Brakes Rear brake servicing
HarryMann: T25 rear drum brakes are common across all models and years.
They rarely get serviced, and whilst usually meeting minimum MOT requirements year after year, they are often doing less and less of the braking. With more weight aft than many other vehicles, and a heavier vehicle overall, they make a big difference when working well. Additionally T25 handbrakes have a poor reputation, again no doubt as they just squeeze through MOTs time and time again.
Brake shoe specs: Standard lining thickness: 6.0mm (0.236") Oversize lining thickness: 6.5mm (0.256") Wear limit: (0.098")
Brake drum specs: Diameter: 252mm (9.921") Max. dia. after machining 253mm (9.960") (use oversize linings after machining 0.5mm (0.020") or more) Wear limit: 253.5mm (9.980")
It is often best to buy new drums and standard shoes if the brakes are out of spec. A noticeable step in the drum friction surface at the inside edge can make removing them difficult, and prevent new shoes bedding in properly.
The VW part no for rear-brake shoe service kit i.e. springs and retainers (2-off, both wheels) is:-
251 698 545 (about £10 and well worth it even if just the retainers have rusted away)
Brickwerks sell all the parts for servicing your rear brakes The Bendix shoe kit they sell also comes also include the various springs and the pins with retaining cups. Bear that in mind when comparing the cost to lower spec offerings from GSF and Just Kampers  They also sell a kit with the back plates included...  but you will need to remove the rear hub nut in order to fit this. 
Getting the drum off
Loosen the road wheel nuts slightly. Jack up the side or the whole rear and place axle stand(s) under the outer edge of the rear cross-member just inboard of the jacking point. Lower onto the axle stand and shove the vehicle around to make sure its secure. Remove the road wheel.
Remove the two retaining set-screws if present (the wheel will hold the drum on if these bind against non-standard wheels). When brake drum and shoes are well worn, this can be difficult.
The drum develops a lip at the back, where it overlaps the inner edge of the shoes. It also seizes/rusts onto the hub which is the lesser of the two problems... deal with this by striking it a healthy blow with a club hammer (not a small hammer that does damage.) You are trying to 'spring' the thin circular plate front plate that goes over the studs - which will flex safely - not distort the circularity, so strike square and flat onto the face, moving around. Start with medium blows and look closely at the join line around the hub behind the large 46mm nut for signs of release.
Alternatively, you can undo the 46mm nut (see Wiki elsewhere for tools) and take the drum off with the hub and splines. Alternatively a good small screwdriver can be edged into the retaining screw holes, but take care to do minimal damage, alternate between both holes. Deburr the inner edges before refitting!
To get a worn drum off over the shoes:
A badly stepped brake-drum can hook up on the dges of the shoes. Ensure the handbrake is right off and cable has no tension on it. There are access holes at the rear of backplate (see link below) for the adjuster at the top. The aim is to loosen the adjustment off by spinning the self-adjuster, clicking it over bit by bit, but this is not an easy task! It'll usually either be seized, or the ratchet pawl will be locking it, but some persevere and loosen things off this way. Sometimes driving the drum through holes in the back-plate can ease it over the shoes.
Phade: Here's another quick tip too when it comes to removing rear brake drums to get at the wheel bearing housing. Remove the brake drum and wheel hub together (as my VW booklet suggests). This will make access to the wheel bearing housing a lot easier. If a brake drum is difficult to get off, do NOT apply heat (also mentioned in the VW booklet), use a large gear puller instead
Re-fitting those shoes and springs
Photograph it all first? or memorise the springs. Haynes has a procedure, Bentley doesn't. Start at the top (strong) spring.
Make sure you put the top spring on the right way round and the correct side of the adjuster, they're all handed. Free up the adjuster well, set in neutral position to start. Long nose pliers, long thin but strong screwdriver, or a slotted one. It might help to have the bleed screw open on the cylinder (clamp the flexible hose) if you do it this way...
...fit the spring with shoes loose, fit one fulcrum and lever other over the top cylinder with a healthy screwdriver, minding the rubber gaiters. Fit the handbrake cable and the bottom spring together then the shoe retaining cups (healthy pair of pliers just gripping edges, other hand behind backplate holding pin in place, line it all up and aim to do it in one go, elbow against body and lean into it, twist 90 degrees and release gently - they're the easiest of the lot)
If you lube the contact points/shoe fulcrums and supports, do this after its all assembled, Zinc based (Castrol PH) was always the right stuff (today MOS2 is often quoted), be sparing, long thin screwdriver to work it between the pivot points.
The handbrake pull-up self-adjust rarely works (as the manuals suggests), even when all is in good working order, so just keep popping the drum off (unless it's ridged badly) and clicking it up a bit on adjuster. Until it just rubs in one spot without binding after having centralised the shoes with the hand or footbrake (very hard). Otherwise, try adjusting self-adjuster clicker from access hole at rear, first check which way you need to flip it. It's best though to get the adjustment as close to final as possible first time, by slipping drum half way on, and guesstimating. Don't assume brakes are binding badly unles you're sure you've centred the shoes well, with handbrake or footbrake.
You might also inspect the brake pipe over the radius arm where it goes through the plastic clip for corrosion - I've had one burst there, as have others.
NB. Check not overheating after a good run out (spit-sizzle test).
After about 500 miles, pop the drums back off, knock them out, dust out with a vacuum or dry clean kitchen brush (dustpan and brush type). Lots of tapping on back plate and shoes to loosen dust. Inspect where shoes making contact, won't be much unless you're lucky, but will gradually bed-in and contact over most of surface.
Re-adjust up, should be less binding as bedding-in progress, making it easier to adjust up tighter
Hacksawbob: This weekend I mainly fixed a rear brake
PICTURES TO FOLLOW My brake pedal was pulsing and was diagnosed as a warped rear drum by syncronuts it passed an MOT but I found it annoying and unsafe. In terms of difficutly I would say that this is a 2.5 out of 5 spanners difficulty so long as you have the right tools and are methodical most mechanically minded people should accomplish this. Just remember that these are what are between you and almost certain death of yourself and your loved ones and those bods that may just be in the wrong place at the wrong time. Take your time, this took me all week end as I put the trailing shoe from the wrong side of the van on 2 times before I worked out why it wasn't working for me. Dont skimp on tools or replacement items, a few quid here could really cost you dear in the long run. Apparanly GSF do a higher and lower quality brake clinder. The better one is FAG branded and costs a tenner. I got the cheaper one at £6 but only cos I didn't know that there was a better one until Aiden told me about it. Brickwerks sell bendix cylinder and and all the other parts for this job, they are usually much better quality I have had to trim down the hand brake cable from GSF as it was too large to fit the back plate.
sendiw I have just fitted a new brake cylinder but after pressing and releasing the brake pedal the pistons withdraw away from the brake shoes thus giving me more brake travel. It is the rubber dust covers that are pulling them back. I have disassembled the cyl. and found that there is no spring between the two pistons.I phoned GFS today and they said "we've had this problem before".Apparently there are brazillian and German Cylinders and the Brazillian ones dont have a spring in them but the German ones do. So if you buy some, make sure you get the German cylinders or check to see if there is a spring in them before you leave the shop or you may find that no matter how much you bleed the system and adjust your brakes you will still have too much travel in your brake pedal
The parts for a complete rear brake service were about £60 from GSF this included a brake cylinder two pairs of shoes (L+R) and a drum.
I was lucky in that my old drum came off quite freely it can take some persuasion with a lump hammer and a cold chisel and hitting left then right, top to bottom to free it up. Also corrosion anywhere along the way can stop you in your tracks and put you in a "no way out without extra parts" situation. Make arrangements for alternative transport before you start this job.
Tools you will need for shoe removal
A safe method to jack and support your vehicle and 19mm socket to remove road wheels
For drum and shoes only
a pry bar for removing refitting return springs
set of spanners
lump hammer and cold chisel
two pairs of pliers one needle one standard.
2.5mm-4mm cable ties for spring compressors
For cylinder removal
brake clamp £4.00 halfords
11mm brake spanner £5.00 halfords (like a ring apnner with a chunk missing to go over brake pipe, an absolute must have))
7mm open end spanner for bleed nipple
ideally plus gas but at least wd40
13mm spanner for clynder bolt.
brake bleed kit and compatible brake fluid
1. Put Plus gas the rear brake union now if you intend to remove the cylinder, also follow the brake pipe and put some on the unions on the forward edge of the trailing arms aswell, just incase the brake pies are corroded and disintegrate when you remove them. It may well be an idea to inspect those pipes they are a bugger for corroding. Your local garage may be able to make a spare up for you if it breaks.
2. put van in gear baut release the hand brake!
3. jack van, remove road wheel
4. remove drum (see above!) Mind the dust that is in it brake shoes have asbestos in them wich is bad for you. Also generally you should wear a dust mask if you are wire brushing any of the back plates etc.
5. Unhook adjuster spring and slaken off adjuster with a screw driver (looking from rear of the van near side slakens anti clock. off side is clockwise) and remove it note the long prong on the fork goes to the rear and on the far side of the shoe.
6. release return springs.
TOP TIP I found the best way was using a pry bar, the crank in the end gives you just enough of an angle to push the sping from between the hub and the shoe. saves your knuckles, about 2 hours and many curses.
TOP TIP it is possible to wedge the shoes open agaist the hub and leave in situ if you only need to do the clynder and not the shoes. Hovever there is some finger loosing presure in them springs so go carefully!
7. Remove shoe retaining springs and cups, use the two pliers. Use the standard pair to hold the cup and the needle pair to turn the centre pin 90 degs. Remove cup spring and pin. Do both sides.
6. Pull top of shoes from away from cylinder then bottom. Shoes should come off altogether now after you un-hook the handbrake cable. Note how the upper and lower springs connect. Also note that the rear 'trailing shoe' has the handbrake cable arm and hook towards the outside of the van.
8. Now would be the time to remove and refit the brake cylinder if you are doing it. Apply the brake hose clamp to the rubber fexi pipe it the forward edge of the trailing arm. Undo the brake pipe with your 11mm brake spanner and. DO NOT be tempted to use a standard 11mm spanner it will end in rounded nuts, tears, and brake fluid. Go easy make sure you are going the right way and not tightening them (think about it, look at it from the rear just to make sure you are taking them anti clock.) Move it a touch, then nip it up again, undo a bit more, keep going back and forth undoing it a bit more each time. Cover the end of the brake pipe with a small peice of plastic bag to prevent dirt getting in to it.
9.Undo the 13mm bolt on the back of the cylinder.
7. Remove the brake cylinder, it may have rusted on to the back plate.
8. At this point you could refit the shoes the springs will be dead easy to locate as there is no cylinder to work against. Get them all nicely seated with all srings and handbrake cable atattched, Pull the top away from the centre pivoting around the lower seating point, then wedge them open with something about 4cm across like a sturdy block of wood. I used a wirebrush handle. It might be possible to hold the shoes open by fitting the adjuster bar now and extending almost fully. Alternativley you could fit the cylinder then the shoes and try and get the springs on with the pry bar, either way has its pitfalls. The pry bar method may be slightly safer.
8.5 Refit the shoes retaining cups sring and pin
TOP TIP This can be a real bastrard of a job. What I did was to use two cable ties to compress the spring down, then fit evry thing nice and easily with no tension, once in place and pin has been rotated to the lock position take a pair of wire cutters and snip the cable ties releasing the tension.Pull out the remnaints with needle nosed pliers, you may need to pick the odd bit out that got trapped. smaller 2.5mm cable ties get trapped easier but give you more room to fit the cup thicker cable ties are easier to pull out afterwards but give you less clearnce, maybe one of each and cut the smaller one first?
9. Refit new cylinder, clean the old bolt and do it up with a dab of copper grease.
10. Refit brake pipe union to cylinder and tighten (dont over do it!)
10.5 lubricate sparingly with correct grease on points as described by clive above.
11. Locate the top edge of each shoe into the cylinder retaining slot, then remove your wedge being carful not to trap body parts as the tension releases from each return sping.
12. Re attatch the adjuster bar if you havent already and put a a small ammont of tension into the shoes. make sure long prong of fork is on far side of shoe and pointing to the rear. Then attatch the adjuster spring.
13.5 get some some to press the bake pedal whilst you watch what happens just make sure it is all working aas it should. (the self adjusters are a pretty pants desigh and may not be doing there job you can see this and make a note that you may need to manually adjust the shoes until you fix it.
14. Align shoes with back plate as best you can then fit drum. Haynes says you want about 1.5mm either side. As you cant see whats happening (apart from through the hole on the back of the back plate you have to have a few goes to get a best fit, not too tight not too loose. The drum should turn with little or no scraping, take vehicle out of gear! (MAKE SURE OPPOSITE SIDE ROAD WHEELS ARE CHOCKED FRONT AND BACK so van doesnt roll away!) and rotate thu drum.
15. Apply the foot bake hard several times , and try the drum for freedom of movement, continue adjusting until you are happy or need a pint, come back and adjust some more. re assemble road wheels and take for a very short , flat test drive checking brakes frequently as you go. Take the tools that you would need if you have to do an emergency roadside adjustment.
Thanks To Aiden for his advice I had along the way.
Other rear brake information
There are 3 qualities of cylinders from GSF, only buy the better ones. They are either ATE which is the OEM manufacturer, like what VW fitted, or the are FTE, which is part of the FAG group, which are very good quality
Showing correct set up, notice the heavy duty return springs under the adjuster come up from below the retaining prongs / hooks on the backplate. If you fit them the other way they will interfere with the self adjust mechanism.
picture by metalmick8y
The adjuster forks have two distinctive ends, one side has a stubby end and one side has a chamfer, the chamfer goes on the inner (ie back plate) side. the other end has a longer prong which also goes on the inner backplate side.