How reliable are older ADL E400MMCs ?

[DD12]

Does anyone know if the older E400MMCs (now approaching 9 years old) have good reliability ?

My IMPRESSION is that the older version / older examples (locally) are too unreliable, and are expensive to repair / upgrade (?)

Does anyone have reason to believe that the newer MMCs will be any better, over the next 5 years (say) ??

ALSO, some time ago, Cummins beefed-up some of the engines they are / were making -- does anyone know if any of these were fitted to the more recent MMCs ?

THANKS.

Note to Moderators:- IF this post MUST go into a different thread, please move it there, please do not delete it.
THANKS.

 

[Resuwen]

Thousands of them running all over the country every day

 

[1D53]

The 17 plates Arriva have running round West Yorkshire seem pretty faultless.

 

[W176 XMA]

Does anyone know if the older E400MMCs (now approaching 9 years old) have good reliability ?

My IMPRESSION is that the older version / older examples (locally) are too unreliable, and are expensive to repair / upgrade (?)

Does anyone have reason to believe that the newer MMCs will be any better, over the next 5 years (say) ??

ALSO, some time ago, Cummins beefed-up some of the engines they are / were making -- does anyone know if any of these were fitted to the more recent MMCs ?

THANKS.

Note to Moderators:- IF this post MUST go into a different thread, please move it there, please do not delete it.
THANKS.

Mechanically they're not too bad, some usual wear and tear items but it's mainly on the electrical/emissions side they have more issues, derates (limp mode) is a common theme a lot of the time it's down to needing a DPF regen or sensors but sometimes can be wiring problems or needing a whole new DPF assembly

Plastic hoses and connectors on the adblue and coolant systems are also prone to failure after years of getting hot and cold they become brittle and break

 

[37114]

I guess the question is what sort of reliability is expected from a 9 year old bus? It is unlikely to do 365 days a year in traffic without a breakdown if you don't have an appropriate preventative maintenance plan and are prepared to replace parts that may have wear and tear or are near design life. I suspect some E400MMC are more reliable than another operators E400 classic and vice versa depending on how well they have been looked after. Equally some will say a Volvo or Scania bus will be better than an ADL as they are more solidly built but again the ADL have historically been more frugal, lighter and cheaper.

As an aside, the Cummins engine is similar to those fitted to some 7.5t and 17t trucks. I would never expect to run a 7.5t truck more than 6 years before expecting a level of faults way beyond what the first year of operation so it is pretty amazing that many buses get to 15 years.

 

[Dwarfer1979]

Depends on the bus (entire mechanical specification from engine through gearbox and axle settings), depends on the operator (how good is their maintenance but also how well attuned are they to the buses), depends on what type of work it has done in the past (intensive or easy, urban or interurban) and what type of work it is currently doing.

It is very difficult to provide blanket statements around things like this, even fairly unreliable buses may have operators who don't have trouble with them and reliable buses that an operator just can't get on with. Even if there is a known issue an operator who manages that issue pro-actively will see vehicles as reliable where an operator who waits for that issue to arise may see them as unreliable.

One of my earlier employers bought a batch of early Tridents and struggled to get 50% availability when only 5 years old and then bought a batch of Volvo B7TLs 2 years later which were almost bullet proof whilst a later employer accumulated a large collection of second hand early Tridents which the local operations team loved and never had an issue with but the couple of inherited Volvos were disposed of early as they couldn't get on with them. Different buses doing slightly different types of duties at different operators producing very different results.

 

[DD12]

Thanks guys for all the interesting info and sensible comments in your above replies.

 

[mattb7tl]

I have heard middle life vehicles (around 7-8 years) are the most reliable as engineers know the buses inside and out and issues are well documented so they can do quick repairs and implement preventative measures as the vehicles should still be in good condition. I can vouch with 1D53 about our YX17 batch at Arriva Yorkshire.

 

[W176 XMA]

I have heard middle life vehicles (around 7-8 years) are the most reliable as engineers know the buses inside and out and issues are well documented so they can do quick repairs and implement preventative measures as the vehicles should still be in good condition. I can vouch with 1D53 about our YX17 batch at Arriva Yorkshire.

Well said, generally if you have a lot of vehicles of the same age you get a run of common issues roughly around the same time

 

[Teapot42]

For their X17 Gold service, Stagecoach in Chesterfield had a batch of 6 64 plate Scania E400s, then later got a batch of 8 68 plate E400MMCs when the service was extended.

The MMCs have since moved on to Cumbria, but towards the end of their time in Chesterfield it felt like not many days went past without one failing. The Scanias however never missed a beat and are still in regular service seemingly without problem.

Bustimes suggests that only 4 of the MMCs have been out today and one looks to have failed. Another is tracking oddly, but probably a mis-track.

 

[Mwanesh]

The West Midlands Early Platinum MMCs are 10 years old and most over half a million miles.They are still reliable

 

[Russel]

The West Midlands Early Platinum MMCs are 10 years old and most over half a million miles.They are still reliable

They aren't doing too bad for buses that are on the road 12 hours a day!

 

[Hyebone]

The MMCs have since moved on to Cumbria, but towards the end of their time in Chesterfield it felt like not many days went past without one failing.

The X17 MMCs' reliability was shocking. I'm fairly certain the engines were tuned differently to standard to better cope with the demanding route that is the X17. They sounded different and performed much worse later on in their lives.

The Scania E400s still outperform any decker in our fleet; regularly managing long stretches without being off the road. That's a topic for another thread however.

 

[nick291]

The one's with First West Of England are fairly reliable, they do rattle like crazy though.

 

[TheGrandWazoo]

Bustimes suggests that only 4 of the MMCs have been out today and one looks to have failed. Another is tracking oddly, but probably a mis-track.

Big caution on the bustimes for the Stagecoach fleet in Cumbria. They are often employed on Sellafield work so just because they don't track, it isn't to say they are VOR

 

[Mwanesh]

They aren't doing too bad for buses that are on the road 12 hours a day!

Some are on the road for 21 hours .

 

[cactustwirly]

The older E400s seem quite bad, seem clapped out and slow. Some examples have spent months off the road

E400MMCs seem more reliable unfortunately, I hate the things uncomfortable and rattly. Reading buses seem to have specced awful thin seats on them compared to the other ones.

I like the Dark blue hydrogen ones, much better interiors but don't seem to stray away from the 33

 

[Russel]

The older E400s seem quite bad, seem clapped out and slow. Some examples have spent months off the road

E400MMCs seem more reliable unfortunately, I hate the things uncomfortable and rattly. Reading buses seem to have specced awful thin seats on them compared to the other ones.

I like the Dark blue hydrogen ones, much better interiors but don't seem to stray away from the 33

Some of the oldest original E400s are coming up to 18 years old now though, so they aren't going to be as reliable as newer E400MMCs.

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Some are on the road for 21 hours .

True.

To give NXWM credit where credit is due, they seem to keep on top of maintenance quite well, they must be one of the last big operator to use first gen Gemini B7TLs on a daily basis that are 22+ years old!

 

[cactustwirly]

Some of the oldest original E400s are coming up to 18 years old now though, so they aren't going to be as reliable as newer E400MMCs.

== Doublepost prevention - post automatically merged: 26 Nov 2025 ==



True.

To give NXWM credit where credit is due, they seem to keep on top of maintenance quite well, they must be one of the last big operator to use first gen Gemini B7TLs on a daily basis that are 22+ years old!

The examples I'm talking about are only a few years older than the E400MMCs.

 

[Gc1986]

You have to give credit to Stagecoach South West they seem to have been trident retirement home for last 12-18 months

 

[al_557]

Stagecoach East use 65/66/67 and 69 plate E400 MMC's on long distance routes 905, MK1 and X5

 

[TheGrandWazoo]

You have to give credit to Stagecoach South West they seem to have been trident retirement home for last 12-18 months

TBF, there's equal numbers really in West, South, and South West, with a handful in the Midlands. Suspect that many would've gone now if a) they'd not won a load of work in Cornwall/Devon and b) some of the cascades from Manchester weren't in a worse state!

 

[DD12]

Thanks everyone !

I have also done a Google search asking what improvements were made with the E400MMC compared to the classic model, -- and there were plenty, although I haven't yet spotted any improvements to the standard Cummins engine and transmissions.
Also, the introduction of Euro 6 emissions equipment seems (all makes) to be problematical (from what I've read).

 

[TR673]

Also, the introduction of Euro 6 emissions equipment seems (all makes) to be problematical (from what I've read).

One of the most common methods manufacturers use to comply with Euro 6 is to deliberately make the engine run hot, to achieve a more complete burn of fuel within the cylinders and reduce the amount of 'nasties' coming out of the exhaust. That puts all the engine components under a greater thermal stress and are more prone to failure. Plus there are exhaust filters and such with finely calibrated sensors that can go wrong. So low emissions and engine reliability are basically at odds with each other.

 

[Russel]

You have to give credit to Stagecoach South West they seem to have been trident retirement home for last 12-18 months

The amount of Tridents around Devon did surprise me when I was there in August.