New brake shoes too tight on 185s

[webbch]

I'm putting on new rear brake shoes on my '83 185s, and they are VERY tight. The old ones were severely corroded - the tab holding one of the springs on actually broke and locked up the wheel. It was a very quick breakdown - The brakes hadn't been overly tight before that point. I took it apart and bead blasted the drum, then washed and put a light coat of paint (not on the braking surface) to avoid future rust, removed the brake arm pivot and cleaned everything up and lubricated the pivot points before installing new Honda OEM shoes. There doesn't seem to be any kind of a ridge on the lip of the drum, although I sanded it a bit by hand to prep it for the new shoes.

The drum was VERY tight going back on, but only on the upper pad. Once I got it on, I started the motor and ran it up on blocks for a minute or 2 to hopefully wear them in, but there is still NO play on the brake arm (haven't even attached the brake cables yet), and of course the drum gets smoking hot. When I rotate the axle by hand, it's pretty constant friction all the way around (to alleviate concern of a bent axle or egg-shaped drum). The shoes looked perfectly symmetric, but I'll try flipping them over and re-installing to see if it changes anything. I put them side by side with the old shoes and it looks like a perfect match, so I'm pretty confident they're the right shoes.

Any idea what could be happening? Anybody else have to sand down their brand new Honda OEM shoes to get them installed?

[barnett468]

if your brake actuator moves freely then the shoes are too thick no matter what they "look" like. they are not orig honda shoes are they?

you can sand them with 180 wrapped around a wide flat file but that's hokey. after sanding install them and run it for a few minutes using the brake on occasion. remove shoes and sand the shiny spots only. they are the high spots.

good luck.

[webbch]

I happen to be replacing the rear shoes on my '84 200s right now as well. They're not in that bad of shape, but I was doing R&R because the brake cam was getting sticky. The new shoes (same P/N as the 185) fit great on it. Drum slides right back on with no effort.

With that said, I verified the P/N for the brake shoes are identical for both my '84 200s and '83 185s. I tried putting the worn shoes from the 200 onto the 185, and had the same problem with the drum hanging up on the top shoe on the 185, although I _could_ run it without excessive heat at least. It was definitely tighter than the 200 with the new pads. It's not a ridge on the lip of the drum either - If I run it it creates wear marks all the way across the surface of the top shoe. At this point, I don't see how it could be a problem with the shoes themselves, given that I've tried both a new set as well as an identical worn set, and worn set is "barely" loose enough to be usable.

I've also tried swapping the drums between the 185 and 200, since they are identical as well. No improvement.

At this point, the only conclusion I can draw is that somehow the assembly that the brake shoe hardware fits into is a bit off center relative to the axle. The only way I can think to fix it is to move the stationary pin that the brake shoes pivot on down a little bit, which would require me to drill out some rivets and then weld it back in place.

[webbch]

That's not a bad idea. I may try that option on the worn shoes to see how much it can buy me. If that doesn't get me where I need to be, used rear carriers are more reasonably priced than I thought as well, although I'd need to factor in the cost of new wheel bearings and seals most likely.

[barnett468]

To confirm your theory, I would put the top shoe on the bottom. If the top shoe still hangs up, something is off for sure. If the bottom shoe hangs up instead, then it is the shoes that are the prob.

I might also exchange the axle carrier or axle if I was motivated and if they interchanged but that's a bit of work.

The most likely thing that could be off other than the shoes, is the fixed pin on the axle carrier as you are thinking. Trying to relocate the fixed pin in exactly the right place is challenging. If the pin is in the wrong place I would simply sand the shoes as I suggested. They will work PERFECTLY.

You can try grinding the half curve as suggested however I would NOT do this. It is a bit hard to grind/file it exactly 90 degrees to the shoe or the other end.

Also, if your shoe you use is not the correct arc, it will not stop great even after grinding the half curve. If you sand it exactly as I suggested, you will arc the shoe to the drum. I have done this a zillion times. Yes, a zillion.

If in fact the fixed pin on the carrier is off, once the shoes are arced the improperly located pin will have no affect on braking performance.

If those are real Honda shoes then either the pin got bent somehow AFTER the bike was delivered or the shoes are NOT the exact same size they were back in 83. That bike NEVER would have gotten far from the selling dealer without there being some sort of repair done to correct the prob you are having.



Are they made by Honda?

Did they come in a Honda package with a Honda label?

Did the new and the old shoes that you installed on the 185 have a uniform wear mark across the surface on both the top and the bottom shoe etc.?

[just ben]

I m not familiar with this model but every drum set up I have dealt with one shoe is thicker than the other. The thicker shoe goes toward the back of the vehicle.

[webbch]

I m not familiar with this model but every drum set up I have dealt with one shoe is thicker than the other. The thicker shoe goes toward the back of the vehicle.

Is that how the Kawi trikes are then? These Honda trikes (the 3 I have anyway) have shoes on top/bottom, not forward/aft like they are on cars/trucks.

I've tried putting the top shoe on the bottom and bottom shoe on the top - still hangs up on the top one.

They are true Honda shoes. Actually, Honda has an updated part # for the shoes, so I suppose it's "possible" they are slightly different from the original part from the factory. However, it seems like a lot more evidence is pointing at the carrier and/or fixed pin (doesn't appear visibly bent BTW) than at the shoes. I may just use the old shoes from the 200 and be done with it - they probably have at least 60% material remaining on them and are just "barely" loose enough to run on the 185. When I temporarily installed the new shoes and ran them, the contact area was across the entire area of the top shoe.

[barnett468]

ok, thanks for the info. good job on testing. it does seem as though the pin location is incorrect as you suspect.

it is certainly possible that the new part number shoes are thicker than the old ones even though they still fit your 200. some things just don't seem to be what they used too.

it is possible that the brakes were dragging from new and the shop simply ground down the shoes and sent it on its way even though they could have done a warranty carrier exchange on it if that is the prob.

not all shops are created equal, lol.




You can try grinding the half curve as suggestedI agreed that one “can” grind the shoe.




I would NOT do this.I did not use the term harmful. I simply said that I would not do that. Obviously others may. It is highly unlikely that you brakes would fail if you did this.




It is a bit hard to grind/file it exactly 90 degrees to the shoe or the other end.I briefly explained why I would not do it.

:beer

[DohcBikes]

just ben, what model and set of shoes are you referring to?

I know of no model that use two different thicknesses of shoes on the same brake, and I can't imagine why this would ever be the case.

[DohcBikes]

Well, on an automobile, both shoes are operated by the same wheel cylinder. There are no wheel cylinders that I know of with one size bore on one side and a different size bore on the other, therefore, both shoes receive the same amount of pressure.

The automotive shoes i have installed, which is admittedly not many, often have one with a lining that is shorter than the other, but the thickness was the same on both.

[DohcBikes]

Im not convinced El. If someone would give me a specific model and year where the thicknesses are different, I'll take my calipers to the parts store today to check it out.

[TwoBobRob]

I don't have the answer to the original question but I can answer the automotive shoe question...

It's all about leading and trailing brake shoes. Some will be longer, some will have a thicker lining. Some, maybe both depending on design. The principle is (in simple terms) that the shoes bite into the drum when travelling forward to increase the braking effort. One shoe is pushed into the drum and the other is dragged. When travelling forwards that is. Consequently the shoes often wear at different speeds so the manufacturers counteract this by making two different shoes. In these cases, it is crucial that the shoes are fitted in the correct orientation.

This is the reason why your brakes are always worse when you're reversing......

Going back to the original question though, for what it's worth I'd be sanding the high spots off the shoes myself.

[webbch]

Given that my 40% worn 200s shoes are just BARELY loose enough to install to install on the 185s (still less "swing" on the brake arm than the NEW shoes on my 200s), I think I'll take some measurements from the axle to the top of the top shoe and the axle to the bottom of the bottom shoe. The difference between those measurements should tell me just how out of whack things are....

I may be able to split the difference by moving the "fixed" pivot by drilling out the rivets, moving, and then welding it back in place. I may hold off on doing that until I have to replace pads again though. Depends how it feels once I get it back together.

[DohcBikes]

I don't have the answer to the original question but I can answer the automotive shoe question...

It's all about leading and trailing brake shoes. Some will be longer, some will have a thicker lining. Some, maybe both depending on design. The principle is (in simple terms) that the shoes bite into the drum when travelling forward to increase the braking effort. One shoe is pushed into the drum and the other is dragged. When travelling forwards that is. Consequently the shoes often wear at different speeds so the manufacturers counteract this by making two different shoes. In these cases, it is crucial that the shoes are fitted in the correct orientation.

This is the reason why your brakes are always worse when you're reversing.......

And did you have a SPECIFIC model and year of the vehicle that these shoes with different thicknesses are supposedly mounted on? Because that was the only question anyone had. I know how brakes work.

[barnett468]

Given that my 40% worn 200s shoes are just BARELY loose enough to install to install on the 185s (still less "swing" on the brake arm than the NEW shoes on my 200s), I think I'll take some measurements from the axle to the top of the top shoe and the axle to the bottom of the bottom shoe. The difference between those measurements should tell me just how out of whack things are....

I may be able to split the difference by moving the "fixed" pivot by drilling out the rivets, moving, and then welding it back in place. I may hold off on doing that until I have to replace pads again though. Depends how it feels once I get it back together.

well if you have an extremely accurate way of neasuring this it could be done.

the shoe thickness should be within around. .005" of each other and the distance from the axle shoud be that too. you then need to measure the distance of the fixed pin to the axle otherwise the lin might get welded to far forward or rearward.

you then either need the pin height from the ground or simply assemble the shoes on the pin and backing plate and move it around until it is where you need.

[TwoBobRob]

And did you have a SPECIFIC model and year of the vehicle that these shoes with different thicknesses are supposedly mounted on? Because that was the only question anyone had. I know how brakes work.


No, of course I do not have specific model details. I'm merely speaking from 30 years of experience in the motor trade.

You'll just have to trust me.

Or not.

I suspect no one cares.

[webbch]

OK, back to the problem at hand :) .....I figured I'd button it all up and run with the worn shoes...let them wear in and see how things went. Bad choice. I rode around for awhile and all seemed to be going well. Didn't have excessive heat, brakes were working. And then, suddenly they weren't. No rear brakes at all.

I took it apart to find the hub of the brake drum had broken out. Argh!! The hub slid right off the shaft just like you'd expect from freshly grease splines. It was just separated from the drum. Now that I had it apart again, I decided to take a very critical look at it. I took the measurements I had planned on (top of axle to top of a _new_ set of brake shoes, and bottom of axle to bottom of shoes), and there wasn't enough variation for me to think things were drastically out of whack...on the order of about 0.010-0.020".

Then I took a VERY critical look at the pivots that the shoes sit on. The fixed pivot for the brake shoes appears ever so slightly bent. I apparently just didn't notice it before. It certainly isn't extreme in the least; barely noticeable when you're looking for it actually.

I went to ebay to look for a replacement brake drum, and since I could order a rear carrier that included the brake drum for only slightly more than the brake drum by itself, I decided to do so. It just seems like such overkill to replace the carrier due to a bent pivot pin. My gut tells me to heat the pivot and at least TRY to bend it back in place. If that doesn't result in being able to properly set the drum in place with the new shoes installed, then I'll probably just go ahead and replace the carrier and be done with it. I picked up a set of wheel bearings and seals in case I go that route as well. I seem to be amassing a good sized "spare parts bins" with these darn trikes!

[DohcBikes]

No, of course I do not have specific model details. I'm merely speaking from 30 years of experience in the motor trade.

You'll just have to trust me.

Or not.

I suspect no one cares.I care. It pertains to the original question, and id like to clear up any confusion about the thickness of brake shoes.

When it comes to tech info, I trust numbers. Facts. Not people I have never even met or spoken with on a personal level.

Experience is great. Proof is better. I'd like to see a specific set of shoes where one is thicker than the other. So far none of the three people that claim it occurs have provided a specific example in this thread.


Glad you are moving in the right direction webbch.:beer

[just ben]

I'd like to see a specific set of shoes where one is thicker than the other. So far none of the three people that claim it occurs have provided a specific example in this thread.




Type "new brake shoes one is thicker than the other" into google and pick one.

[webbch]

At the risk of continuing the above arguments......

Got it fixed. In the end, I was glad to have ordered a replacement rear carrier and wheel bearings, as that was what it took to get it fixed. The only alternative IMO was drilling out the rivets holding the fixed pivot and then welding it in a new position. The time required to do that compared to the replacement cost of the carrier made for an obvious decision, especially since I'm not a great welder and it likely would've taken some trial/error to get it in the right position. Since the replacement carrier had a bad wheel bearing, I was glad to have replacement bearings and seals on hand. The new(used) drum slide right on with the new brake shoes, and it's riding good now.