A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

1987 Cobra Trailer Brake drum removal



 
 
Thread Tools Display Modes
  #1  
Old June 24th 17, 02:10 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 23
Default 1987 Cobra Trailer Brake drum removal

We have a 1987 Cobra Trailer that had its brakes fried. Crew forgot to release brake. Does anyone know how to remove the brake drum? Newer Cobras have a Allen bolt that when removed the entire assembly come off. This trailer does not have that. Any input is helpful.

Colin Mead
  #2  
Old June 24th 17, 05:23 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 21
Default 1987 Cobra Trailer Brake drum removal

On Friday, June 23, 2017 at 7:10:38 PM UTC-6, wrote:
We have a 1987 Cobra Trailer that had its brakes fried. Crew forgot to release brake. Does anyone know how to remove the brake drum? Newer Cobras have a Allen bolt that when removed the entire assembly come off. This trailer does not have that. Any input is helpful.

Colin Mead


Colin,
What happens when you take the wheel off? I have a later model Cobra and IIRC a 22MM Socket removes the entire axle. Something to remember is that Cobra uses AL-Co running gear so if you can get a manual for this particular year it would help. Another good reference id Alfred Spindelburger at Cobra. Ive done a bit of work on these trailers (More than I care to recall) and Spindleburger (SP?) will occasionally email you back immediately during business hours (They are several hours ahead so try this in the morning). If you pull the wheel off and PM me a pic I can explain how to remove it.
Good Luck!
  #3  
Old June 24th 17, 08:03 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 580
Default 1987 Cobra Trailer Brake drum removal

Based on my older Komet and 1992 Cobra (they both use ALKO axles): remove the grease cap, then remove the cotter pin and large spindle nut. The outer wheel bearing should easily pop out in your hand and the brake drum should be removable with just a little tug.

In the real world, the spindle nut comes off easily but everything else is stuck together, which is probably where you are now. Make sure the brakes are off. Back off the manual adjuster by using a screwdriver to click the teeth of the toothed "star wheel", accessible from the inner side of the backing plate (crawl under the trailer and you'll see a slot in the back of the steel plate the the brake drum almost touches, possibly with a rubber plug.. The direction is marked by an arrow, which I think tightens it. To loosen it, use a second, smaller screwdriver to hold the pawl away from the starwheel and turn it.

If that doesn't help, with cars and vans, one technique is to rap the face of the drum sharply with a big hammer a few times to knock it loose. But you could crack the drum so for my trailers, I've used a 2- or 3-jaw puller, possibly with (IIRC) short lengths of chain or longer bolts or other jury-rigged device to pull the drum off. It only takes slight movement to break it free, then it should slide off. Older AL-KO axles don't, I believe, have a retainer screw that most be removed; the drum is held on by the wheel and lug nuts. They also don't have threaded holes into which you can insert bolts and tighten them up, forcing the drum away from the hub.

If the bearings are damaged, removing the inner race of the inner bearing may be difficult, requiring judicious application of heat (torch) and large Vice Grips. The parts--bearings and grease seal--are available here in the U.S. but you may have to order them so don't start this repair on Saturday morning expecting to have the trailer driveable the same day...or even week..

Google how to clean and pack the existing bearings or packing new bearings, and how to remove the grease seal (probably bending it in the process) and replacing it with a new grease seal, and then reassembling it and retightening the spindle nut correctly.

If the brakes got the whole hub assembly pretty hot, you might want to replace the springs inside the mechanical drum brake itself when you replace the brake shoes. The springs pull the brake shoes away from the inside of the drum when the brakes are released so if those springs are not strong enough, the shoes could hang up causing even more overheating.

Take photos of everything you disassemble to make reassembly easier. The AL-KO mechanical actuators are very similar to conventional hydraulic drum brakes but different enough that it can be difficult to reassemble a brake if you don't know where all the parts go.

Chip Bearden
"JB"
  #4  
Old June 24th 17, 01:23 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 23
Default 1987 Cobra Trailer Brake drum removal

Brake drum just fell off. Leaving the back plate and spindle. Now we need to get those off. I have seen Cobras that have a bolt, 17mm allen takes it off. This Cobra the bolt is not there. There what looks like a carriage bolt head. No way to he a wrench on it.
  #6  
Old June 24th 17, 04:30 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 23
Default 1987 Cobra Trailer Brake drum removal

Bolt appears welded to axle arm. Cannot remove spindle either.
  #7  
Old June 24th 17, 05:51 PM posted to rec.aviation.soaring
Papa3[_2_]
external usenet poster
 
Posts: 753
Default 1987 Cobra Trailer Brake drum removal

On Saturday, June 24, 2017 at 11:30:39 AM UTC-4, wrote:
Bolt appears welded to axle arm. Cannot remove spindle either.


I've worked on a number of these over the years, so I can't remember exactly which version is which. But, I would start with finding part numbers and hitting Google. There are a number of catalogs available online that show the components and in some cases very nice service instructions. It sounds like your version may be one of the earlier ones where the brake backing is integral to the spindle. It may not in fact be possible to remove.

Of course, Spindleberger is probably the best bet...

P3
  #8  
Old June 24th 17, 05:51 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 580
Default 1987 Cobra Trailer Brake drum removal

On Saturday, June 24, 2017 at 11:30:39 AM UTC-4, wrote:
Bolt appears welded to axle arm. Cannot remove spindle either.


AFAIK, if you're looking at the backing plate and spindle, you've gone as far as you can go without cutting/welding. Assuming the entire assembly didn't get hot enough to anneal/soften the spindle, why do you need to do any more disassembly? Replace or reline the shoes, think about replacing the springs, inspect the bearings/grease seals and replace if necessary, repack with grease, and put it all back together.

Chip Bearden
"JB"
  #9  
Old June 24th 17, 10:16 PM posted to rec.aviation.soaring
Dave Nadler
external usenet poster
 
Posts: 1,610
Default 1987 Cobra Trailer Brake drum removal

Probably you're already aware, but just in case: If I understand correctly (not certain), the drum can be damaged (embrittled) if it got too hot, and also the spindle itself (though less likely).

Make sure the spindle is OK (shows no signs of overheating). Later models of the Alko axle allow replacement of the spindle but it sounds like yours does not? If there's spindle damage, just get a new axle assembly (including drums and brakes) from W&W.

Make sure the drums aren't damaged as well. If you're lucky, you can re-machine and paint the drums, replace the bearings, shoes and springs (kit available from W&W), and retain the axle and spindle.

NOTE: When corresponding with W&W regarding parts, send them a picture of the Alko part description which is on a plaque riveted to the bottom of the axle assembly (under the square tube running wheel-to-wheel).

Hope any of that is helpful!
Best Regards, Dave

PS: Please don't ask me why I know this...

  #10  
Old June 24th 17, 11:54 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 580
Default 1987 Cobra Trailer Brake drum removal

PS: Please don't ask me why I know this...

Good point about drum damage. Speaking hypothetically, that could take the form of a small crack in the hub, the thickest part of the cast iron drum in the center where the bearings run. Aside from the implications about structural integrity of the drum, this could allow grease to leak out of the center of the hub and be flung up onto the brake shoes and machined braking surface of the drum. Well, maybe a little more than hypothetically....

Chip Bearden
"JB"

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cobra trailer brake heating up Eric Greenwell[_4_] Soaring 14 August 14th 18 05:48 AM
Brake Drum needed for a 1984 Cobra Nick Kennedy Soaring 4 June 27th 15 03:29 AM
FS Cobra brake drum w/new bearing Hartley Falbaum[_2_] Soaring 1 December 3rd 11 02:05 PM
Source for Cobra Trailer Brake Shoes Chip Bearden[_2_] Soaring 1 September 22nd 10 02:48 AM
Older Cobra trailer brake oscillation Brian Bange[_2_] Soaring 9 March 10th 09 08:41 PM


All times are GMT +1. The time now is 03:45 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.