Rear brake
Driving into town I noticed an unusual lack of "go" which could not be accounted for by a headwind. I stopped to investigate, and smelled hot brakes. Careful searching for the hot wheel identified the offside rear hot with a trace of smoke from the grease on the backplate - bother! I let it cool a bit and drove slowly, the wheel cooled off and did not overheat again, but something was obviously wrong.
At home I chocked the front wheels (ESSENTIAL!) and jacked the rear corner, careful to get the jack under the crossmember not the floor. The wheel dragged when spun by hand, handbrake off. Here's what I did and found, with thanks to Paul Humphreys for his description of the operation earlier on the Yahoo group mailing list.
First, slacken wheel nuts slightly with tyre on the ground or handbrake applied, if working.. The nuts are 19mm, I used a telescopic wheel wrench. I was fortunate that a previous mechanic has greased the studs and nuts, they removed easily after jacking the car back up. Wheel off - it is pleasantly and surprisingly light weight. Once the drum is exposed the axle nut can be seen - 18mm again. this has to come off as it not only retains the bearings but the drum, which unusually carries the bearings, and the shock absorber bottom. You need to get round the back and hold the nut on the other end of the stud. If you haven't got two 18mm sockets a 3/8 Whitworth fits nicely. Here are some pictures -
BTW - don't forget to back up your jack with an axle stand or similar sturdy solid support. Axle stands are cheap and avoid getting you squashed flat in a stupid accident. We've had our stands for years, bought from a motor accessory shop and will hold far more weight than an Aixam can bring down.. Unlike your arm, head, leg etc.
Here I've already got the drum off, courtesy of a rubber mallet and some wriggling with the other hand. Taking out the split pin and clevis pin from the handbrake lever should give more slack in the shoes and easier removal. You'll want the pin out eventually anyway, to remove the brake lever. I had to hammer the brake lever back a bit on mine, it was stiff.
Sorry about the manky picture, forgot the macro button on the camera. The spring will normally press the brake lever to the left - mine was stuck.
A couple of pictures of the drum, removed. Don't inhale the dust!
Here is a pic of the shoes etc. all in place. Note how the springs and clips are fitted, you'll need to put them back. I worked the tops of the shoes out a bit until they would come off the wheel cylinder, then I "folded" the shoes toward me. The friction washer bit sits on a pin, you can see the end peeping out. Once the shoes were off I could get out the offending brake lever, seen below.
I wiped the grease off, wire brushed some of the rust, then gave it a good talking to with a bench vice, hammer and penetrating oil. The pivot then would move freely, so I wiped the rusty oil out and smeared a trace of Copaslip assembly grease in instead.
Reassembly, as they say, was the reverse of the above procedure. The brake shoes won't be centred until the footbrake has been applied, so may catch slightly when the drum is refitted. Make sure the wheel nuts are lightly greased - the copper assembly grease is ideal for this. Re-grease the brake clevis, I brushed on ordinary lithium bearing grease for that.
I'll have a look at the other side brake, weather permitting, as soon as I get the chance*. Or sooner, if I get a mysterious lack of speed and a hot wheel again. Also, ideally the Nylock stiff nut on the axle stud should be replaced by a new one if it is removed. I got some from a local nut and bolt specialist, they have a different outer size and fit a 19mm socket. Buy some spares, they are cheap!
* Done!
Back
to mechanics page