1981 XJ750 Seca Rear Drum Brake Shoe Replacement

Hey everyone, first timer doing this stuff and know my rear brake needs new shoes so figure I'll share maybe to help others. I've never done this work before and in fact never worked on a bike before so if I say something that sounds stupid, don't hesitate to tell me .

First thing is first, I've been planning out each tool/part I'll need since I don't have all that many tools, mostly just basics (sockets, JIS drivers, pliers, small wrench set):

- Dust mask, rubber gloves and rags for cleaning
- Brake cleaner, degreaser, stiff brush
- Grease - Synthetic and silicone
- Torque wrench
- New brake shoes and springs
- 2 new cottor pins (axel and brake tension bar)

Here are the generic steps I'm planning on:

1. Remove rear tire
2. Remove old shoes
3. Clean and use some fine sandpaper/emery cloth to lightly sand/polish the drum
4. Clean/re-grease brake cam
5. Clean/remove rust on axel
6. Reassemble with new parts

While the tire is off, also figured I'd check the movement in the swing arm , anything else I should check/take note of/clean when doing this? Going to be putting my order into chacal probably tonight or tomorrow so want to make sure I have most everything on hand to get this done right (and hopefully in just a few hours).

Hope all is well with everyone on this beautiful Saturday afternoon!

 

Looks like you have everything needed to service the rear brakes. While you are there with tools check the oil level in the rear drive. Just remove the rear plug, the oil should be at the lower threads. Get a manual if you don't have one, it will come in handy.

 

I have actually looked into possibly changing the drive shaft oil just for peace of mind knowing it's done and experience doing it, thanks man.

Got a Haynes manual and electric copy of factory manual. Factory seems very hard to follow the organization but I like the explanations, I can see why multiple manuals are recommended.

 

Go ahead and change it. A quart of 80/90 gear oil is only a few bucks. Its worth it for piece of mind.

 

Timely -- I'm in the middle of doing a writeup for this very procedure. My summary was a bit more detailed, but you've got the gist of it.

There's an o-ring around the drive splines on the rear wheel -- might want to check that to make sure it's there and intact.
Clean and regrease the splines.
When removing the axle -- if it doesn't want to come out easily, resist the temptation to hammer on the castle nut to drive the shaft out... you'll be buying another if you do.
Once the axle is cleaned up, put some grease on that bad boy. Makes it much easier to remove the next time around.
Do not blow out the brake dust -- vacuum the stuff up.
Check the bearings and repack them.

And by all means, drain and refill the final drive unit. Hypoid gear oil.

 

Some people like to file a chamfer on the leading edge of their shoes...

 

New rear shoes are generally pre-chamfered.

At 15K miles, I'd strongly suggest checking your valve clearances SOON;

and get after the 30-year old FRONT brakes as well.

 

Very true, thanks.

Great tips, will take note of this and check the o-ring. I didn't list everything and wasn't entirely specific as I plan on taking pictures along the way while doing it (probably this fri/sat).

I am working to build up to removing the head cover but want to have a little more wrenching under my belt before diving in too deep. I haven't been riding the bike and also have a car so have time. The front brakes are probably going to be right after this since they need caliper rebuild, new hoses and I'll probably throw new pads on just to do it. I appreciate/understand your concern on the valves as I definitely don't want the engine seized BUT also keep in mind, this is a first bike, got it cheap so IF I did do something like that, I'd rather f*** up big time on this bike than another. (part of the reason I bought a 30 year old bike) Kinda funny that every day I spend on this forum and reading the manual, I find more and more to fix/work on/check but I'm having a good time learning this stuff.

 

you can do it, get that head valve cover off! just take it slow, make sure you got all the tools in place and if you follow fitz' valve shim replacement guide to the letter you be just fine. i was able to do it and ive never doen anything like that before, its alot easier than you might think.

 

That definitely gives me the encouragement to get it done. You're referring to this thread right?

http://xjbikes.com/Forums/viewtopic/t=1 ... valve.html

If so that was the one I started reading the first time fitz told me to check the valves .

 

Totally, it's the first thing I did on my xj and couldn't believe how easy it was.

Just go slow abd follow fitz's tutorial by the letter.

Hit up Dave (higfiddles here on the forum) tell him i sent ya and let him know what shims you'll need and he'll give you the hook up.

After you remove the rear axle, the wheel will still be caught on the drive splines. Don't get frustrated, just wiggle wiggle wiggle and wiggle it back an forth some more, and eventually it will come free. Do NOT force anything. Just keep wiggling. Trust me, you just gotta have faith.

A torque wrench is also a good call if you have access to one.


You can do it!

 

Sounds like I'm going to have a busy weekend next week. I'll have to hit up higfiddles for shims. Very nice man, thanks.

 

That's what i like to hear!

 

Tackle the Engine Related issues, ... first!

There's no sense in overhauling anything else until you know the Plant is healthy and will perform up-to-snuff.

• Compression Test
• Valve Clearances
• Ignition related
• Carbs Cleaned and "Clean-tuned" ... Diaphragm Piston Bores De-oxidized.
• Thorough Carb overhaul and cleaning.
• Everything necessary to insure the Bike will run right.

 

Looking up pulling the bearings as well and from what I'm seeing I shouldn't need any crazy tools. Mostly some type of driving tool (seen large sockets used) to squarely seat them and some patience/elbow grease.

Might know a guy at work with a bearing removal tool though.

Edit: Forgot to refresh the page when I got home and missed your post Rick, very good information and much appreciated. That stuff is on the list and I understand you saying to do it first but to me this whole project is a learning experience as much as anything else. I'm starting small and working up to more complex work.

 

Alright, pictures to come soon but just about done. Decided to just do the brake shoes (and replaced o-ring on wheel) since I was running short on time and worried about rain. Also, I did the bearing test described in the manual to test for play and these seem fairly solid, it looks like someone may have replaced them at some point in the past few years. So I still have the rear bearings and plan on doing them but it'll be another day. At this point I'm just happy that I got everything apart, cleaned and back together. Going to go on a slow ride around the block to test things out. I realized when cleaning that no mech was ever going to clean the stuff as good as I was doing since it's my bike . All in all this took me about 3.5-4 hours but ~75% of that was cleaning/scrubbing and I had a lot of fun/learned a lot while doing this.

 

Left rear before:


Right rear before:


Rear tire removal:








Brakes:






Cleaned rear brake drum and brake cover:



Right rear after cleaning:


Left rear after cleaning:


Left rear with tire back on, pic was taken before new cottor pin installed but there is a new one:


I found the sanding sponges to be quite nice for cleaning things but damn if the hardest part of this work wasn't just cleaning out 30+ years of grim in all the nooks and crannies. I'm thinking this will be the case with most of the work when I start but as I keep up on things it'll be easier and easier.

Cheers all and happy riding this weekend.

 

Grab a Bottle of your wife's, daughter or girlfriend's finest RED Nail Polish and give that Brake Wear Pointer a little pimp.

Nail Polished Indicator
Stainless Allen Pinch w/ washer.
Staked Camshaft Mark even with Pinch split.
Re-finished and Polished Spring.
Nylon and Stainless Washers at ends of Spring.
Wire Brushed Threads on Brake Adjust Rod.
Re-finished / Polished Adjuster Nut & Trunnion.

 

Very nice Rick and a great idea, thanks man. As I worked on things today, going over the bike seems like a smaller and smaller task (just less intimidating). I mean I know it'll take lots of time (and elbow grease) but already researching valve shims and thinking I'll be ordering parts for that next week and also parts for front brake caliper rebuild.

So then once I get valve shims replaced, both front/rear brakes done, I figure the other big thing to do to ensure I have a smooth bike for a long time is clean/rebuild the carbs. And while I'll do this work I'll keep cleaning things little by little making it look nicer and hopefully in a bit I'll make her look real pretty with some new paint.

To think...I had thought I'd only keep this bike for 6 months and now it's looking like it might be a few years . Something about this old style has me a bit hooked.

Edit: And totally disconnecting the battery when doing the valve adjustment (along with most all work), seeing SilentRaven's engine is painful.