Servicing AL-KO brakes.

[Gareth111278]

Hi.
I'm a quailifed HGV mechanic & I'm wondering about servicing the brakes on my caravan, its on an AL-KO chassis.

i know I need new hub nuts but is there anything else thats not obvious to be checked whilst the drums are off?

Does anyone know the torque setting for the hub nuts?

Cheers Gareth

 

[Sproket]

Plenty of information on the procedure can be seen here

The flanged hub-nut, located
under the dust cap, used to keep the
brake drum in situ, is a ONE-SHOT
NUT (ie. must only be used once). If
removed it must be replaced with a
NEW flanged nut - torqued to 290 ±
10 Nm (214 ± 7.5 lbs/ft).

 

[colin-yorkshire1]

yes, and before servicing slacken the h'bake linkage off, and after servicing adjust the wheels first and then the linkage or the auto reverse might not work correctly,

 

[Gareth111278]

Thanks guys.
That all sounds easy enough, I'll get in over the pit at work & check it over.

 

[Gareth111278]

Thanks for the replies, just one more thing.

i've looked on E-bay & there's varoius sizes [32mm / 36mm etc] , i don't suppose anyone knows the correct size for a 1994 AL-KO single axle??

 

[Sproket]

Might be just as easy to remove a wheel & measure the flats on the nuts....
Whats the MTPLW of your van or ( GW ) ?

 

[Gafferbill]

This is a link to a very good company that will stock and supply any parts you might need including service kits.
Your axle will almost certainly be an Euro axle and these are graded in axle weights with correspondingly different parts available. There should be a plate on the axle that gives you this information

http://www.western-towing.co.uk/index.html

Exploded diagram of Alko brake drum with ID information........

http://www.western-towing.co.uk/acatalog/Brake_Spares_Diagram.html

 

[Gareth111278]

Thanks to both, I was just being lazy , trying not to have to pull a wheel off!
Its 1200kgs MTPLM , I'll find the data plate & give that company a bell.
Thanks also for the exploding diagram !

 

[Gareth111278]

Thanks agian for all the info. I finaly got it over the pit yesterday. The hub nuts are 32mm so I orderd a pair of those. The brake cables & the long rod are also corroded badly.
I've orderd a pair of brake cables, is it ok to just make the brake rod by turung a thread onto a length of steel bar
Other than that standing [since august] hasn't harmed it too much, The battery is now 100% flat though :-(
I've just pulled the brake rod off, the spring unit is OK so its just a case of getting a length of M10 bar & running a tap down it, doesn't look too hard at all.

 

[Pinto]

Torque settings are in the handbook - or they are in our VIP.

 

[paul1103]

Hi Gareth,
When adjusting the brakes always start at the hub, ignore any comments about loosing the brakes linkage at this stage. When adjusting the brakes make sure you only rotate the wheels in the forward direction. With the hubs off, check the linings, there should be 2mm thickness on them. Replace the hub and torque the hub nuts up to 290nM + or - 10nM. Then pull the handbrake on and off a couple of times to centre the shoes, then leave it off. Then check the free play at the balance bar, on each Bowden cable, this is where the brake linkage meets the bBowden cables (sorry if I'm teaching you to suck eggs).. There should be between 5 - 8mm movement on the cable before the brakes apply. Adjust each drum until you get this, each time centering the brakes before measuring. When done you may find the drum is catching the brake shoes slightly when rotated forward. Then put the handbrake on and the balance bar should then be parallel to the axle, if both sides are set up correctly.Then go to the front of the van and under the hitch and check the lever that goes from the brake linkage up to behind the damper(draw bar). It should just be resting on the back of the damper when the handbrake is off. You can adjust the turnbuckle on the linkage, if there is one, to achieve this. There may be an energy store fitted at the front, on the brake linkage, which looks like a long cylinder with a braket over it, the braket going towards the rear. If there is, then there should be 2mm spacing between the end of the braket and the cylinder. Adjust this gap and then everything should be ok. Best of luck, Paul

 

[Gareth111278]

Thanks Paul.
Sounds like I expected it to, i was going to print out the PDF above or just use the Haynes manual, but what you said is all clear, not teaching me to suck eggs at all!
The one thing I'm supprised about is that you don't adjust the shoes until they bind then back them off 'X' amount. Then adjust the cables to suit but you live & learn! bYes I have the energy store Its all set up on my new brake rod, i've notched the balance bar to take the new type cables so it shouldn't be too hard...

I'm doing it tomorrow so we'll see.

thanks again.

 

[colin-yorkshire1]

Hi Gareth,
When adjusting the brakes always start at the hub, ignore any comments about loosing the brakes linkage at this stage. When adjusting the brakes make sure you only rotate the wheels in the forward direction. With the hubs off, check the linings, there should be 2mm thickness on them. Replace the hub and torque the hub nuts up to 290nM + or - 10nM. Then pull the handbrake on and off a couple of times to centre the shoes, then leave it off. Then check the free play at the balance bar, on each Bowden cable, this is where the brake linkage meets the bBowden cables (sorry if I'm teaching you to suck eggs).. There should be between 5 - 8mm movement on the cable before the brakes apply. Adjust each drum until you get this, each time centering the brakes before measuring. When done you may find the drum is catching the brake shoes slightly when rotated forward. Then put the handbrake on and the balance bar should then be parallel to the axle, if both sides are set up correctly.Then go to the front of the van and under the hitch and check the lever that goes from the brake linkage up to behind the damper(draw bar). It should just be resting on the back of the damper when the handbrake is off. You can adjust the turnbuckle on the linkage, if there is one, to achieve this. There may be an energy store fitted at the front, on the brake linkage, which looks like a long cylinder with a braket over it, the braket going towards the rear. If there is, then there should be 2mm spacing between the end of the braket and the cylinder. Adjust this gap and then everything should be ok. Best of luck, Paul

hi, all good stuff however I have only one comment to make " anyone who has done a set of brakes where he drums are worn and have a ridged edge knows that the drums won't come off unless the adjusters are backed off first,

 

[Gareth111278]

Hi , just done the brakes.
Not very difficult is it? I got it all built up & set up as best i could then had to get it off the pit as i needed to get a bus in, can't complain as they let me use the place! As I towed it the short distance to the storage area it felt like the caravan was 'banging' into the car when braking. The hitch isn't easy to pull out & I can't push it in so i'm sure the damper is ok.
The end of the brake rod is adjusted propperly to the Over run lever, I think I might have left too much travel at the cables.

I think I need to get it back in & go through it again TBH

 

[hortimech]

Hi, if the caravan is banging whilst braking one of two thing is happening, either the damper is kaput or the brakes need adjusting (and if you don't adjust them the damper will soon be kaput).
If you followed the instructions from earlier, then I am not surprised the brakes don't work properly, there is a stage missing. You need to adjust the brakes on each hub before adjusting the linkage. Please download this from Al-Ko:
www.al-ko.co.uk/edit/files/handbooks/caravan-chassis-handbook.pdf
Give it a read, I am sure it will help you. Oh and by the way, you do not need to remove the hub to adjust the brakes.

 

[Gareth111278]

Thanks, I did adjust the hubs , wind them up until they lock then back them off. I didn't back them off exactly the same amount though .
TBH I think I've left the brake rod too slack at the back end, I'll pop it back over the put & adjust all the slack out of it.

Cant be much wrong

 

[Gareth111278]

Thanks, I did adjust the hubs , wind them up until they lock then back them off. I didn't back them off exactly the same amount though .
TBH I think I've left the brake rod too slack at the back end, I'll pop it back over the put & adjust all the slack out of it.

Cant be much wrong

 

[colin-yorkshire1]

hi Gareth,
ps, thats another reason to slacken off the linkage " you can't forget to readjust it at the end" the reason the van slams into the car when braking is too much damper travel, adjusting the brake linkage should cure the problem, there is no need to worry about the brake drums being adjusted by different amounts as each brake will have it's own dynamics and the fact that one works clockwise and the other anti clockwise, but then as a professional mechanic you know this allready.

 

[Gareth111278]

Thanks Colin. That all sounds like I'd expect.
Yesterday I adjusted the rod up & was suprised how far it went up. Good advice a bout not slackening the linkage but I'd repaced the bowden cables & the brake rod so I was setting up from new. I just need to get it out for a quick spin & check it's braking nicely now.
Away with it for the first week of the school hols so I need it right

 

[Gareth111278]

FINALLY.....
I got it out for a quick test drive, its braking nicely now, so smooth that is difficult to know if the caravan brakes are working!
They definalty are though. I couldn't stop all that weight without them!

Thanks to everyone for the help & advice!

 

[Hazzar]

Hi gareth just a quick one for you i might be to late now but i am caravan tec when setting the brakes on the hub always adjust them up fully locked then back them off 13 clicks this is the factory standard from alco hope this helps PS dont forget to put some grease on the draw bar threw the nipple with a grease gun this can cause the van to bang about a bit .