C8A/C15 rear brake: adjustment tool?
 

All,

I have been trying to adjust the brakes on my C15. I need to take off the brake drums, but the brakes are binding so I need to back off the brake shoes.

But my C15 does not have the adjusting pinion as per the manual, only the slots in the brake backing plate like the front brakes have.

As the rear spring sits close to the brake backing plate, there is no room to use a regular screwdriver to engage the teeth on the adjusting cover of the wheel cylinder.

Who has solved this riddle before? Is there a special tool or a trick?

Thanks in advance!
Hanno

Per the manual
 

To be clear: the rear brakes on my C15 do not have these adjusting pinion shafts:

So I tried using the method for the front brakes, but because of the rear springs, there is no room for the screw driver handle:

Attachment 109508 Attachment 109509

inside the drum
 

Tried to take a pic of what the inside look like:

Attachment 109512

Get a brake adjusting tool. It has an end like a screwdriver (but wider) and the shaft is bent over about 35°. If the angle is not right for your specific application, then heat the tool and bend it to where it does work.


The tool can usually be had for less than $10.

Special tool #27257
 

Hi Hanno


I agree with Rob you need a brake adjustment spoon tool. I made mine which I will photograph and post. There is an issue of clearance to the springs. The things to remember is which direction you need to move the tool back off each end of the cylinder.


Cheers Phil

Thanks, that makes perfect sense but I didn’t know it existed. My ‘65 VW used the same adjustment system, but there a screwdriver did the job.

A Dutch friend has stepped forward, I can borrow his tool.

To be continued!

Hanno

Special tool #27257
 

Hi Hanno

Here is the little tool made for my HUPs first brake job, 40 years ago.

Attachment 109534Attachment 109535

Cheers Phil

Thanks Phil,

Did you make this yourself or is this an off the shelf tool?

Just tried my friends home made tool - sadly that didn’t work...

Hanno

Can you fit a drift in the hole then hit that with a mallet? It might get things moving. It sounds like you are due for some replacement parts.

Did it not work because the angles were not right, or because the adjuster is siezed? If siezed, spray a little penetrating oil at it through the little hole, using the straw that comes with most oil spray cans, and let it sit for for a few days. You will have to clean the drum and shoes afterwards with brakecleaner or alcohol.

If it is the angle of the adjusting tool, then heat the tool with a torch and bend it to the angle you need.

Special tool #27257
 

Hi Hanno

I made it because non of the commercial ones worked. Made from some key stock heated and bent to shape.

Will take a better photo with dimensions and angles.

If you wonder about the Special Tool # 27257 I have a tool drawer where I put all the tools I've made over the years for the CMPs.

Cheers Phil

Waterman Special CMP Tool Co.
 

Thanks for all the tips and hints, guys. The tool I borrow was made up from an old screwdriver. Angles were not entirely right and I could not put enough leverage on it.

It does not help the cylinders may be seized. I will be soaking them again in WD40 and copy Phil's tool. I have a 10 mm wide cold chisel, some 25 cm long, which I reckon would fold up nicely along Phil's dimensions - if you could please post the dimensions, Phil?

If the brakes are rusted solid and I cannot back off the brakes, I guess I have no choice but to pull the hub + brake drum with force?

Hanno

If you are unable to back off the adjusters, and even then are unable to free up the drum from the shoes (I take it you are saying the drum will not turn?) then what you could try is to unbolt the cylinder before pulling the drum. I am not up on the smaller brake systems, but if there are bottom anchors, or anchor pins, I would try and remove them at the back of the backing plate as well.

If the drum will turn, but just not back off, then use a bar or wooden handle (ie pick axe handle) on the wheel studs (protect the threads of course) and turn the drum while pulling the drum away from the hub. Again, whatever you can remove for the anchors may help remove the drum.

Hanno,

If you do end up pulling the hubs, you need a kent-moore J870 wrench (attached - the one I have is missing the tommy bar) for the special locking nuts on the C15 rear axle. You can use a punch and hammer if you don't have that wrench, but be careful not to damage the nuts. :(

From my recent experience, the brake linings on my C15 were pretty much welded to the drum. To confirm what Rob suggests, I ended up 'working backwards' and unbolting the backplate from the axle, unbolting the wheel cylinder and disassembling that way.

Owen.

Special tool #27257
 

Hi Hanno


Can't find my protractor to measure the angles, but here are the the measurements and the outline of the tool on 1/4" graph paper.


Cheers Phil


Attachment 109562

Hanno, make sure your hand brake is backed off. Do the cables still function as they should? They need to be backed off to their maximum for your best chance. I would see if there is movement between the inner and outer cable,(both sides) and then dis-connect the cable up top.

Always wondered what this tool was for. I never really looked it over too closely. Now I know.

Another option is to drill some 3/8 holes in the backing plate right behind the brake shoe surfaces. Slip in a small screwdriver and pry the shoes away from the brake drum surface. You may be surprised at how little effort is required to unstick the shoes away from the drum, as opposed to trying to turn the drum.

Of course, that is after checking the park brake cables as Lynn suggests.

You can cover the holes with inspection plugs or weld and grind the holes shut afterwards.

Thanks again for all the tips and info :thup2:

Alex van de Wetering looked up and cross matched the lock nut number 473636 as being the same on a GMC truck. So the GMC tool should work on the C15 lock nut as well.

Will report back later!

Hanno

Attachment 109565 Attachment 109566

Please do Hanno! It seems the GMC tool is not as fancy as the one Owen and Jordan showed, but hopefully it does the trick.

Alex