Air brake canister 1993 917 AF

[VerMonsterRV]

Mine continues to leak as the brakes are engaged. That makes me think the diaphragm is failing. Please correct me if I'm wrong. I'm new to these systems.

I am guessing you are correct. I know the diaphragms in our front cylinders had hardened a bit and had a few cracks in them. Not sure if they were at the point of leaking but I am glad they are now new. I didn't try to rebuild the rears as I was told it was too dangerous given the parking brake spring. Guess there is a bit of tension in there. The DT aftermarket ones weren't terribly expensive so I went that route. If all you want to replace is the combination cylinder then it only involves removing the incoming air lines (those Voss fittings, you don't have to remove the hose as the fitting will unscrew with the hose in place) and the 4 bolts that hold the air canister in place. If you have the factory original wedge units they are held in place with a couple of allen head screws so no problem, if they are aftermarket and don't have the set screws then with drum will likely need to come off. The wedge unit is what the cylinder bolts to, so you need to hold it in place if the set screws are not there (our aftermarket PE brand wedge units didn't have the set screws).

 

[Fadeagray]

If anyone is able to find a source for the brake canister vent elbow, please share. I could use a couple of them.

 

[Neil]

If anyone is able to find a source for the brake canister vent elbow, please share. I could use a couple of them.

It might have been mentioned earlier in the thread, but do you have a MB part number for them

I will look on UK sites

Neil

 

[Fadeagray]

It might have been mentioned earlier in the thread, but do you have a MB part number for them

I will look on UK sites

Neil

I do not have an MB part number. The brake canister vent elbow looks similar to the cracked ones on my 1982 DAF YA-4440, DAF part number 4720-12-173-8426. I’ve had a bit of a problem finding them in Europe.

 

[Neil]

Maybe someone with access to the EPC could help with a part number

Neil

 

[VerMonsterRV]

Maybe someone with access to the EPC could help with a part number

Neil

I looked at the EPC, it doesn't seem to break down the parts for the cylinders (well at least for our VIN). And @Neil , if we do meet up on the way south and if you have a Windows laptop we can load up the EPC if you want.

 

[Fadeagray]

I looked at the EPC, it doesn't seem to break down the parts for the cylinders (well at least for our VIN). And @Neil , if we do meet up on the way south and if you have a Windows laptop we can load up the EPC if you want.

View attachment 754759

Thanks to all for taking the time to search for a part number!

 

[Neil]

we can load up the EPC if you want.

Sounds great thanks

 

[theangrychicken]

I haven't been able to track down any OEM/Bosch, Wabco, or Euclid canisters. But I ordered a replacement canister from eBay and I think that DT unit arrived to a work site I'll be at shortly. Hoping to have that installed and broken leaf spring swapped out at a shop on the week of the 11th. Anyone have a line on Wabco or Euclid parts in Europe?

Next year, around April, I'm going fly into Guatemala to revisit a project that we stated before the pandemic. I'm thinking that is when I want have the brakes at all 4 corners refreshed by a shop. I haven't find a specialized Mercedes truck place that can secure parts and do the work. But I did connect with terra-exp earlier this year and they could secure parts to refreshen everything within the drums for about $5k shipped. I did not ask them about access to canisters at that time.

I'm doing a lot of other maintenance work and modernizing over the next 1-2 years while living/working out of my truck. The running plan is to head to AK with friends and afterwards, do a solo trip back to Latin America. I'd like to sort out and do as much preventative maintenance done before. Some of the places I plan on being at for awhile are very remote and I won't have access to parts or mechanics.

VerMonsterRV, in a different thread, you mentioned servicing the wheel bearings. Do you mind sharing where you got those? Thanks!

 

[VerMonsterRV]

I haven't been able to track down any OEM/Bosch, Wabco, or Euclid canisters. But I ordered a replacement canister from eBay and I think that DT unit arrived to a work site I'll be at shortly. Hoping to have that installed and broken leaf spring swapped out at a shop on the week of the 11th. Anyone have a line on Wabco or Euclid parts in Europe?

Next year, around April, I'm going fly into Guatemala to revisit a project that we stated before the pandemic. I'm thinking that is when I want have the brakes at all 4 corners refreshed by a shop. I haven't find a specialized Mercedes truck place that can secure parts and do the work. But I did connect with terra-exp earlier this year and they could secure parts to refreshen everything within the drums for about $5k shipped. I did not ask them about access to canisters at that time.

I'm doing a lot of other maintenance work and modernizing over the next 1-2 years while living/working out of my truck. The running plan is to head to AK with friends and afterwards, do a solo trip back to Latin America. I'd like to sort out and do as much preventative maintenance done before. Some of the places I plan on being at for awhile are very remote and I won't have access to parts or mechanics.

VerMonsterRV, in a different thread, you mentioned servicing the wheel bearings. Do you mind sharing where you got those? Thanks!

The wheel bearings were ok, but the grease had gotten hard. Each bearing hub requires 600 grams of grease. You need to replace the lip seal, they are a generic size so I ordered them here in the USA. You do need a special keyed socket which is a Mercedes specific tool(there are several different ones so yours may not be the same as mine). I found one on eBay.de, and they even would ship to the USA. You also need a 12 point 50mm socket to get that special outer nut off the hub. You are supposed to replace that each time as you peen it to lock it in place. I think I ordered those from SpareTo in Latvia. Mercedes recommended to do this every couple of years.

About the oem canisters, if I remember right (and I might be wrong as I have gotten a bunch of various parts, and several of them were NLA) they were NLA.

The brake job was more physical than technical. Parts are heavy and some hammering is required. Any decent shop with good mechanics/tools should be able to do it.

On another note, why do you have a broken leaf? On our truck the leaves had a molded in ridge in the center. We didn't do that in the states. So a replacement will be flat and will rub weird on the original leaves ridge. We did that as a stop gap when we got the truck as we had 2 broken leaves. But then got new leaf packs out of Germany as we were sagging in the rear anyway.as the leaves were tired. We got some parabolic ones and they are great.

 

[theangrychicken]

I'm not sure why it broke. But I'm on the 3rd owner of this truck. The last 2 owners also lived/traveled in it full time. The truck has been to nearly 50 countries and on 5 continents. It's been used quite a bit and it could be just stress from over time. The original owner bought a spare front and rear leaf pack and the prior owner passed these on to me. So luckily I have one and it doesn't need to be custom made. A shackle was placed to keep the spring from working itself to the side and shearing the air bag.


I received the DT canister yesterday, thanks for helping me find that!

I apologize for my newbie questions. But I'm not a mechanic and this is my first big truck. I want to make sure I have all the parts for the swap. Are the connections for the air lines universal or standardized? I'd like have that torn elbow replaced along with any other fittings that are most likely worn.

 

[Joe917]

The front wheel bearings were replaced in Chile along with the tie rods when the engine was rebuilt and clutch replaced.

 

[theangrychicken]

Thanks Joe!

 

[theangrychicken]

Just closing the loop here. The DT diaphragm that VerMonsterRV worked great (thanks man!). I had help at bettstruckparts.com in San Leandro, they also have a few other locations on the west coast and AZ. One of their sites can also custom make leaf springs. They swapped out a spare leaf spring pack that I provided and that canister in under 3 hours. I was out the door for around $500 USD including parts/labor. The mechanics were pretty chill guys and fun. A mixed group from Mexico and Guatemala. I'd def go back there for suspension needs again.

 

[theangrychicken]

Another issue has come this morning in my right rear brake.
My truck was parked on a mountain for about 4 days for snowboarding. Snow accumulated to just over 2’/half meter around where it was parked. After I left, I noticed the parking brake would not fully engage. I made it a truck shop where my friend works and they were nice enough to look at it although they would not be able to work on it (they do fleet service only). They did not take anything apart for inspection. But they believe the recent/newer air canister is working. But the service or parking brake is not engaging in the right rear. The mechanic suspected a brake failure but cannot 100% confirm. There is plenty of pad life.

I’m wondering if anyone had a line on replacing any associated hardware, springs, etc. I would likely have a shop service both sides as a preventative maintenance. I’m also very open to feedback/suggestions.

This is my first big diesel truck and very much still on the learning curve.


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