Air brake canister 1993 917 AF
- Thread starter theangrychicken
- Start date
where_the_heffalump_roams
Active member
100%.
Both rear drums should be replaced since one it warped and the shoes are worn asymmetrically. I haven't pulled the fronts, but it's possible they will need to be serviced. Since everything needs to be ordered, (sourcing is the big challenge), might as well source everything at once to reduce downtime and shipping costs.
You have been so helpful! I'm still wanting on Hans to look into parts.
It would be rad if you happened to have some links or contacts where you sourced your parts and shared the with the group.
VerMonsterRV
Gotta Be Nuts
I have ordered parts from a number of different sources in Europe. eBay.de works well sometimes for finding NOS parts that are no longer available (but only some will ship to the US, but I have gotten some parts). I also have used eBay.uk (they seem to be better at shipping to the US), SpareTo.com, Braem.com (you have to request a price quote but they respond quickly) and Trodo.com. There are a few others and some of these only offer aftermarket parts. Trick is you can usually find the parts online, but then a lot of the companies will not ship to the USA (the above ones will). I have tried to use ForwardToMe.com as a forwarder with only mixed success. The last round of brake parts were supposed to be sent to ForwardToMe for repackaging and shipment to the USA. 6 out of the 7 packages were returned to sender as ForwardToMe couldn't get their shipment address correct. Was a bit of a mess and I ended up having to work through refunds and finding other ways to get the parts.
where_the_heffalump_roams
Active member
I agree that OE is necessary. I also believe it's cheaper to do it right the first time. So it really does depends on the part itself and how it's used.
In the race world, a friend of mine is one of the fastest guys in the world in his element. He brakes a lot of axels and over time, figured out that the auto zone axels hold up and break just as often as custom, big power rated axels he was buying. He uses auto zone axel now that come with life time warranties and simply swaps them out when the go.
VerMonster, I'd really be interested in hearing if you sourced your drums in the USA, and if so, where. Shipping cost is going to be pretty hefty for those heavy items. And I'm sure I speak for many reading these threads, we appreciate you sharing all this info!
In the race world, a friend of mine is one of the fastest guys in the world in his element. He brakes a lot of axels and over time, figured out that the auto zone axels hold up and break just as often as custom, big power rated axels he was buying. He uses auto zone axel now that come with life time warranties and simply swaps them out when the go.
VerMonster, I'd really be interested in hearing if you sourced your drums in the USA, and if so, where. Shipping cost is going to be pretty hefty for those heavy items. And I'm sure I speak for many reading these threads, we appreciate you sharing all this info!
where_the_heffalump_roams
Active member
For anyone interested.
This is the current pricing for parts that I was able to source.
Brake Drum: $ 630.40
Brake Lining as per set of two: $ 606.00
Spring: $ 22.95
Sprag (wedge actuator): Unit $ 1722.80
I'm sure you can find better pricing for drums and brake shoes. I was really surpliced to see the pricing on the wedge units though!
This is the current pricing for parts that I was able to source.
Brake Drum: $ 630.40
Brake Lining as per set of two: $ 606.00
Spring: $ 22.95
Sprag (wedge actuator): Unit $ 1722.80
I'm sure you can find better pricing for drums and brake shoes. I was really surpliced to see the pricing on the wedge units though!
theangrychicken
Member
That's the pricing from Unimog Canada for those parts. I don't know if anyone has been able to source drums or shoes within N. America, but that would reduce shipping time and costs.
It's not recommended to routinely change the wedge/sprags. I'm guessing they are actually simple units that can be serviced. However, I wasn't able to find a place where I am that had experience with them and would service them. My plan is to replace my unit. Once that is done, I'll keep the old one and see if I can learn how to service it myself. If I'm right, it's the same that is used in all 4 corners. It was recommended that I change my drum since it had considerable heat damage. Machine could could true it and remove the uneven wear. But there was considerable blue discoloration from heat that could compromise its longevity and use.
It's most likely cheaper to turn your drums if possible and reline your shoes. I think Vermonter posted his cost and he was only out a few K, and that included changing the brake canisters (not priced above).
Here is what Terra-Exp sent me a while back. I think this a more realistic cost if you are just servicing your drums. This trucks were mean to go for a long time with heavy use. It's quite possible for many, that the drums, shoes, and wedges don't need to be replaced.
It's not recommended to routinely change the wedge/sprags. I'm guessing they are actually simple units that can be serviced. However, I wasn't able to find a place where I am that had experience with them and would service them. My plan is to replace my unit. Once that is done, I'll keep the old one and see if I can learn how to service it myself. If I'm right, it's the same that is used in all 4 corners. It was recommended that I change my drum since it had considerable heat damage. Machine could could true it and remove the uneven wear. But there was considerable blue discoloration from heat that could compromise its longevity and use.
It's most likely cheaper to turn your drums if possible and reline your shoes. I think Vermonter posted his cost and he was only out a few K, and that included changing the brake canisters (not priced above).
Here is what Terra-Exp sent me a while back. I think this a more realistic cost if you are just servicing your drums. This trucks were mean to go for a long time with heavy use. It's quite possible for many, that the drums, shoes, and wedges don't need to be replaced.
RoamIt
Well-known member
Thanks, I've been working under the mindset of rebuilding/replacing things now while I still have a well equipped shop area to level set maintenance. Rather do it here than broke down on the side of the road in the middle of nowhere.
Not that breakdowns won't happen, but if I have the larger systems rebuilt, it would most probably be the smaller issues.
I have no idea what my brakes look like, my rig only has 57K miles, so they 'should' be fine. But since the air canisters need replaced I was thinking full rebuild. But I may reconsider that
Not that breakdowns won't happen, but if I have the larger systems rebuilt, it would most probably be the smaller issues.
I have no idea what my brakes look like, my rig only has 57K miles, so they 'should' be fine. But since the air canisters need replaced I was thinking full rebuild. But I may reconsider that
where_the_heffalump_roams
Active member
I get that 100%.
I'm wanting to take my rig on some longer, more remote trips, where I access to parts/mechanics will be more challenging. I was hoping at a place where I could do that, but I'm not there yet myself.
Just keep this in the back of your head, some of these parts can literally last several trips around the continents and more. Consider pulling your drums and having a look around before you dive in and buy parts. That will also help you become familiar with the systems.
I'm wanting to take my rig on some longer, more remote trips, where I access to parts/mechanics will be more challenging. I was hoping at a place where I could do that, but I'm not there yet myself.
Just keep this in the back of your head, some of these parts can literally last several trips around the continents and more. Consider pulling your drums and having a look around before you dive in and buy parts. That will also help you become familiar with the systems.
Neil
Observer
Out of interest how long do you expect a set of brakes to last.
I had mine all apart 2 weeks ago , I needed to replace a rear cylinder.
All the brakes were original from 1988. 145000 km
Loads of meat still on the linings.
All functioning perfectly.
The actuators for the parking brake and the drums look perfect still
I suspect that they will probably last another 250000 km at least.
Is this unusual, have I just been lucky
Neil
I had mine all apart 2 weeks ago , I needed to replace a rear cylinder.
All the brakes were original from 1988. 145000 km
Loads of meat still on the linings.
All functioning perfectly.
The actuators for the parking brake and the drums look perfect still
I suspect that they will probably last another 250000 km at least.
Is this unusual, have I just been lucky
Neil
Attachments
VerMonsterRV
Gotta Be Nuts
I think if the truck was well taken care of the brakes can last a long time. I am pretty sure though that in our trucks life as a firetruck they backed it into water to fill the central tank. This caused the wedge units and air canisters to rust internally and fail. Causing very odd wear on the linings. Best to start completely fresh.
I didn't get the drums in the the US. These are very specific to the truck and I couldn't find any here. I ordered them from Trodo, for some strange reason the shipping was pretty inexpensive. I think all parts, with shipping ended up around $2500. This is using aftermarket parts.
Another example, my diesel manual priming pump has started to leak. OEM is about $400, aftermarket $40. I think I'll buy 2 aftermarket and keep one as a spare.
VerMonsterRV
Gotta Be Nuts
Since I recently learned this (and it may be obvious to others) the wear indicator is the small round cutout the is on the edge between the 2 linings. Once this cutout is gone the linings need to be replaced or the rivets will soon start to contact the drum.
where_the_heffalump_roams
Active member
From what I can tell, brakes on these can go for 250K+ pretty easily. But with the parts getting older and older, it may be more difficult to find and replace parts. I want spares.
I think the wedge actuator can be used on all 4 corners. I ordered 2 to have one as a spare. I'm hoping that I can take apart my failed part and service it myself after it's replaced.
I ordered 2 replacement drums and I'll have see if these shoes can be ground down even, if not, they will just get relined. If the drums can be saved with machine work, I'll have spares.
I think the wedge actuator can be used on all 4 corners. I ordered 2 to have one as a spare. I'm hoping that I can take apart my failed part and service it myself after it's replaced.
I ordered 2 replacement drums and I'll have see if these shoes can be ground down even, if not, they will just get relined. If the drums can be saved with machine work, I'll have spares.
Attachments
where_the_heffalump_roams
Active member
I’ve been at a truck shop this morning but we are having some trouble with the parking brake still and we were hoping for some guidance from someone who is more familiar with the system.
When the service and parking brakes are applied, the pistons on the actuator are moving and the shoes are expanding to the drums. However the vehicle will still roll when the parking break is applied. It will stop with the service brakes.
The techs here are wondering if there is a valve that might be failing that we should be looking at? Is it possible there not enough pressure is available due to a failing valve that won’t put enough pressure on the system to allow the shoes to make enough contact?
Thanks I’m advance!
Sent from my iPhone using Tapatalk
When the service and parking brakes are applied, the pistons on the actuator are moving and the shoes are expanding to the drums. However the vehicle will still roll when the parking break is applied. It will stop with the service brakes.
The techs here are wondering if there is a valve that might be failing that we should be looking at? Is it possible there not enough pressure is available due to a failing valve that won’t put enough pressure on the system to allow the shoes to make enough contact?
Thanks I’m advance!
Sent from my iPhone using Tapatalk