correct wheel and break kit and the spacer, or getting the 180 kit that was made for the larger tires. In any case I am buying new wheels.

Just be aware that any changes to brakes, tires, wheels may involve getting a new basis of approval, even if all you're doing is adding spacers...they should have a basis.

I am in the middle of my annual right now, I decided to replace the aluminum hollow axles with the steel axles from Airframes Inc. I am also upgrading to 8.00s and have the same problem as everyone else with the sidewall clearance. I was looking for spacers when I came across Cleveland's Product Reference Memo (PRM 26) for installing 8.00's with clevelands. It basically says to use 1 each per bolt 095-00800 washers radiused surface down towards wheel (beneath the brake disc assembly), discard the standard AN5-35A tie bolts, and use AN5-36A tie bolts with AN365-524 nuts and AN960-516 washers. Sounds like a simple fix as opposed to trying to find or manufacture a spacer.
David

Thanks for the fix Bruce. Message edited.
David

David

Look at your post in the upper right corner when you are logged on to the forum. There will be a little edit button. Clicking this will allow you to edit your post.

Bill Hart wrote:Need help from anybody with 8.00 or 8.50’s. I just put some 8.00 X 6 on my A model and I am now having a break fit issue. I have stock gear with single puck Cleveland’s. When I put the new tires on the break caliper now is within a 16th of an inch from the tire. My fear is that on landing the tire will flex and rub the caliper. Has anyone run into this with the bigger tires if so what did you do to correct it? I was thinking about a spacer to move the break disk out away from the wheel half.

I just reviewed the Cleveland (Parker Hannifin) technical manual. They have a product reference memo regarding this issue. PRM 26. It addresses the issue of tire side wall rubbing on the brake caliper. It refers to the issue as installed on Mauls. It has adrawing with the PRM

If you look at the product catalog for the Maul and compare it to the kit directory for the Cessna 170 which incidentally only allows single puck brakes on there STC for the 170 models. You will find that the parts list for the Maul wheels 40-97D and the parts list for the Cessna wheel 40-97A both have the same parts included in the make up of the wheel. As well the brake caliper part number 30-63E & 30-63F used on the Maul have the same parts break down as for the Cessna 170 series 30-63A.

The Parker Hannifin PRM 26 outlines installing 3 ea 095-0080 washers along with longer bolts under the disc to preclude this issue. I have done it in the past on Mauls. However this is not approval for doing the same thing on the Cessna wheel and brake assembly because the PRM does not address the issue for the installation on 170’s. Even though the assembly and issue is the same.

Call Parker Hannifin they are sometimes quite helpful. I have addressed this issue in other ways on other aircraft. All of which I own or operate.